External drain according to snip. Organized drainage from the roof: elements and device Organized drainage from the roof

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Unorganized and organized drain for pitched and flat roofs - basic requirements and recommendations

Gutters are an integral part of all buildings, performing a very important function - removal of melt and rain water from the roof surface.

If this is neglected, then water can flow directly along the walls themselves, enter the basement, which can lead to the destruction of the entire construction site.

In addition, the drain also performs a certain decorative role in the exterior of the entire building, so this fact must be taken into account during construction.

An organized gutter of a pitched roof - what is it and why is it needed?

To date, there are several types of drainage:

Disorganized.
Organized internal.
Organized outdoor.

Outdoor organized drainage is considered the most popular, so let's start the story with him. It is a whole system consisting of various gutters, drain pipes, fasteners and other parts that attach the structure to the roof and walls of the building.

This type of drainage has undoubted advantages over other types of drainage:

The organized drainage system is fully thought out, therefore all water ends up outdoors, i.e. outside the building. This suggests that moisture cannot exert its negative effect on the structure itself, which can significantly extend its service life.
The system is designed in such a way that All fasteners are within easy reach which greatly simplifies various repairs in case of breakdowns.
An organized drain can be done on your own, without the involvement of third-party labor.
An organized drain performs not only its direct function - it drains water from the roof, but also adorns the facade of the building. On sale there are modern materials from which the drain is made, so it is quite possible to choose the option of interest.

Elements of the drainage system

An organized outdoor drain is very well suited for a pitched roof.

For the arrangement of this system, the following materials are most often used:

The metal is galvanized. This material was most popular several decades ago, but now gradually losing ground to more modern materials. The average life of a gutter made of galvanized steel is 12 years.
PVC or plastic. Such material is now most popular in plumbing, which is explained by its low weight, as well as the relative ease of installation. The average service life can reach 30-35 years.
Copper drain. Such material outperforms all those named according to a variety of criteria, but there is one significant drawback is the high cost of copper itself.
Metal-plastic. Such material is considered relatively young, therefore, it is not as widespread as the previous ones. However, he combines the advantages of PVC material and galvanized metal Moreover, its service life can reach 50 years.

Gutter system

Organized flat roof drainage - why is it needed and how is it arranged?

An organized drain for a flat roof is also necessary to collect water from the roof surface, for its further transfer through the pipes of the drain. From the pipes, water flows into the sewer, into a water collection tank, or directly onto the ground itself.

The service life of a flat roof directly depends on the quality of the drainage system. That is why it is very important to follow the basic recommendations when installing a drainage system.

Installation of drainage on a flat roof is carried out in two ways:

On overhangs located just below the surface of the roof itself.
On specially equipped ledges.

The essence of the first method is the location of the funnels in close proximity to the roof overhang. In this case, the water flows down the drainpipes, which are installed in the channels under the funnels.

Organized internal drainage

Installation Rules and Norms (SNiP)

Organized internal drainage is a fairly popular way of drainage from roofs, because it can be organized regardless of the climatic conditions of the region.

Such a system includes several parts:

a funnel into which flowing water enters;
riser;
outlet pipe;
release.

It is necessary to divide the entire surface of the roof into sections.
One drain pipe should go for every 200 square meters of roof space.
It is necessary to observe the slope of the roof to the water intakes - it should be about 2%.
Under the building, a collector must be built to collect water, which must also be connected to the main sewer.
When installing the system, pipes of a certain diameter and length can be used. The diameters allowed are 10, 14 and 18 cm, and the length must be 70 or 138 cm.
In order for the system to work stably all year round, all risers must be located in a heated area.
The funnel must be built into the roof tightly so that water does not seep through the cracks.

Don't forget to regularly clean your drains.

Gutter installation

Unorganized drainage - what is it, advantages and disadvantages

Unorganized drainage from the roof suggests arbitrary runoff of water from the roof directly to the ground. This is achieved by a certain slope of the roof, while there are no structures and pipes for collecting water.

This method of wastewater disposal involves minimal costs, but there are a number of undeniable disadvantages:

Such drainage can lead to destruction of the foundation, because water will freely penetrate into its structure.
It is necessary to periodically change the waterproofing layer of the basement of the building, because water will get there as well.
It is also necessary to provide additional layer of waterproofing walls so that moisture does not destroy their structure.

It would seem, why equip such a drainage system at all, if there are so many shortcomings in it? However, such drains are found everywhere, but There are a number of factors influencing the feasibility of such a system:

There shouldn't be more in the building five floors.
The region should not be very rainy - no more than 300 mm of precipitation per year.
Such a gutter can be equipped on a pitched roof. In addition, there should not be paths and balconies under the slope.
The roof visor must be of sufficient length - at least 600 mm. This will provide at least minimal protection of the walls from moisture.

Unorganized drainage system

How is the drainage system?

We have already said that an outdoor organized drain can be completely built with your own hands. To do this, you will need the following elements:

Pipes for draining water. In this case, it would be more appropriate to use plastic pipes, because they are much easier to install.
Sealant for lubrication of cracks and joints.
Gutters.
Clamps and brackets holding pipes.
adhesive composition.
Funnels.
Anti-icing system.

Along the entire perimeter of the slope, it is necessary to install special brackets that will hold the trays for draining water. They are installed at a distance of 50 cm from each other, and are attached to the board, or to the last element of the roof sheathing.

The tray must be installed at a certain angle to the funnel with a riser so that the water flows down it on its own. The riser can be installed at an angle or straight, there are no special recommendations for this.

Drainage system device

Do-it-yourself roof drainage device:

Conclusion

The device of a drain is very important stage in construction of any object. If this matter is neglected, then such a building is unlikely to stand for a long time, and randomly flowing water from the roof can cause great inconvenience. This is especially true for regions where night frosts are a frequent occurrence. In this case, ice will form in the local area, which in itself is a potential hazard.

Country Expert

Source: http://expert-dacha.pro/stroitelstvo/krysha/vodostok/organizovannyj-i-neorganizovannyj.html

Outdoor drain

The system for removing precipitation from the roof plays a very important role in the construction of the building, drainpipes make it possible to transport them to the sewerage system as efficiently as possible, and thereby protect external building envelopes from wetting, and damage.

Outdoor gutter from a flat roof

When they say a flat roof, this does not mean at all that the overlap angle is zero. According to building codes, for a flat roof tilt angle provided no more than 5 °, which is more than enough for the water flow to drain to one edge.

At the same time, a person, being on such a roof, is completely does not feel any discomfort.

For a flat roof, it is also provided drainage system, in most cases these are internal engineering communications, laid down in the building project, however, you can often see external drains from a flat roof.

This option can be implemented in various ways. depending on the type of roof:

Rigid roofing from slate, metal profile, ondulin- since the water drains to all recesses at once, a common gutter is used along the length corresponding to the side of the slope and transporting all the water down the drain system;
Soft roof - bitumen, roofing felt, roofing material- the most common option for buildings with the possibility of going upstairs - overflow windows are arranged, for which a hole is made in the edge of the enclosing wall located on the inclined side.

The overflow window is a square or rectangular metal plate made of galvanized iron, with a hole in the middle and a branch pipe half a meter long. It is very important that the drain is located as close to coverage as possible which guarantees the most efficient water removal.

Snip for external gutters

Arrangement of external drains, as an obligatory element of engineering networks in buildings and structures, is strictly regulated by regulations and in particular SNiP 2.08.01 - 89.

The design of the drain, despite its apparent simplicity, if it does not meet the above requirements, will not be able to fully ensure the removal of moisture, which will inevitably lead to damage to the decorative coating of walls and foundations, as well as the penetration of moisture beyond the fence and into the basement.

document the height of the building and the type of drain are negotiated depending on this:

With number of storeys up to five levels inclusive, an external organized drain should be equipped;
With number of storeys up to two levels it is possible to arrange an external unorganized drain, while at the same time, peaks must be equipped above the entrances and balconies of the second floor;
With number of storeys from six floors and above an internal drainage system is being designed.

At construction of private houses, the height of which varies from one to three levels, external drains are equipped, more often of an organized type, since it is much easier to carry out maintenance in the conditions of one's own household.

