How to heat roofs and gutters with an anti-icing system. Roof heating - technology Installation of a roof heating system

The cable heating system for roofs and gutters is an anti-icing system based on the use of electric heating cables to melt snow and ice on the roof and in the drainage system of the building during periods of danger - at a time when daily temperature fluctuations occur and ice formation is most likely.

In turn, it is ice that causes roof leaks in the autumn-spring period, as well as the cause of deformation of gutters and gutters due to ice and snow accumulated in them.

Since the roof anti-icing cable system does not allow the formation and, accordingly, the fall of icicles on the adjacent territory, it is classified as a security system.

It is quite natural that in 2004 a document of the Moscow Architecture Committee “Recommendations for the use of anti-icing devices on roofs with external and internal drains for residential and public buildings under construction and reconstruction” appeared, which directly recommends the installation of such systems on all new buildings.

Currently, several thousand buildings are equipped with cable roof heating systems in Moscow and St. Petersburg. Significant experience in design, installation and operation has been accumulated.

A properly designed and properly installed roof heating cable system based on high-quality components does not allow ice accumulation and ensures the removal of melt water along the entire route. As a result, the roof itself lasts longer, the gutters do not sag, the gutters do not deform, and people and cars in the vicinity of the building are not threatened by falling icicles.

Roof heating in photos

• Warm and cold roof heating

  • In the case of a cold roof (having minimal heat loss), it is enough to revise the drainage system and install heating cables in gutters and gutters.
  • In the case of a warm roof, it is very likely that installation will be required in other areas: valleys, drips (cornices), dormers, junctions and overhangs.
  • If the roof is completely iced over, then the installation of KSO may not be economically justified and the reconstruction of the roof suggests itself.

  System Composition

  The following classification seems to us the most successful:

  1. Subsystem of heating elements

  Heating cables for use on the roof are subject to increased requirements:

  • linear power: not less than 20 W/m and not more than 60 W/m at 0°С;
  • shell resistance to UV radiation;
  • resistance to local overheating;
  • reliable operation in wet conditions;
  • the presence of a shielding braid;
  • certification of compliance with TR TS 004/2011 "On the safety of low-voltage equipment";
  • certificate of conformity TR CU 012/2011 "On the safety of equipment for operation in explosive environments" * (if the building is located in an explosive zone, for example, a gas station).

  Roof and gutter heating systems use resistive cables and self-regulating cables.

  The advantages of resistive cables include low cost and stability of power characteristics. The disadvantages are the impossibility of changing the lengths of the sections and the likelihood of overheating. On soft (welded) roofing, resistive cables cannot be used.

  Resistive cables for roofing

Heating of roofs and gutters has become an integral part of the design of modern buildings. It is necessary to increase comfort and safety level by counteracting the icing of the functional elements of buildings. You can observe a clear confirmation of the validity of using such systems in the spring, when there is a massive melting of snow and ice from the roofs.

If the roof heating system is not installed, then this poses a potential threat to people's lives. They are at risk of serious injury from a mass of ice falling from a height. In addition, it becomes necessary to regularly repair the drainage system, which collapses both under the excess weight of the ice, and during the snow from the roof. All this can be avoided thanks to solutions that are quite simple from a technical point of view.

Equipped heating of the roof and gutters is guaranteed to prevent both an accident and regular damage to the drainage system. It effectively prevents the accumulation of snow masses and the formation of ice. Once you have made a decision and put it into practice, you will stop worrying about the safety of passers-by and vehicles, as well as maintaining the integrity and functionality of the drainage elements.

Roof anti-icing

Our company provides 100% protection of roofs and elements of drainage systems from ice and snow drifts. Roof anti-icing system consists of:

1. Heating cable sections. This is the main element. Cable laying is carried out with the formation of threads in an amount of 1 to 4. Installation of heating of the roof and gutters is performed on such elements: gutters, gutters, valleys, droppers, etc. One of two types of cable is used - self-regulating (preferable) and resistive.
2. Control cabinet. No less important part of the system than the cable for heating the roof. It is designed to house the electronic control components that are required for automatic capacity control. The kit also includes equipment for protection against short circuit, overload, current leakage. The protection category of control cabinets, as a rule, is not lower than IP67.
3. Fasteners and installation elements.
4. Power distribution system. This category of equipment includes cables and junction boxes.