Outdoor organized drain

Organized drainage involves the collection and transportation of melt or rain water, starting from the end of the roof slope and up to the storm sewer.

With prolonged contact of the outer walls with moisture, and especially the directed action of water jets, plaster and plinth fail, moisture penetrates into the basement, causing dampness, and through the walls, into the interior.

An external unorganized drain helps only partially protect the walls from this, but the basement of the building still remains in the affected area, so even in one-story buildings, preference should be given organized drainage.

Such a system also has disadvantages - a higher cost, and the need for regular cleaning, due to clogging with foliage, moss and branches. Main components of the system- these are horizontal gutters, hanging or wall mounting, plums and vertical drains.

There is a dependence - the more complex the roof structure, the more complex and drainage system, each of the slopes must be equipped with its own gutter, which is connected to the rest with a subsequent exit to the drain.

Internal drains: norms, SNiP

According to the rules of SNiP, all residential and industrial buildings must be equipped with drainage systems. This is necessary not for aesthetic beauty, but in order to protect the building from destruction by rainwater flowing from the roof. The strength of the water flow can be so great that the walls and foundation of the house will begin to collapse, and the soil around it will be washed away.

But there are exceptions to the general rule. SNiP norms allow construction without a drain in the following cases:

for buildings of economic type;
if the project provides for the laying of a pitched roof;
if the house is low, and the roof lines go far beyond the walls.

Most often, an external drainage system is installed on buildings. But in some cases, the installation of an external drain is impossible or impractical, for example:

buildings with a flat roof;
construction in a region with difficult climatic conditions involves heating the drain;
when the drainage system violates the aesthetics of the building.

In all these cases, the norms of SNiP provide for the installation of an internal drain.

What is the built-in drainage system

For the internal drain, the project does not involve gutters; its design is somewhat different from the more familiar external drain. Here the main elements are:

Pipes through which water flows. They are mounted inside the walls.

Funnels with a more complex design.

Drain pipeline.

Collectors or water intakes.

In fact, the design and construction of the internal drain is quite simple. But here the correct calculation and competent installation are very important, in which building codes are observed.

Cast iron is most often used as the material for receiving funnels. It has been used for over 40 years, and some experts consider cast iron funnels to be a relic, but practice shows that the calculation of the designers of the 70s of the last century turned out to be correct - cast iron is an excellent material for the manufacture of water intake funnels. It is very durable, does not corrode, does not crack under high water pressure, cast iron caps have sufficient weight so that they are not washed away by water flows.

Pipes for drainage, according to SNiP, must be at least 100 and not more than 200 mm in diameter. The norms allow the use of cast iron, steel, copper, galvanized, aluminum, plastic, asbestos-cement pipes. Most often they have a rectangular cross section, but there are also round pipelines.

Before choosing pipes, it is necessary to make a calculation by calculating the flow rate of rainwater through the pipeline, the throughput of the funnel, and the maximum possible amount of precipitation.

Steel is the cheapest option. But steel pipes cannot be installed in places unprotected from freezing. If the water inside the drain turns to ice, the steel pipe will break. In such cases, it is better to use a PVC pipe, it has a large thermal expansion. If the pipeline is made of metal, it must be soundproofed - the water hits the metal too loudly, there will be no silence in the house during rain.

The most reliable and durable drain is copper. However, the cost of this material is so high that copper pipes are used only as decoration for external systems.

The horizontal drain under the basement ceilings can be made of any material. Often there are concrete and plastic plums.

Water diversion

The initial calculation of the drain should assume a drain method. The norms of SNiP prohibit the use of domestic sewers for draining rainwater due to the fact that the system can become clogged with foliage, branches and other debris. It should be either industrial effluents, or storm drains, drainage wells. In private households, rainwater often drains from the blind area into the ground; guide channels can be made to divert water from the drain.

Classification of drainage funnels

Only careful calculation and analysis will help you choose the right intake funnels for the internal drain. These systems are of two types: flat and hood.

Flat funnels. According to SNiP, they are installed on absolutely flat roofs. Often such a roof is covered with asphalt or laid out with ceramic tiles. For the possibility of precipitation from a flat roof, at least a minimum slope is required - from 1%. The slope is made towards the funnel, and the funnel itself is located no closer than one meter from the edge of the wall (SNiP norms).

Cap funnels. Almost always made of cast iron. They are installed on pitched roofs with a slope of more than 1.5%. Such systems have a filter (assume the norms of SNiP), so the risk of clogging the drain is significantly reduced.

The bell funnel consists of four parts:

The cover, which is the visible part of the drain, is installed on the roof.

Housing installed flush into the thickness of the ceiling.

Receiving grille in the form of a cylinder with holes, reinforced with stiffeners.

filter element.

Important! The section of the roof where the funnel is mounted must be carefully sealed. If this is not done, the roof will leak.

Rules for installing an internal drain

The arrangement of the drainage system (sewerage and drainage) is regulated by the norms of SNiP. It is impossible to deviate from these requirements during construction, otherwise the project of the future building will not be approved by the relevant authorities. When equipping an internal drain and performing a calculation, it must be remembered that:

Funnels should be distributed evenly over the entire roof area, at an equal distance from the walls and from each other.

A slope should be provided towards the funnel.

On one branch of the pipeline, more than 20 meters long, there must be at least two funnels.

The vertical pipe and the funnel must be connected at right angles.

Pipeline connections must be reliable and tight (welding is required for metal).

If the roof consists of two parts, the height difference of which is more than four meters, a separate drain must be installed for each of them.

Any flat roof must have at least two funnels.

To clean the drain, the project should involve the installation of inspection and revision hatches.

Drainpipes can only be attached to risers in an elastic way.

The calculation of the pressure in the system should assume the maximum water pressure with clogged pipes.

Important! The design of the funnel includes a special valve that is responsible for ensuring that air does not enter the pipe. Therefore, the pressure in the drain is not too high. The internal system is also suitable for multi-storey buildings, even skyscrapers are equipped with it.

Classification of internal drains

Only a calculation will show which precipitation drainage system is more suitable in a particular case. There is a division into three types:

gravity system;
siphon design;
heated drain.

In a gravity drain, the pipes are never completely filled with water. The collection and disposal of precipitation is carried out through a pipeline located under a slope. Water randomly flows down a slightly inclined pipe.

The calculation of the siphon drain is more complicated, but also more efficient. The system only works when the pipeline is completely filled. The water column should start at the funnel and end at the end of the drain pipe. When the rain is too weak, the siphon drain works on the principle of gravity. If the pressure drops in the upper part of the pipeline (the rain weakens or ends), a vacuum is created in the middle of the pipe, it helps to suck the remaining water into the funnel and completely remove it from the drain.

Attention! Forced drainage is much more effective than gravity. But it is also more difficult to arrange: such a system must be absolutely hermetic, and the installation of temperature compensators (gaskets, seals) is not allowed in the seams.

Heating is most often needed by metal pipes or gutters of industrial unheated buildings. Drainage areas are heated by electricity or steam. The calculation of such systems should only be carried out by a specialist.

How to calculate the drainage system

At the same stage, when a house project is being developed, specialists should perform a calculation of the drain. Important factors to be considered in the calculation are:

Climatic conditions in the region of construction.

Average and maximum precipitation.

Features of the roof (slope, slope, complex elements, material).

The area of the house and the height of the walls.

Possibility of water drainage.

Given these parameters, calculate the number of funnels, their location, the diameter of the pipeline, the location of the drain.

Troubleshooting

The most frequent troubles in the drainage system are leaks and clogged pipes. To ensure the availability of the pipeline for repair and cleaning, it is necessary to provide for the presence of inspection hatches and inspection windows even at the design stage.

The internal drain, most often, is mounted under the finishing of the building. These are all kinds of sandwich panels, siding, insulation and other cladding materials. When mounting them, it is necessary to provide for all kinds of removable elements, hooks, hatches.

If the drain of an old multi-storey building has become unusable, most often, it is simply dismantled and replaced with a new one. Since it is very difficult to repair the built-in system due to its inaccessibility, clogged drainage pipes that could not be cleaned are duplicated with new ones. They are attached to the risers in the stairwells and in the corridors.

The internal drainage system will be effective only when the norms and requirements of SNiP are observed during its design. The building project should initially assume configurations, unlike external systems, internal drains are not mounted in an already built structure.

Sliding gate mechanism

What is a bidet toilet, its types, installation

Source: http://obrawa.ru/normy-vnutrennih-vodostokov/

Unorganized roof drain

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The organization of the drain has a whole list of positive aspects, which primarily include the safety of the structure from the destructive effects of rain and snow. However, is it always necessary to arrange an organized drain from the roof with a whole system of pipes, as well as various gutters. There are times when you can do just fine without it. Here we are talking about an unorganized drain, for the arrangement of which you do not need to spend money on the purchase of additional materials.

What does an unfinished drain look like?

Due to the appropriate slope of the slope and the complete absence of additional structures, there is an uncontrolled runoff of liquid from the roof surface. The simplicity of construction and the minimal cost of its arrangement attract many homeowners. However, do not forget about the negative aspects that can affect the integrity of the roof, and indeed the entire building.

An unorganized drain has a negative effect on the walls of the facade, accelerating their destruction. Therefore, in the process of their construction, an additional layer of waterproofing is required.
Even in areas where there is a minimum amount of precipitation, water will penetrate into the foundation, worsening its condition and slowly destroying it. To avoid this, additional drainage underground should be arranged to remove excess moisture.
Precipitation will also have an impact on the plinth. This indicates the need for periodic renewal of the waterproofing layer.

Given these shortcomings, the question arises whether an unorganized drain from the roof is necessary. To answer it, you need to familiarize yourself with the standards prescribed by SNiP 31-06, which clearly define the features of the building, allowing you to leave the drain unorganized.

Requirements and regulations

The main criterion is the number of floors in the building, which should not be more than five. Also, the amount of precipitation falling in a certain region should not exceed 300 mm. Only in such situations is it possible to do without laying pipes, gutters, as well as other material. Based on the requirements, an unorganized drain from the roof of the SNiP is created with a shed roof, which has a slope to the courtyard. In addition, the following factors must be taken into account:

under the slope there should be no footpaths, a roadway and balconies;
the peak of the roof should be equal to 60 cm or exceed these parameters in order to protect the building from moisture;
additional protection should be provided by a visor installed above the entrance.

Today, too stringent requirements are imposed on the design of buildings. However, caring owners, in order to increase the life of their houses, install a drainage system.

Type of drains

Drainage systems are of two types.

Internal, with pipes located inside the building. Such a device for organized drainage from the roof provides for water intake funnels on significantly underestimated sections of the roof. In addition, all valleys, grooves, roofing must have a slope towards the funnels.

Outdoor, located on the outer sides of the building.

On roofs made of metal tiles, sheet steel, asbestos-cement sheets, corrugated board and small-piece materials, an external drain is provided.

The main requirements for drainage systems look something like this:

the roof surface must be resistant to frost, as well as precipitation;
roofing material must endure temperature changes;
accumulated precipitation must be removed using a drainage system;
Sedimentary water must be removed from ordinary roof surfaces using a water storage and drainage system.

In addition, do not forget that:

drainage is provided by a certain angle of inclination of the roof;
the use of "filly" (special stuffing on the rafters, allowing you to create a slope more gentle) reduces the slope to the drainage system;
narrowing of gutters, dumbbells, channels or trays to the water drain is unacceptable;
the device of the channels of the cornices must be such as to provide reliable protection of the building from ice, snow, ice, icicles;
material for drainage gutters should provide elasticity at low temperatures and rigidity of drainage systems.

According to the regulations, the creation of an unorganized drain is quite acceptable. However, even on outbuildings, an organized drain will be more appropriate. Therefore, is it worth the risk of reducing the life of the house and creating problems for yourself in the future with its maintenance. An organized drainage system can save you from many possible troubles.

What does an unfinished drain look like?

An unorganized drain has a negative effect on the walls of the facade, accelerating their destruction. Therefore, in the process of their construction, an additional layer of waterproofing is required.
Even in areas where there is a minimum amount of precipitation, water will penetrate into the foundation, worsening its condition and slowly destroying it. To avoid this, additional drainage underground should be arranged to remove excess moisture.
Precipitation will also have an impact on the plinth. This indicates the need for periodic renewal of the waterproofing layer.

Requirements and regulations

under the slope there should be no footpaths, a roadway and balconies;
the peak of the roof should be equal to 60 cm or exceed these parameters in order to protect the building from moisture;
additional protection should be provided by a visor installed above the entrance.

Today, too stringent requirements are imposed on the design of buildings. However, caring owners, in order to increase the life of their houses, install a drainage system.

Type of drains

Drainage systems are of two types.

Outdoor, located on the outer sides of the building.

On roofs made of metal tiles, sheet steel, asbestos-cement sheets, corrugated board and small-piece materials, an external drain is provided.

The main requirements for drainage systems look something like this:

In addition, do not forget that:

drainage is provided by a certain angle of inclination of the roof;
the use of "filly" (special stuffing on the rafters, allowing you to create a slope more gentle) reduces the slope to the drainage system;
narrowing of gutters, dumbbells, channels or trays to the water drain is unacceptable;
the device of the channels of the cornices must be such as to provide reliable protection of the building from ice, snow, ice, icicles;
material for drainage gutters should provide elasticity at low temperatures and rigidity of drainage systems.

For any pitched roof, the presence of a drainage system is an indispensable element of the design. Its purpose is the collection and organized or unorganized removal of precipitation. Naturally, a well-designed and mounted organized outdoor drain has a number of advantages over an unorganized one.

Unorganized drainage systems

For structures of an unorganized type, an external drain implies a characteristic runoff of water along the entire perimeter of the lower slope, which increases the risk of destruction of the facade elements, the basement, and subsequently can lead to the destruction of the foundation base.

Such a solution is not considered the best, and therefore, even earlier, when gutters were made in a handicraft way, they tried to combine horizontal gutters with vertical pipes in their device or mount them at an angle towards one of the corners of the house.

In order to divert water from the walls of the house, it is necessary to take out the gutter at least 600 mm from the edge of the roof.

Organized outdoor drainage systems and their features

The device of an external drain of an organized type is a complex of elements for the removal of precipitation from the roof to the places intended for this. Such designs must include:

horizontal wall or hanging gutters;
vertical (storm) pipes and drains;
connecting elements;
elements of wall and roof fastening.

In addition to the method of organization, it is customary to distinguish outdoor drainage systems according to the following basic criteria:

material for manufacturing;
section of gutters and pipes;
form of the resulting structure.

Classification of drainage systems by material

By type of material, drainage systems are:

metal;
plastic.

In the manufacture of metal gutters, hot-dip galvanized steel is most often used. For additional protection of the material, the structural elements are coated on both sides with polymeric compounds (pural, plastisol). Steel structures have excellent performance. They are characterized by:

long service life,
increased strength,
improved resistance to adverse mechanical and chemical external influences.
resistance to corrosion and deformation from high and low temperatures.

An outdoor gutter system made of metal will best serve in areas that are characterized by a large amount of precipitation in the form of snow with its periodic descent from the roof.

Gutter systems made of copper coated with special varnish compositions that prevent its darkening are rightfully considered the most reliable and have the longest service life. It is natural that their cost is somewhat higher than other materials. At the same time, the aesthetic characteristics are much more attractive, and the appearance can fit almost any roof design.

For the manufacture of plastic gutters, PVC of increased strength is used. This is a lightweight and at the same time durable material that is not subject to deformation and corrosion, and does not require special care. The use of plastic drainage systems most often finds a place in the installation of soft roofing.

Classification of drainage systems by shape and section

The diameter of the pipes, depending on the required throughput of the drain from different manufacturers, can be in the range of 50-160 mm. For gutters, these values can be 70-200 mm.

When you are installing a drainage system on your roof, you will need to know parameters such as

total roof area;
tilt angle;
number of water outlets.

In general, the shape of the future system will depend entirely on the shape of the roof for which it is mounted.