Attention! The heating system of the roof and gutters must be activated before precipitation. If the moment is missed and a significant amount of snow has accumulated on the roof, then a full cleaning of the surface becomes impossible.

Saving

Professional installation is one of the conditions for reducing costs. If the anti-icing system for roofs and gutters was installed with violations of requirements, technologies or using low-quality materials, then the cost of its maintenance increases significantly. At the same time, after a competent installation, the need for seasonal maintenance is practically eliminated. It also reduces the risk of equipment failure. Our company not only guarantees high-quality installation, but also repairs of systems installed by other contractors.

Take care in advance

In the climatic conditions of our country, frost on the roofs is always formed. Heating the roof and gutters is the only way to prevent these natural processes. Do not delay with the decision before the onset of cold weather. Installation of the system, including for soft and flat roofs, before a cold snap is right. Spring and summer are cheaper.

A roof without icicles is:

• durable aesthetically attractive appearance of the building;
• minimal roof cleaning costs;
• safety for people and property;
• long service life of the drain and other structures.

Where do icicles come from

If the installation of heating of the roof and gutters is not completed, then the formation of icicles can be predicted with 100% probability, regardless of the type of roof, as well as the category of thermal insulation - cold or warm.

cold roof does not give off heat to the external environment, but the snow melts under the influence of the sun, and the water runs into the frozen drain.

Result: water freezes in the catchment system - icicles grow.

warm roof due to the lack of sufficient thermal insulation, it gives off heat to the external environment. Snow melts throughout the winter.

Result: water constantly runs into the drain without heating - icicles grow.

Solution

The best way out of the situation is a self-regulating cable for heating the roof and elements of the drainage system, which is characterized by the highest energy efficiency.

Installation work

The system is installed in problem areas using galvanized steel fasteners. The OBOGREV-MONTAZH company guarantees that the price of heating the roof and gutters will be the most acceptable, the quality and reliability will be high.

An example from our work:

Main equipment used

Heating cable:

We recommend using a self-regulating cable manufactured by SST

The effect of self-regulation of a self-regulating heating cable is based on the use of a special semiconductor matrix in it, which changes its conductive properties depending on the ambient temperature - with increasing temperature, the resistance of the matrix also increases, which means that the flowing current decreases, which in turn leads to a decrease in the generated thermal power. When the temperature decreases, the reverse process occurs. At the same time, each section of the self-regulating heating cable changes its properties depending on the specific temperature in a certain section, regardless of other sections. Therefore, a self-regulating heating cable cannot burn out even if it is overlapped.

Control equipment:

Heating cable for drains and roofs. Selection and installation in the anti-icing system.

During the period of rapid climate change, which occurs with the change of seasons, the normal functioning of the drainage system is most at risk. Icing of pipes and gutter occurs quickly, and therefore the formation of ice plugs is possible. This will significantly slow down the operation of the drainage system, or even block it altogether.

In addition, there is a risk of rupture and collapse of the drain, due to an increase in its mass due to frozen ice. With anti-icing systems, the above cases can be avoided. a fundamental part of the component of such a system will fall.

Heating cable functions :
It is a current conductor that can convert electrical energy into heat. And the heat generated by the cable will depend on the strength of the current and the resistance of the conductive material. From the school curriculum, we must remember that this feature is characteristic of all conductors. If in electric cables they try to eliminate heat generation, then for a heating cable, the amount of heat released is the most important criterion. It performs the main function in the anti-icing system, namely, it heats the roof roof and the drain, thereby preventing the formation of icing.

The heating cable prevents:
the appearance of icing on the drains and the edges of the roof;
clogging of pipes with ice plugs;
destruction or distortion of gutters under the influence of various kinds of icing;
breakage of pipes under the force of the formed icing.

Characteristics of the heating cable

The climate in which the heating cables operate is unfavorable. Temperature fluctuations, the influence of moisture carry out a large load on the cable. And for this reason, it becomes necessary to provide heating cables with a list of characteristics:
the stability of its properties during (negative) temperature drops;
the tightness of the shell and the tolerance of atmospheric moisture;
exposure to UV radiation;
strong technical strength, due to which it is possible to resist the loads created by icing;
high degree of electrical insulation.

Cables are supplied in coils or specially prepared heating sections, which are cut pieces of a certain size with a sleeve and a wire that provides power to connect to the network. The most convenient choice would be a section, since its installation is easier. For roofs that have a complex layout and weirs, coiled cable is often used, because standard sections will not work in this case.

Types of heating cables

There are two types of heating cable base, due to which anti-icing systems function: self-regulating and resistive. Consider their features.

Type No1. Resistive cable

This type of cable is traditional. Its main feature is that the same output power is carried out over its entire length, as a result of which heat generation also evenly covers the entire length of such a wire. Usually, to heat the drainage systems, they use resistive cables with a heat output of 15-30 W / m and a temperature of up to 250C.
The eternal resistance of the heating resistive cable causes it to heat up consistently throughout its entire length. The power of heating is affected only by the strength of the current, without taking into account various external conditions, although they can affect the wire in different sections of its length.

Different sections of such wires can be located both under the sky and in snowdrifts, in leaves and in the pipe itself. In view of this, a different amount of heat will be required in any of the areas to prevent the formation of frost. As mentioned above, the entire length of the resistive cable is at the same heating level, and it will not be able to adapt to certain conditions.

Thus, in some parts of the wire that are in sufficiently warm conditions, there will be excess heat, which will lead to waste of thermal energy in vain. The operation of resistive cables constantly requires significant power consumption, which is partly wasted.

There are two types of resistive cables that differ in design: zonal and serial.

serial cable
The structure of a serial cable is elementary. Throughout its length, inside, there is a continuous conductive core, which is insulated. Residential is called copper wire.
To prevent the occurrence of electromagnetic radiation, this wire is grounded by placing a shielding braid on top of it.
The outer layer of a resistive cable is a polymer sheath, which prevents short circuits and also protects it from adverse external factors.
The total resistance of such a cable is equal to the total resistance of all its parts, which determines its main exclusivity. In this regard, if the length of the wire changes, the thermal power will change accordingly.
Monitoring of this type of wire must be carried out continuously, since the heat transfer process is unregulated. This includes the mandatory cleaning of accumulated debris, since it can cause overheating and burnout of the cable. It won't be possible to restore it.

Serial cables are divided into single-core and two-core. The first cable contains one core, the second, respectively, two. In the latter, the veins run in parallel and conduct current in directions that are different in direction to themselves, for this reason there is a leveling of electromagnetic radiation. For this reason, cables with two cores are safer than single-core ones.

Pros of Serial Resistive Cables:
acceptable cost;
flexibility, which gives options for placing the cable on various planes;
easy installation, during the implementation of which there will be no need to use unnecessary parts.

Cons of serial resistive cables:
constant heat transfer despite climatic conditions;
damage to the cable due to overheating at any point or intersection.

Zone cables

Zone cable - there is a modified version of the usual resistive cable. It contains two insulated wires, the function of which is to conduct current. They are located in parallel. The wire wrapped around them, which is wound in a spiral, has a high resistance.

This spiral, usually consisting of nichrome, closes with the first and second wires in turn. This happens due to the contact windows in the insulation. Then there are zones through which heat release passes. These zones do not affect each other. You can see that if overheating occurs, this wire burns out at some point, only one zone will break, but the others will remain working.
Since the zonal heating cable for drains and roofs is a chain of heat-producing parts that are independent of each other, it is possible to separate it into separate parts right where the laying will take place. It is important that the length of each part of the cable is a multiple of the heat-generating zone (0.7-2 m).

Advantages of zone cable:
low price;
lack of influence on each other of heat dissipation sections, due to which you can not worry about overheating of the cable;
easy installation.

Cons of zone cable:
constant heat dissipation regardless of climatic conditions;
the dependence of particles separated for installation on the total length of the zone where heating is applied.

Type No2.

In stock this cable has a huge functionality, in the heating system of drainage systems and roofs.
Its structure is much deeper than resistive. It contains two cores through which current flows (similar to a two-core resistive cable), they are connected by a semiconductor layer called a matrix. Then the following arrangement of layers follows: internal photopolymer insulation, shielding sheath (foil or wire braid), plastic external insulation. Double insulation increases the dielectric strength of the cable, well, and contributes to the transfer of shock loads.