How to mount a drainage system with your own hands

Installation of each of the drainage systems presented in this short review can be done independently. For this you will need:

tool;
drainage system;
manufacturer's assembly instructions.

When buying complex systems from branded manufacturers, each external drain, as a rule, must be accompanied by instructions for its installation with assembly flow diagrams. Different systems may differ in the method of connecting structural elements, the device for attaching them to walls and roofs.

Produced in the order specified by the instructions, from top to bottom. Here is the sequence of basic operations that will need to be performed:

Fix special fasteners and clamps on the roof and walls.
Fasten horizontal gutters with elements for connection to storm pipes on the mounts.
Install the required vertical and corner connection modules and end caps.
Install storm pipes in clamps with the possibility of their free movement.
Connect the vertical structural elements with the horizontal ones and fix them in the fixtures.

In conclusion, it remains to be added that a well-chosen outdoor drainage system for your home serves not only for practical purposes, but also perfectly complements and favorably emphasizes the features of its design.

The popularity of flat roofs today is rapidly gaining momentum. It is not only very beautiful, but also practical. This roof option can be a great solution for acquiring additional footage, as it can be used to organize a recreation area, a garden, and much more.

Scheme of water drainage from a flat roof.

This architectural solution used to be not so common in Russia, but now flat roofs are far from uncommon. They are perfect not only for covering outbuildings or garages, but also for residential premises. Such roofs have many advantages, but it is worth noting that the issue of water drainage from flat roofs is the main condition for their proper functioning.

Drainage device

It is important to remember that the slope of flat roofs is on the order of 2-5%, so in most cases, rainwater drainage is not a problem. However, in order to avoid trouble in the event of heavy rainfall and to ensure that the roof is always dry, it is necessary to think about a drainage system.

An important point is the waterproofing of flat roofs, which is not a complicated process, but it is necessary. In order to fulfill it in accordance with all the rules, it is worth deciding what materials may be needed. Their choice is not particularly large and includes polymer-bitumen or membrane materials. It is worth noting that when choosing materials, it is important to pay attention to their service life. If the calculation is for decades, then it would be advisable to use membrane ones.

Water drainage methods

Returning to the issue of drainage from a flat roof, it is worth emphasizing the main methods. The problem of water drainage from flat roofs can be solved both by traditional methods and by new, modern systems.

In the first case, we are talking about a drain, the installation of which is carried out on a special ledge or directly on the lowest roof overhangs located. If it is not possible to install gutters on any edges of the roof, then special enclosing walls are installed, the junctions of which with the roof covering must be protected by galvanization. The main function of these walls is to protect the wall from water runoff.

It makes sense to talk about installing a drain on a ledge, which is located lower than the roof overhang, if it is provided for by the design. In such a case, the best solution would be rectangular downpipes and gutters, which should be fixed with vertical brackets.

Drainage from a flat roof.

Installation of the drain on the roof overhang is carried out in special recessed channels. In this case, it is possible to use gutters independently made of galvanized metal or ready-made - steel or PVC. The drainage of water from the roof is carried out by sewers, which are carried out through holes in the channels with installed gutters.

A much better solution would be to provide for the drainage of water from flat roofs in more modern and progressive ways, which include siphon-vacuum and gravity.

In the first case, the system operates on the principle of water suction from the roof surface. The principle of operation is that the device located in the roof funnel does not allow air to enter the system, creating a vacuum effect - thus only water gets there.

This system has a number of advantages, among which are the effective patency of drainage channels, fewer sewers and their smaller diameter, as well as high funnel performance. However, there are also disadvantages, which are the complexity of installation and design.

The second system is much easier to operate, so it has been in demand for a large number of years. It is impossible not to take into account the fact that even if there is an error during the installation process, the drainage system will function correctly.

The principle of operation of the gravity system is that, falling into the funnel, rainwater continues to be discharged through the sewers, which are installed at an angle, in the direction where it was intended. Since water enters together with air, the diameter of the pipes should not be small. It should be the same throughout. The most preferred option is if the waste pipe is made of polymer and has a rounded shape.

Basic principles of water drainage

Summing up, it is worth paying attention to the basic principles and concepts of water drainage from flat roofs. The main elements are the roof funnels themselves, which already direct water into the sewers, from where it is discharged into the sewer, the ground or special containers provided for this purpose. Pipes, in turn, can be outside the building or inside.

To carry out a trouble-free process of water outflow, it is necessary to place the funnel at the lowest point of the roof, not forgetting the slope, the minimum of which should be within 3%.

There should be several funnels, in case of blockage of the main one, and they should all be connected to one pipe. It is worth installing them every 25 meters, not forgetting about the emergency ebb, in case the main system cannot cope with excessive amounts of water.

They should be selected depending on the design and purpose of the roof, as well as the level of insulation.

It is important to decide on the question of whether the sewers will be outside or inside. It is preferable to give the choice to external pipes, since they are easier to maintain, given that they are easy to clean or repair. The only drawback can be called an aesthetic moment. However, the appearance of the pipes does not spoil the appearance of the building so much.

Pipes that are installed indoors have much more disadvantages. Access to them is difficult, and in the event of a leak, the appearance of a fungus is inevitable.

It is worth considering freezing in sections of the drainage system, which can lead to blockage of pipes. To avoid this, heated funnels can be installed.

Given all the above nuances, a flat roof can not only please with an unusual appearance, perform additional functions, but also remain dry all year round, regardless of the amount of precipitation in any weather!

Flat roof drainage: dry roof all year round

Draining water from a flat roof is not as complicated as it might seem at first glance. A flat roof can stay dry all year round if you take into account all the necessary nuances.

What kind of drainage from a flat roof is better to do - types and features of the device

Equipping a flat roof, it is necessary to think in advance about how water will be drained from it. Unlike roofs with steep slopes, from which water flows off on its own, gently sloping structures always have problems with this. The water remaining on the surface of the roof is not particularly dangerous (of course, if the roof was assembled with high quality), but when it freezes, the likelihood of damage to the coating increases many times over.

To avoid the harmful effects of moisture on the roof, it is necessary to provide for high-quality drainage. About how to make a drainage system from a flat roof, and will be discussed in this article.

There are two main types of drainage systems:

Traditional drainage systems

If it is impossible to provide an organized drainage of water from some sides of the roof, it must be prevented from draining in order to protect the walls of the building. For these purposes, barrier walls made of concrete or metal are used. Galvanized "aprons" are installed at the junctions of these walls and roofing.

Drainage from a flat roof is installed in the following places:

On roof overhangs located lower than others;
On special occasions.

Using the first scheme, the drainage system must be fixed near the overhang in the prepared channels. As these channels, ready-made structures made of metal or plastic, or home-made elements made of galvanized steel, can be used. Drainage from a flat roof is carried out by means of drain pipes located in channels connected to the gutters.

In the case of a ledge, a flat roof with an external drain will be laid differently. As a rule, rectangular gutters and pipes fixed on vertical holders are used here for arranging drainage. In order for the drain pipes to be attached to the gutters, the required number of holes must be made in advance in the ledge.

However, a much more efficient design option is a flat roof with an internal drain. In order for such a system to work, the roof with a minimum slope of 2 degrees is divided into sections. For one such plot of about 150-200 sq.m. a separate stand is required. If the total roof area is less than the indicated values, then a single riser will be sufficient for drainage.

At points with a slope, external drain funnels for flat roofs are installed, equipped with dirt traps. Given that the drain is internal, these funnels are most often located near the center of the roof, and drain pipes are brought into the building and connected, for example, to the sewer system. To prevent freezing of the liquid near the funnels, it will not be superfluous to bring a heating cable to these areas. The internal elements of the drainage system must be heated constantly along their entire length.

Modern flat roof drainage systems

The main element of the external drainage system is a funnel that collects all the water into pipes (they can be located not only outside, but also inside the building) and forwards them to the sewer. The funnel is usually installed at the lowest point of the roof.

Often, drain funnels become clogged, resulting in a significant reduction in the efficiency of the catchment. To avoid this, it is worth installing several backup funnels that are connected to the main drain pipe. For maximum efficiency and the possibility of water discharge in case of flooding of the roof, a flat roof with an internal drain is equipped with an emergency outflow.