The matrix is ​​dominant in a cable capable of self-regulation. Here it is able to constantly change as the climate requires. Its resistance will change. When there is an increase in temperature, the resistance of the matrix increases, and the heating of the cable decreases. This principle reflects the essence of self-regulation.
Regulation of power consumption and heating level is automatically decided by the cable itself. In addition, all sections of the cable independently determine the heating power of themselves, since they are independent of each other.
The cost of a self-regulating cable is about 2-3 times more expensive than a resistive one, and perhaps this is its main drawback.

The list of benefits is very wide, but stand out:
a system that adapts to the environment, changing the degree of heating depending on this;
economical consumption of electricity;
low power consumption (approximately 15-20 W/m);
durability, due to the fact that there is no overheating and burnout;
easy installation on all types of roofing;
the ability to divide it into separate parts (from 20 cm long) right where the laying will take place

The disadvantage of this wire is also:
long heating time
increased starting current in cases of temperature drop.

The composition of the anti-icing system
As mentioned above, the main (heating) part of the anti-icing system for drainage and roofing is the cable. In addition to it, the system includes other parts. The final version of the system will consist of:
heating cable;
thermostat;
RCD;
power unit;
fasteners;
supply wire that supplies voltage (it does not heat up);
couplings.

The operation of the thermostat directly affects the productive functioning of the anti-icing system. Due to this device switching of heating sections is possible. Thus, it becomes possible to limit their operation under certain climatic conditions by pre-setting their range. The value is determined by the thermostat using sensors installed where more water accumulates.

All standard thermostats have a temperature sensor. In small systems, a dual-range thermostat is often used, in which there is a choice of cable temperature settings for switching.
There is such a thermostat as a weather station. It is much more effective in controlling the functioning of the system. It has built-in sensors that are designed to capture many parameters that affect the occurrence of icing, in addition to recording the temperature. These include the presence of moisture residues on pipes and roofs, air humidity, etc. When using a weather station, up to 80% of electricity is saved, because its operation is carried out in the same way as the program mode was programmed.

Heating cable installation

To lay the anti-icing system, heating cables are attached:
in vertically installed drainage pipes;
along the edge of the roof;
in horizontal gutters;
in valleys;
along the line of intersections of the roof and adjacent walls.

Each of the cable laying options is individual.

On the edge of the roof
In this area, the cable is laid according to the principle that it is about 30 cm higher than the edge of the outer wall. And this is how they call the “snake”. The height of the snake itself should be 60, 90 or 120 cm.
When the installation takes place on a metal tile, it is necessary to install a coil of wire at all points from the bottom of the surface. If the installation takes place on a metal seam roof, then it is necessary to raise the cable along the first seam to the required height, after which, lower it to the drainage gutter through the reverse side of the seam. The cable cycles through the gutter to the seam.

In the case when there is no seam, on a pitched roof, icing may occur. To prevent this, the "dripping loop" or "dripping edge" scheme is used.
In the case of the first scheme, water flows off the cable. In view of the events described above, its installation is carried out by a snake. The cable must be placed 5-8 cm lower than the roof.
The second scheme occurs in a similar way, except that the cable is attached at the edge of the roof (drip).

In valleys and where roofs and walls intersect
Ice formation easily occurs in valleys and other places where roof slopes meet. In such a situation, it is necessary to lay the cable in 2 threads, along the junction line for 2/3 of the distance. And this is how a non-freezing passage appears, due to which the melt water drains.
Where the roof and walls are connected, a similar method is used. The cable is installed in 2 threads at 2/3 of the slope height. The gap between the wall and the cable is about 5-8 cm, and from thread to thread about 10-15 cm.

in the gutters
In a trough located horizontally, the cable is laid in full length with one or more lines running in parallel. The number of threads will depend on how wide the gutter is. In the event that the tray is less than 10 cm, then it is possible to place 1 thread, in 20 cm, 2 threads. The number of threads increases by 1 for every 10 cm of width. It is necessary to lay the cable leaving a distance of 10-15 cm.
To strengthen it in the gutter, they resort to mounting tape or plastic clips. In addition, it is possible to independently manufacture fasteners in the required quantity from steel tape. Its shape is easy to adjust to the shape of the clamp.
Due to self-tapping screws, parts of the mounting tape and clamps on the walls of the gutters are strengthened. Next, silicone sealants seal the cuts made. The required distance from element to element is 30-50 cm.

In the drainage pipe X
The formation of icing in the drain funnels prevents the flow of melt water flowing down from the roof through it. It is for this reason that this place is mandatory for installing the cable. One strand of cable is placed in a pipe with a radius of up to 5 cm. If the pipe is larger, 2 strands are placed. The cable is attached at the beginning of the pipe to the walls due to steel brackets.
Other cable strands (several turns of the spiral) are attached at the top of the pipe and at the bottom, for stronger heating.
In cases where the pipe length exceeds 3 meters, the cable is lowered and fixed by a chain or cable with fasteners, which are hung on a metal rod installed on the gutter.

Helpful video. Heating cable installation on the roof

Everyone knows that the operation of the roof in the winter is much more problematic than in the summer. This is due to the fact that due to negative temperatures and a large amount of precipitation, ice, icicles and a snow cap form on some sections of the roof.

To prevent spontaneous slippage of ice and snow from the slopes, special snow retention structures are often not enough, so you have to resort to periodic mechanical cleaning.

Due to the low ambient temperature, as well as the alternation of frosts and thaws during the winter, it is often not possible to get rid of snow on roofs in a timely manner. This, in turn, causes the danger of falling snow masses and blocks of ice on people passing in the immediate vicinity of the house.

To minimize traumatic roofing mechanical cleaning and make the operation of the house safe, electric heating of the roof is used, the device of which we will discuss in this article.

As a rule, the roof of a private house is a pitched structure, consisting of two or more slopes located at an angle of 30-50 degrees to the base. The roof structure is specially designed in such a way that melt or rain water is drained as efficiently as possible, and snow melts better.

Experienced craftsmen note that the following types of roofing are more actively covered with ice and icicles:

1. Warm type roofs. Experts note that a warm roof, in which the slopes are thermally insulated and the attic floor is heated, is more prone to icing in the winter. This is explained by the fact that due to the high temperature of the lower surface of the roofing material, the snow cap on the slope begins to melt, and during frosts it becomes an ice crust.
2. Roofs with metal coatings. Roofing materials based on metal, for example, metal tiles or corrugated board, have a higher coefficient of thermal conductivity, therefore, due to temperature changes, they are more likely to be covered with ice than roofs covered with tiles, slate or shingles. For the same reason, ice formation occurs inside metal gutters.
3. Low slope roofs. From slopes with a slope of more than 45 degrees, snow masses easily slide off on their own, and on gentle slopes, snow accumulates, and an ice crust forms in places where it comes into contact with the roofing material.

Important! If the roof has at least one icing risk factor, a roof heating system is required. The use of this simple and inexpensive device will greatly simplify and secure the operation of the roof structure, as well as increase its service life.

Causes of the problem

With the right choice of the roof slope, the observance of the technology of its construction and the use of high-quality materials, neither on its surface, nor in the gutters and downpipes, frost should form, regardless of weather conditions.

Most often, the problem of ice formation occurs due to flaws during installation. Typically, roofers identify the following reasons for the formation of ice on the roof:

• Poor thermal insulation. The most common cause of roof icing is insufficient or poor-quality thermal insulation of slopes. If the attic floor is heated, and the slopes are not insulated, the roof surface heats up, the snow melts on it even at low temperatures, and icicles form on the roof overhangs.
• Daily temperature fluctuations. Even in winter, the sun shines, therefore, due to the heating of the sun's rays, the snow on the roof surface melts. In the evening, at lower temperatures, the water turns into ice.

Please note! If the problem of roof icing arises due to poor-quality thermal insulation of the slope, the most obvious way out is to additionally insulate it with thermal insulation material with a thickness of at least 150 mm. In other cases, in order to forever forget about putting on and icicles, electric heating of the roof is performed.

Icing Hazards

The problem with icing is solved by organizing the heating of the roof with the help of electric thermal cables. If icicles and frost are not dealt with, the following dangers arise:

1. Increasing the load on the truss frame. Raw snow, and especially ice, weighs quite a lot, so in winter the load on the truss frame of the structure increases. The valley, roof light and places of contact with vertical surfaces, where the bulk of the snow accumulates, suffer from this the most. It is necessary to get rid of snow so that the roof does not collapse.
2. Damage to roofing material. When the ice crust formed on the surface of the slope due to temperature changes begins to slide down, it scratches and damages the roofing. Each scratch from exposure to water becomes a hotbed of corrosion.
3. There is a danger of a spontaneous fall of snow mass from the slope. If the roof is not cleaned in time, snow and ice can fall from it at any time. This poses a threat to people passing by and parked cars.