Different types of funnels are used for different types of flat roofs:

On roofs used as terraces, models with flat covers are installed - they do not interfere with movement on the roof surface;
For green roofs, funnels with nets are used to prevent various debris from entering the drainage system;
Insulated and non-insulated roofs are also equipped with their own types of funnels.

Indoor and outdoor gravity drain

Gravitational internal drainage is quite simple and may well work even if errors were made during installation. The principle of operation of this design is also very simple: the liquid collected by the funnel is sent through pipes outside the building. In this type of system, water passes through the system along with air, so large diameter pipes are required for its operation.

As a rule, plastic round products are used for gravity systems, which, in addition to high throughput, practically do not clog due to the smooth inner surface. Pipes are laid in non-residential premises and send water to where it will not bother anyone.

Siphon-vacuum drainage system

Such a system draws water into itself, and the drain funnel is equipped with a special element that prevents air from entering the drain. Due to the resulting vacuum, liquid is sucked into the drainage system.

Among the advantages of such a system are:

High funnel efficiency;
Possibility of using pipes of small diameter;
No need to lay long pipelines;
Good throughput;
Ability to operate the system even in the absence of a slope.

The elements and arrangement of the internal drain of the siphon-vacuum type are quite complex, therefore such a system is rarely used in private construction.

Classification of drain funnels

Drain fittings have several parameters, depending on which different types of these devices are distinguished:

Design. Structurally, funnels can consist of one or two parts. More complex fittings are typically used on roofs that can change shape, such as wood or non-ventilated roofs. Parts of the funnel in this case simply move relative to each other, so the drainage system continues to work with the same efficiency.
Bandwidth. This indicator is mainly affected by the diameter of the funnel. The throughput is determined by the volume of liquid that can pass through the funnel per unit of time.
Connection with waterproofing. Gutters can be connected to the waterproofing layer in different ways. One of the most popular methods requires a special crimp seam. Aprons made of film or roofing material are also often used. However, it is best to use fittings without aprons - they are suitable for roofs of any material.

High-quality drainage from a flat roof is very important. The gutter system, regardless of its type and design features, significantly extends the life of the roof, and hence the entire building.

Flat roof drainage: internal drain, external drain funnels for flat roofs, arrangement of drainage elements, drain

Flat roof drain: the specifics of the construction of internal and external options

Without a competent organization of the gutter system, a flat roof will quickly require unscheduled repairs. Stagnation of rain and melt water on the surface will gradually wash away the protective outer layer of the coating. As a result, the bare base will begin to rapidly collapse from the zealously attacking sun rays. When frozen, water crystals will easily break the material. A properly constructed flat roof drain can prevent and prevent negative impacts. The rules and principles for arranging such an important drainage system should be carefully studied by the owner, who cares about the efficient and long service life of suburban property.

Flat roof gutters

The purpose of the construction of a flat roof drainage system is to fully organize the drainage of rain and melt water from a surface that is sensitive to their action. It must operate effectively all year round without the formation of dusty blockages, ice and leaf plugs.

Regardless of the thermometer readings and the amount of precipitation, the drain must accept and promptly convey the liquid substance to the sewer, to a rainwater collection tank or simply to the ground.

Classification of rainfall systems

In order for water to be transported without interference and obstacles, you should know exactly what type of system to choose for arranging country property:

outdoor disorganized. Assuming spontaneous runoff of atmospheric water. They are used for arranging small outbuildings with a height of no more than two floors.
outdoor organized. Assuming the collection of water using gutters or gutters, coupled with funnels, with subsequent transfer to the drainpipe. The system is laid along the cornice overhangs and the outer side of the load-bearing walls. It is used in the arrangement of residential and non-residential buildings, mostly low-rise, but the scheme is acceptable for organizing runoff from the roofs of houses up to five floors high.
Interior. According to this, water intake is carried out by gutter funnels designed specifically for flat roofs, mounted in the roofing system. Water is drained through risers located inside the treated building.

Outdoor gutter systems work great in the southern regions, where the water in the pipes rarely freezes or does not freeze at all during the entire cold period. For areas of the domestic temperate climatic zone, external drains are recommended exclusively for attic structures.

On roofs without an attic, the snow will melt almost without interruption all winter, because the ceiling is constantly heated by the heat coming from inside. Getting into cold pipelines, melt water will form ice jams.

If a flat roof has an attic, then the snowmelt process can be regulated. By opening the dormer windows, the temperature on the roof can be significantly reduced, due to which the snow will melt much more slowly or completely stop.

In the northern regions, there is a threat of rupture of the coating during a sharp cold snap. A plug may form in the pipes, preventing the flow of water remaining on the roof. The crystallizing liquid significantly increases in volume, which leads to damage to the roof that has absorbed it. Therefore, in the northern and temperate domestic latitudes, only non-residential ones are equipped with external drains, i.e. unheated buildings and buildings with a projected low temperature.

Cold storage facilities, for example, are equipped with a remote reinforced concrete slab with a side and a drain riser. The impressive area of \u200b\u200bsuch a structure helps to equalize the temperatures of the system and the environment, so that ice plugs do not form.

Residential houses with flat roofs, built in the regions of the northern and temperate zones, are equipped with internal-type drains. The construction is more expensive, but works flawlessly all year round. The risers located inside the buildings are constantly heated by internal heat, which prevents the occurrence of ice jams in the pipelines. In the southern latitudes, drains of the outer variety are in the lead.

Structural components of gutters

In the device of gutters of external and internal type there is a lot in common. Each system built for flat roofs includes elements similar in purpose and design, these are:

Drainage funnels and gutters designed to receive wastewater and transfer them to the drainpipe.
Risers, providing at the points of reception the maximum speed of the water flow due to the forces of gravity.
Drainpipes required for the removal of atmospheric precipitation to the unloading facilities.

The main guideline for designing a drainage system is the minimum length of the main line from the points of water intake to the points of discharge of the system. The shortest and cheapest outdoor option includes a riser with a funnel or gutter at the top and a short outlet at the bottom.

The outlet is located at a slight angle at a distance of 20 - 45 cm from the surface above the storm sewer or simply above the blind area protected from erosion. However, insurmountable circumstances often interfere with equipping a house with a drain of such a scheme: lack of a drainage system, weak soils, an old foundation, the proximity of which is undesirable to water.

If it is impossible to lay the smallest highway, they look for other ways to drain water: a ground or underground pipeline leading to the most convenient place of unloading is diverted from the riser.

The pipeline scheme is unconditionally used in the construction of flat roofs with an internal drain, because the system is definitely obliged to transport water outside the building.

The specifics of the slope formation

To stimulate an independent flow of water in the required direction, slopes of 1-2% are formed on flat roofs:

To organize an external type of drain, the entire plane must be inclined towards the installation site of the gutter. Most often this is the back wall of the building.
To organize the flow of water according to the internal scheme, a slope is created to the installation site of the water intake funnel. It is formed according to the envelope principle so that around each water intake point there is a decrease in a radius of 50 cm.

Inlet funnels of internal drainage systems can be installed not only in the central area of the roof, but also near the outer wall, at a distance of at least 60 cm from it. Therefore, the envelope scheme of the tilt device has quite a lot of different options.

In any case, the inclined plane should be directed towards the water intake. And if several funnels are installed on the roof, a kind of “watershed” should be created between them - a miniature likeness of a mountain range, the slopes of which direct the flow of water in the direction of the nearest funnel.

To solve the problem of forming slopes, there are several proven methods in practice:

Tilt device during construction by setting the ceiling at the required angle.
Backfilling of expanded clay in the form of a wedge-shaped layer, followed by pouring a cement-sand screed.
Organization of the slope by laying wedge-shaped plates of mineral wool insulation.

The slope of large-sized planes is carried out using special, angle-forming metal structures. They are rarely used in private construction.

Rules for the construction of an internal drain

As it should be for any facility under construction, the drainage system of a private house must be calculated and designed in advance. It is necessary to choose in advance the shortest possible route for laying the pipeline and provide for the most convenient place for connecting it to the storm sewer.