Important! Heated roof with self-regulating wires is not covered with ice. Thermal cables, if necessary, heat the surface of the roofing material, gradually melting the snow cap, and then evacuating the melt water into a special drainage system.

Heating system and its functions

Roof heating is a system for maintaining the temperature on the surface of the roofing material, consisting of heating elements, water and precipitation sensors and control relays, which must be fixed along gutters, valleys and all areas where snow accumulates.

Cable heating of the roof maintains the desired temperature, ensuring uniform and gradual melting of snow, as well as directing it to the drainage system. The functions of electric roof heating are as follows:

• Prevents the formation of icicles along the roof eaves.
• It does not allow clogging of the drainage system, due to which the melt water is sent without loss through the gutters to the storm sewer.
• Reduces the load on the truss frame of the structure, preventing deformation or collapse of the slope.
• It completely replaces the mechanical cleaning of the roof surface, that is, the heating wires completely melt the snow cap.
• Extends the service life of the roofing by minimizing the mechanical impact on its surface.
• Automates operation. Thanks to sensors that record temperature, humidity and precipitation, the system automatically starts up without human intervention.

Note! If a metal roof is operated in areas with a cold climate, roof heating is necessary. Installation of the system solves the problem of icing of slopes, and prevents the growth of icicles. To determine the required number of heaters, the calculation of the heating power is used. The power of the system must correspond to the average annual temperatures in winter, the amount of precipitation and the area of ​​roof slopes.

Device

Maintaining a constant temperature on the surface of the roofing can be carried out using a cable that is powered by the electrical network and transfers heat to the environment. The heating system consists of three parts:

1. heating. The heating part of the system includes an electric cable for heating, which is laid along gutters, funnels, valleys. One or two wavy lines of a thermal cable can completely melt the snow. During laying installation of heating wires from can be cut into pieces of the desired length, bent, give any shape. The resistive cable has the advantage of being more compact and easier to install.
2. distribution. The distributing part of the device consists of mounting elements, various sensors that record the state of the environment, as well as junction boxes. The task of such a system is to distribute its power, transfer power to the heating wire, ensure the transmission of signals from sensors to the control unit and vice versa.
3. manager. The device is controlled by thermostats, starting and safety systems, as well as a control panel. The self-regulating heating system is considered the most perfect, but installations of this design require special self-regulating cables.

Remember! The heated part of the roof must be roof overhangs, valleys, drain funnels, gutters. The length of the wire should be enough to lay it in wide loops in 1 or 2 rows.

Video instruction

The main component in the heating system is the heating element, which forms a large part of its cost.

The cheapest heating element is a resistive cable, the only advantage of which is the price. The principle of operation is similar to an electric heater: a current flows through the conductor, generating heat.

However, there are a number of significant disadvantages:

• When resistive cables cross each other, they burn out
• When in gutters with leaves and dirt, they burn out
• The length of the resistive cable must not be changed during installation as it is only used in fixed lengths
• Resistive cable needs three times more than self-regulating
• Low energy efficiency

For the entire time of our engineering center, we have not installed a single meter of resistive heating cable, since the most important thing for our company is the reliability, quality and durability of heating elements and other components of the roof heating system, and this can only be achieved using a self-regulating heating cable. Raychem cable.

The principle of self-regulation is to change the power of the cable depending on the ambient temperature, thus ensuring high energy efficiency of the roof heating system. When melt water hits the heating cable, it starts to produce its maximum power, and after the water is removed, it goes into a standby state, reducing the power by half. Only high-quality heating elements can provide such a wide range of power changes, and Raychem cables provide it thanks to the radiation-crosslinked heating matrix used in them. When using this matrix, it is possible to reduce the aging effect (power loss) of the heating cable to 10-15% in 10 years, unlike cheap self-regulating cables, in which there is no power variation range and the aging effect reaches 30% per year.