A variety of flat roof structures are subject to the organization of internal drains. They are arranged on roofs with and without attics, operated and non-operated category. Taking into account the planning specifics of the house, an independent designer needs to take into account that:

Gutter risers are usually located in the area of stairwells near walls, columns, partitions. Preferably near living quarters for spontaneous heating during cold periods of the year. Embedding risers into walls is strictly prohibited. Can be installed in gates, shafts, boxes. It is recommended to place them in closets or similar auxiliary compartments.
When organizing a drainage system for an unheated building, it is necessary to provide for methods of artificial heating of funnels and risers. To increase the temperature of the external elements of a flat roof, install an electric heating cable or mount risers next to the steam heating.
A flat roof with an attic is best equipped with piping that runs within the attic space. It is carried out in the form of a suspended network. To ensure the flow, the horizontal sections of the pipes of the suspension system are installed at an inclination of 0.005. Those. for each linear meter of the pipe there should be a 5 mm drop in the direction of the spillway.
When laying overhead pipelines, the drainage area in the attic area must be insulated.
If the installation of a suspension system is not possible, an underground pipeline is laid. There are no regulations on the angle of inclination of underground branches. The main thing is to be connected to the storm sewer. True, the underground scheme is much more expensive, much more inconvenient in terms of control and repair work. In addition, its implementation may be hindered by a too powerful foundation.
When designing, bends should be avoided whenever possible.
A riser at a distance of about a meter from the surface of the earth should be equipped with a revision for cleaning.

In fact, a drain from a flat roof should be organized like a standard weir system: with manholes, revisions, etc. In the construction of a suspended drainpipe, ceramic, plastic, cast iron, asbestos-cement pipes are used that can withstand pressure in case of blockages.

For laying underground parts of the pipe from the same materials, but without requirements for hydrostatic conditions. Steel long pipes are used only at production facilities with characteristic manifestations of vibration.

According to technological requirements, one catchment funnel can receive atmospheric runoff from a roof with an area of up to 1200 m², the distance between adjacent water intakes must be at least 60 m. Agree, the indicated scale for low-rise construction is not very typical. In short, there should be at least one funnel on the roof of a small private house.

An increase in the number of water intakes will be required if:

The roof area exceeds the limits specified by GOST.
The house is divided into sections. Then each compartment should be equipped with its own funnel.
Within the same roof structure, there are elements separated by parapets, expansion or expansion joints. Each sector of such a roof should have two water inlets.

Drainage funnels are produced for operated and non-operated flat roofs, for combined structures and systems with attic space. There are models used in the arrangement of concrete floors with bitumen coating and wooden counterparts covered with corrugated board. For all options used in construction, water inlets are made of cast iron, ceramics, galvanized steel, and polymers.

Water inlets are manufactured in a variety of sizes. The standard design consists of the funnel itself with wide sides and a removable cap with holes that provide water flow.

More complex representatives of the class of roof funnels are equipped in addition with an umbrella that protects the drain from clogging, a removable glass and a clamping ring designed to clamp the edges of the soft cover in the device. All models must be serviceable and cleanable.

Regardless of the model of the funnel and the purpose of the building, equal requirements are imposed on all water inlets:

The bowls of the water collectors are rigidly attached to the coverings or load-bearing decks. For fixing, clamps are used in an amount of at least two pieces.
After installation, the funnel must ensure the tightness of the roof at the installation site.
The pipes of the funnels are connected to the risers with the help of compensators, which make it possible to maintain the tightness of the joints during shrinkage of building structures.
Funnels are connected to suspension systems with shaped bends.
The water intake bowl is installed below the level of the finishing roof to eliminate the possibility of stagnant water. Caps of water inlets on non-exploited roofs have a rounded shape in plan, they usually rise above the coating. Funnel caps for serviceable roofs are installed flush with the coating, they are most often square in plan, so that it is easier to lay tiles around the device.

To increase the sealing and reliability in the area of intersection of the funnel roof structure, the use of thermal insulation is allowed. Roofing systems of the usual type are equipped with single-level funnels.

Inversion systems and roofs constructed using mechanical fasteners are equipped with two-level water inlets that collect water above the waterproofing and above the vapor barrier.

It is customary to equip roof structures with a polymer membrane coating with water inlets with a polymer clamping flange, which is glued or welded to the roof.

This method achieves the maximum possible waterproofing in the area of \u200b\u200binstallation of the water intake device. The areas for gluing the flanges of water intakes must be reinforced with additional layers of waterproofing deposited material. You can replace it with fiberglass glued to the mastic.

Construction of an external drain

The construction of external varieties of drains from a flat roof is carried out in the southern regions. Their installation in residential and office buildings is recommended in areas with low precipitation, the volume of which does not exceed 300 mm per year.

The class of external drainage systems for rain and melt water includes:

Unorganized drains recommended for installation in dry areas. According to this scheme, water is discharged by gravity along the cornice overhangs.
Organized drainage, recommended for equipping non-residential buildings in the northern and temperate latitudes, residential buildings in the southern regions with little rainfall. The principle of operation consists in the systematic collection of precipitation into an external drain funnel with guide edges adjoining it or into a gutter, followed by drainage into a storm sewer or into the ground.

An ingenious solution for an outdoor type system was proposed by diligent craftsmen. The idea is to include a sand filter in the water supply network to purify rainwater, which is installed after the water intake.

Containers were installed to unload the drain and receive purified water. This means that the site for connecting the system to the sewer is abolished. An interesting scheme allows you to profitably solve two problems at once: to get water of drinking quality and to protect a flat roof from water stagnation.

An unorganized type of drainage system requires reinforcement of cornice overhangs. They must be upholstered with galvanized roofing steel, and then glued on top with two layers of rolled roofing. Additional layers are laid with an overlap.

Strengthening the overhang of a mastic flat roof is strengthened by analogy. Only instead of glued layers of bitumen or bitumen-polymer material, layers of mastic are applied, alternating them with reinforcing layers of fiberglass or geotextile. The main layer of reinforcement with reinforcement must overlap the edge of the metal upholstery of the eaves.

Fixing the external drain on the eaves of a flat roof is carried out according to the traditional scheme. On sale are a lot of ready-made kits with detailed instructions for assembling systems. First, brackets are attached to the frontal board, into which a chute assembled from plastic or metal modules simply fits.

In a place convenient for further transportation of water, a gutter funnel with a branch pipe is installed, to which the riser is connected. The pipe is fixed on the wall with brackets. The edges of the system are closed with plugs, and completed with the installation of a curly outlet.

Flat roof drain: external and internal device methods

In order for a flat roof drain to work efficiently and smoothly, you need to know how it works, choose an external or internal system to drain precipitation from the roof.

Characteristics of the types of organized drainage from the roof. Their differences, advantages and disadvantages

A properly selected water drainage system is the key to a long roof life. Since there is no slope at the flat roof, it is easily susceptible to the negative effects of precipitation, which remain on the surface and, when frozen, destroy the roofing material, and before that - the protective layer of the coating. To prevent such consequences, it is necessary to correctly select and install a water flow system. Any owner of a private house should know the structure of the drainage structure.

Buildings with a flat roof, no more than 2 floors high, may have an unorganized drain from the roof. If the structure is higher, it becomes necessary to install an organized drain (internal or external). That is, on multi-storey buildings with a flat roof, it is necessary to install a structure for the removal of melt and rainwater.

External and internal drainage

To prevent the negative impact of precipitation on the walls of buildings with flat roofs, special barrier walls with a concrete or metal coating are installed. The joints on the walls are covered with a galvanized apron. Install a water drainage system on overhangs below the rest of the surface or specially designed performances.

In the external drainage system, funnels are installed near the roof overhangs. Then the sedimentary water goes through the sewers, which are drawn through the holes in the channels, where there are special gutters. The internal organized drainage system provides for the installation of funnels directly on the roof surface. Water flows down the channels located inside the house.

How does a flat roof gutter work?

For a flat roof, a special type of external and internal drainage systems are made.

A flat roof with an internal drain has a more complex structure than an external drain from the roof. However, the first system has more advantages, as a result of which the owners of country houses prefer it. You can draw a comparison with how the drain in the bathroom is arranged, where there is some water left. When the drain is opened, this water will go down the drain. According to the same principle, an internal drain on a flat roof is arranged. It is possible to make such a design that melt and rainwater flow not into the sewer riser, but into a special container. This water can then be used for your own purposes.

Advantages and disadvantages of internal drainage

The advantages include its following properties:

Neat appearance. You can not worry about whether the design will successfully combine with the exterior of the house or building.
Since the pipes are located inside and not outside the building, they are protected from changes in air temperature. So the owners of the house should not worry about the condition of the pipes.
The internal gutter of the roof, when properly installed, does its job best.

However, this type of drainage also has some disadvantages. Among them:

Difficult cleaning process.
The need to design a house, taking into account the installation of an internal drain. In any case, even before the roofing work begins, such a drainage system must be included in the project. Otherwise, you will have to dismantle the roof.

Types of internal drainage structures and materials for their manufacture

There are two types of internal drainage systems:

To find out which system is better to install for a building with a flat roof, it is necessary to make an approximate calculation of the drain.

In systems of the first type, sedimentary water is extracted by gravity. Such a system is ideal for country houses and oversized buildings with a small roof area.

To install the second system, special funnels are required for the outflow of water. If there is little sedimentary water, then such a system functions on the same principle as the gravitational one. With a large volume of water in pipes and funnels, it is drawn into the general sewer or wastewater tank due to the draft that appears in the system. This design of an organized drain from the roof is applicable to large-sized buildings that have a large roof area.

They are usually made of metal or plastic. This material is characterized by light weight, it is easy to work with it, while it is strong enough if the pipes have stiffeners. However, in harsh climates, plastic parts can quickly fail due to changes in air temperature. Metal systems are more durable and reliable. The most resistant and aesthetic metal is copper. But the price of such structures is quite high. Structures that consist of other metals usually have an anti-corrosion coating, which allows you to extend the life of the gutter system.

Specifics of the project and installation of an internal drain

An important point during installation is the roof slope. It is made 50 centimeters from the funnel where the water will flow, the exposure level is 5%. Further, it is equally important to correctly calculate the required number of funnels. Their number depends on their diameter and roof area. A funnel with a radius of 10 centimeters can collect water from a roof with an area of 240 square meters, and a funnel with a radius of 0.7 centimeters can collect water from a roof with an area of 110 square meters. Be sure to install at least 2 funnels. This is done for safety reasons, in case one of the funnels becomes clogged or fails.

In regions with a cold climate, there is an increased risk of freezing parts of the water drainage system. The roof and gutter heating system prevents this problem by installing a heating cable in the system. Specially designed nozzles prevent clogging of drainage systems with debris and leaves.

For each case, the size of the pipes is individually determined, taking into account the amount of precipitation, the degree of temperature difference during the day, the number of verticals in the structure. Storm drains should be installed at a distance of at least 50 centimeters from each other. It is recommended to mount water drains in such a way that they can collect water from equally sized parts of the roof. Near the funnels, it is necessary to more effectively seal the holes or install another layer of waterproofing.

To install a drainage system, it is necessary to make an exact plan of a flat roof, the parameters of which are individual in all cases. It is also important to take into account the specifics of the climate, the amount and quality of precipitation and the difference in air temperature.

Drainage structures of the external type

These systems are recommended to be installed in houses in the southern regions, where there is little rainfall (no more than 300 mm per year), since the water in the pipes does not freeze there or this happens extremely rarely, so the anti-icing system for the roof and gutters is simply not needed here. For regions with a temperate continental climate, it is possible to install such systems only in the attic. On non-attic roofs during the entire winter period, the snow will constantly melt due to the continuous heating of warm air from inside the house. Further, water flowing into cold pipes will lead to ice jams.

There is an unorganized and organized external drain from a flat roof.

The second type is suitable for buildings in the northern region with a temperate continental climate. Water is collected in such structures in an external funnel, to which the sides are attached, or in a special gutter. Further, the water flows into the ground or into the storm sewer.

The design of an unorganized external drain is characterized by stronger cornice overhangs. They are upholstered with special steel for roofing, coated with zinc. Next, they are covered with a roofing coating in two layers.

This type of drain is installed as follows: brackets are attached to the front board, where the supply channel and a special container (made of metal or plastic) are placed. There, where the precipitation will flow, they put a special funnel to receive water. Behind it is a branch pipe to which a riser is adjusted. Brackets mount the pipe on the wall. At the edges, the structure is covered with plugs, then a figured outlet is placed.

Thus, competent installation and proper maintenance of the drainage system will ensure efficient and complete collection of melt and rainwater for a long time. To do this, you will need to first draw up a drainage plan, you must also take into account the type of building (residential or non-residential premises) and the climatic features of the region.

Characteristics of the types of organized drainage from the roof

Organization of water drainage from the roof. Execution options internal and external drain. Their pros and cons, as well as mounting options

6. Roofing.

Organization of a drain on the roof. Questions and answers.

The main reason for the formation of icicles and ice on the roof of the building is the lack of ways for the melt water to drain. What other factors cause the formation of ice on the roof?

The main factor in the formation of ice and icicles on the roof is an improperly organized drain. Other factors contributing to the formation of ice:

Atmospheric heat - daily difference in air temperature, solar radiation;

Own heat dissipation of the roof, which is facilitated by:

Insufficiently effective heat and vapor barrier (when using under-roof space for living). To protect the heat-insulating layer and the base under the roof from moisture penetrating from the room, a vapor barrier should be provided in accordance with the calculation.

All types of household activities are accompanied by a significant release of water vapor, the penetration of which into the roof structure occurs under the influence of steam pressure and air movement. Even if the vapor barrier in the roof structure is carefully made, moisture still penetrates into the insulation through leaks around communications, material joints, etc. Moisture condenses in the insulation, due to which its thermal insulation ability decreases sharply. The most important quality of a vapor barrier is its continuity;

Lack of under-roof ventilation: ventilated attics (if the attic space is not used for living) and air vents or an air gap between thermal insulation and roofing (when using the attic space for living). The most rational method of removing moisture is the presence of an air gap between the thermal insulation and the roofing for ventilation of the under-roof space. A continuous ventilation slot is provided in the cornices, and a ventilation opening is provided in the ridge or pediment. Traditionally, when installing thermal insulation in a structure, two ventilation gaps are left, forming two ventilation zones - upper and lower. Through the lower ventilation gap, located between the waterproofing coating and the insulation, condensate from the air coming from inside the room is removed. And through the upper ventilation gap, which is formed between the roof and the waterproofing, moisture that gets inside from the street is removed. With the modern method of insulation, vapor-permeable (diffusion) membranes are used as waterproofing. Ventilation is carried out through one ventilation gap between the roof and the diffusion film through which condensate from the room passes.

SNiP 11-26-76, paragraphs 4, 5; SNiP 23-02-2003, p. 9

How to ventilate the under-roof and attic space to minimize the increasethermal insulation and condensation on the inner surface of the roof?

For ventilation of the attic space, it is necessary to provide for supply and exhaust openings in the outer walls (in each wall with a total cross-sectional area of at least 1:500 of the coverage area) or a device in the covering of dormer windows. These holes must be closed with a mesh with cells no larger than 20 × 20 mm. The area of the supply and exhaust openings must not be less than the cross-sectional area of the ventilated layer. The height of the ventilated air gap above the thermal insulation is determined on the basis of a calculation and cannot be less than 50 mm. In non-ventilated coatings, it is not allowed to use wood and heat-insulating materials based on it. SNiP 11-26-76, p. 5

How to reduce the icing of the roof surface?

Icing occurs due to the increased impact of solar radiation on the roof, the lack of hydrophobic properties of the surface, as well as the intense adhesion of water, ice and dust to the roofing materials. To reduce the effect of these factors, it is necessary to use light-colored paint compositions with increased water-repellent properties.

On which roofs should internal and external drains be provided?

An internal organized drain should be provided on rolled and mastic roofs, an external organized drain - on roofs made of small-piece materials, asbestos-cement corrugated sheets, sheet steel, copper, metal tiles and metal corrugated board. Internal organized drainage and external unorganized drainage on roofs made of reinforced concrete tray panels can only be provided in buildings up to 10 m high. TSN KR-97 MO, clause 4.8 (SP 31-101-97 MO)

How to properly place water intake funnels on the roof?

Water intake funnels of the internal organized drain must be evenly spaced over the roof area. For 1 cm2 of the cross section of the funnel pipe, there is 0.75 m2 of roof area. On each section of the roof, limited by walls and expansion joints, there must be at least two funnels, and with a roof area of up to 700 m2, one funnel with a diameter of 100 mm can be installed. The bowls of water intake funnels should be located in the lowest places of the roof, no closer than 500 mm to the parapets and other protruding parts of the building. In places where funnels are installed, a local lowering of the roof of 15-20 mm within a radius of 0.5 m is provided. TSN KR-97 MO, clause 4.9; 4.10; 4.11 (SP 31-101-97 MO)

How to perform outdoor organized drainage?

When installing an external organized drainage system, the distance between downpipes should not exceed 24 m, and the cross-sectional area of \u200b\u200bthe pipe is taken at the rate of 1.5 cm2 per 1 m2 of roof area. Suspended and wall gutters must have a longitudinal slope of at least 2%. TSN KR-97 MO, clause 4.12 (SP 31-101-97 MO)

When and how is the operation of drains checked?

It happens in autumn. The work is carried out in order to timely carry out all operations to repair roofs and prepare them for winter.

On the roof plan, zones of stagnant water, the degree of contamination of the funnels are noted. With unorganized external drainage - places and degree of soaking of facade walls and plinths with water flowing from the roof, rainwater flowing through balconies into the rooms of the upper floor, and through pits - into the basement floors. It is also necessary to clean the water intakes from leaves, needles and dust (it is forbidden to sweep leaves and debris into drains). To clean the roofs, wooden shovels, brooms or polymer scrapers should be used.

How to eliminate stagnation and freezing of water at parapets, roof railings, architectural details,facing roofs with external drainage?

First of all, you need to find the reason. This is probably the placement of unnecessary architectural details on the roofs, vertical elements that prevent the flow of water.

It is necessary to redesign all elements of the roofing, including taking into account the possibility of installing an anti-icing system.

What is an anti-icing system and where is it used?

Anti-icing systems are used in places where it is necessary to prevent the formation of ice and icicles - on roofs, open terraces, porches, steps, ramps - and to prevent freezing and damage to pipelines (heating, water supply, sewerage, etc.). Anti-icing systems for open areas, steps, garage entrances allow their safe use in winter.

Most often, anti-icing systems are used to prevent the formation of frost on roofs. Even a properly executed drainage system does not always cope with the task of drainage. In winter and spring, this leads to the formation of ice and icicles on the roof. The snow on the roof thaws and flows to the colder edges, where it freezes again, forming an ever-growing icing. Gutter systems also freeze and cannot drain water that melts on the roof, damaging the roof and facade of the house. In most cases, it makes more sense to install an anti-icing system than to make permanent repairs. The basis of anti-icing systems is heating cables laid in places most prone to ice formation. Since the entire anti-icing system is energized during operation, its device must meet all the requirements of the PUE, SNiP 3.05.06-85 and SP 31-110-2003.

What are the typical heated areas of an anti-icing system?

Typical heated zones:

Downspouts for the entire length;

Gutters and trays;

Gutters and areas around them with an area of about 1 m2;

Knots for entering gutters into downpipes;

Valleys (junction lines of roof planes);

Other adjunctions to the roof plane (dormer windows, lanterns, attics);

Water cannons and water jet windows in the parapets;

Roof eaves; droppers;

Surfaces of flat roofs and concrete gutters;

Drainage and catchment trays in the ground under downpipes.

In what parts of the roof are anti-icing systems installed?

Heating cables must be installed on the horizontal parts of the roof and along the entire path of the melt water. In the presence of entrances to the storm sewer - up to the collectors below the freezing depth.

What are the requirements for anti-icing systems in terms of fire and electrical safety?

The system should include only those heating cables that have certificates of compliance and fire safety (as a rule, these are non-combustible cables or cables that do not support combustion);

The heating part of the system must be equipped with an RCD or a differential circuit breaker with a leakage current of not more than 30 mA (for electrical safety requirements - 10 mA);

Complex anti-icing systems must be divided into separate parts with leakage currents in each part not exceeding the above values.

PUE, SNiP 3.05.06-85, SP 31-110-2003, SNiP 21-01-97*

What technical components does the anti-icing system include?

The anti-icing system includes:

The heating part, consisting of heating cables and accessories for their installation on the roof. This part directly performs the task of turning snow or frost into water up to their complete removal. The composition of the heating part may include some snow retention elements that interact with the heating elements;

Distribution and information network that provides power to all elements of the heating part and conducts information signals from sensors to the control system panel. The system includes power and information cables that meet the conditions of work on the roof, junction boxes and fasteners;

A control system comprising:

Control cabinet;

Special thermostats;

Temperature, precipitation and water sensors;

Balancing and protective equipment corresponding to the capacity of the system.

How do anti-icing systems work with changes in outdoor temperatures?

The system must be equipped with temperature, precipitation and water sensors, as well as an appropriate specialized thermostat, which can be called a mini weather station. It should control the operation of the system and allow the possibility of adjusting the temperature parameters, taking into account the specific features of the climatic zone, the location of the building and the number of floors in it.

Are anti-icing systems designed to operate throughout the winter?

The operation of anti-icing systems at temperatures below -18 ... -20 ° C, as a rule, is not needed. Firstly, at such temperatures, ice formation does not occur and the amount of moisture decreases sharply. Secondly, under these conditions, the amount of precipitation in the form of snow also decreases. Thirdly, the melting of snow and the removal of moisture at such temperatures require significant electrical power. When designing and installing an anti-icing system, it must be borne in mind that the designer must ensure that the water that appears as a result of the operation of the system has a free path - up to complete removal from the roof and from gutters.

Are flat roofs heated?

It is recommended to heat flat roofs with armored resistive cables, based on a specific power of 250-350 W/m2, and higher powers refer to roofs that can have large drifts. The step of laying armored cables ranges from 100 to 140 mm. The minimum bending radius of the NBMK cable is 45 mm.

Parapets located along the edge of the roof act as guide gutters, but at the same time they contribute to the accumulation of snow and ice. To heat the roof behind the parapets, it is recommended to take the same power as for the gutters, but one step more.

Water cannons in parapets are very dangerous places that contribute to the accumulation of ice. It is recommended to heat the bottom of the water jet and the area in front of it at least 1 m2 based on a power of 300 W/m2.

When calculating the power and the required number of heating cables, one should proceed from the following recommendations:

- Water pipes. The rated power of heating cables installed in pipes, in the absence of water, ranges from 20 to 60 W per 1 linear meter. m. It depends on the length and diameter of the pipe. Especially effective is the use of self-regulating cables that can increase heat transfer in the presence of water by 1.6-1.8 times;

- Gutters and trays. Linear rated heating capacity of gutters depends on the catchment area lying above the gutters (trays), and can be normalized through the catchment area per 1 m of the gutters (flumes). With a catchment area of up to 5 m2, the heating power may not exceed 20 W/m, increasing to 50 W/m with a catchment area of 25 m2 or more;

- droppers(depending on the design of the dripper itself) are heated in one or two threads with a self-regulating or armored cable;

- cornices, located below the gutters, serve as a source of formation of snow and ice blocks that break off the roofs. To remove snow on the cornices, laying is carried out either along the cornice (with a width of the latter up to 300 mm), or over the entire area. In this case, both self-regulating and armored cables can be used;

- valleys also contribute to the accumulation of snow. They are recommended to be heated at least 1/3 of the length. As a rule, according to the layout of the heating sections, the heating of the valleys is usually combined with the heating of the gutters.

"Soft roof. Materials and technologies of works: Reference book "- M.: Stroyinform, 2007. -500 p.: ill. - (Series - "Builder").

ISBN 5-94418-032-3

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