Accumulation of snow on the roof of a house, icing of gutters and the formation of icicles - these weather factors not only damage the roof, but also create a danger for people below. Of course, you can dump the snow cover immediately after it falls and knock it down ice blocks with a long pole, but who can guarantee that the roof and gutters will not be damaged in this way, and that a falling icicle will not cause harm to health or property. But there are very effective method eliminate all these phenomena in one fell swoop. An anti-icing system, which you can install yourself, will melt the snow in time and prevent ice from forming in the most critical areas.
The roof and gutters are safe and can perform their functions normally until the air temperature reaches negative values. After this, the process of water crystallization begins, which is accompanied by negative phenomena:
In order for the sediment drainage system to work successfully even in the most severe frost, electric heaters are installed in the most critical places. They prevent the accumulation of snow and the appearance of an ice crust, helping to reduce the mechanical load on the roof and preventing blockages in the path of melt water.
The main function of a de-icing system is to prevent snow and ice from accumulating on potentially hazardous areas of the roof.
Most often, the following elements of drains are equipped with heating cables:
In addition, wastewater collection areas near storm drains, as well as trays and other elements of the drainage system, are equipped with electric heating.
Neither mechanical nor chemical methods removing ice and snow. The first requires the use of human resources and special equipment, and cleaning with shovels and ice axes is unsafe for the roof and gutters. The second requires the application of special expensive emulsions to the roof, which must be periodically updated.
The principle of heating roofs and gutters is in many ways similar to the functioning of heated floors. The main element electrical system anti-icing is a heating circuit that includes one or more sections of the heating cable, as well as fastening and insulating elements for its installation. The functionality of electric heaters is ensured by power and signal cables, as well as a variety of switching and switching devices. To control heating, a thermostat, temperature and humidity sensors, a time relay and protection (safety) equipment are used. The anti-icing system can be turned on in simple or smart mode, which provides synchronization with a weather station.
The operation of the heating system for roofs and gutters in automatic mode is possible thanks to a control unit (thermostat or weather station) and sensors that monitor the condition environment
The operation of the heating circuit is simple and reliable. The heaters are turned on based on signals from temperature and humidity sensors, which are installed in shaded areas and the highest points of drains. When the air temperature drops below the set value, the temperature sensor will give a command to turn on the heaters. However, voltage will be supplied to the cable only if the humidity sensor is in a certain state. Heating will turn on only at low humidity values, indicating freezing of the liquid. The power supply will stop when the alarm sensor is in the water. Such an algorithm prevents the system from running idle and contributes to its efficiency.
The functionality of anti-ice systems is ensured by a heating cable, which is laid along the edge of the roof, in gutters and other places where snow and ice may accumulate.
The design of flexible cable elements makes it possible to heat roofs of the most complex configuration. The design of the anti-icing system depends on the climatic characteristics of the region, the type of cable and the degree of thermal insulation of the roof.
To set up a reliable anti-icing system, two types of heating cables are used:
Heating of this type of cable occurs due to ohmic losses in the core, which has high resistance.
Depending on the design, a resistive cable may have one or two heating cores
The heat dissipation of modern resistive heaters is up to 30 W/m, and the temperature can reach 250 °C. The section clearly shows internal structure cable - metal conductor, insulation layer, copper braid and protective sheath. In addition, there is a type of two-core cables with an additional conductive element. Thanks to it, the connection can be made from one end. This greatly simplifies installation and reduces the cost of work by reducing the length of power circuits.
The advantages of heaters of this type include:
The disadvantages of cables operating on the principle of resistive heating are:
Since the power of the resistive element does not depend on external conditions, when using a cable of this type, correct calculation is necessary, otherwise it will be difficult to avoid unnecessary energy costs.
A resistive cable can be connected from one or both ends - it all depends on the number of heating cores
A self-regulating cable consists of current-carrying conductors placed in a medium made of special plastic. The presence of graphite grains in its composition turns the system into a long chain with many parallel variable resistances. The conductivity of the internal filler changes depending on the temperature, which ensures regulation of the heater power - as the temperature drops, the cable will generate more heat.
Self-regulating cable is a high-tech electric heater
Advantages of self-regulating cables:
The disadvantages of self-regulating elements include more high price, which, however, is compensated during their operation.
The most effective anti-icing systems are obtained using both types of heaters. Resistive cable, as having a higher power density, is recommended to be installed on flat areas of the roof, and self-regulating cable - in gutters, funnels and drainpipes.
Designing a snow melting system includes selecting heating locations, calculating the required cable power, as well as drawing up drawings, diagrams or sketches. The documentation must contain information about the type and number of heaters for each zone, sensor installation locations and electrical connections.
At the first stage, roof drawings are studied, with the help of which the number and type of heated zones are determined. Experts recommend including the following places in the snow melting system:
The joints of adjacent roof slopes are equipped with a heating cable laid at 2/3 of their height
Next to the funnels, the heating cable is laid on an area of 1 square meter. m
To heat trays and drainpipes, the heating cable is laid in two parallel lines
Various ways of laying out cable heaters can make protection from snow and ice more effective
In addition, the heating cable is laid around the perimeter of the skylights, in a meter-long zone around the water collectors, as well as along the water outflow path. To ensure functionality storm sewer, it is necessary to consider heating the main line up to the sewer.
Not only the roof and gutters are equipped with heating, but also drainage areas, as well as elements of the drainage system
Roof slopes with a slope of more than 45 degrees do not require the installation of heaters, since snow melts off their surface naturally. However, to ensure functionality drainage system all its elements should be equipped with a heating cable in accordance with the rules stated above.
The power of the heating cable is calculated based on the area of the individual zones that require installation of a snow melting system. To calculate this value, we are guided by data obtained in practice:
On flat surfaces, install the cable in a zigzag pattern, not exceeding the bend radius recommended by the manufacturer. Using the laying diagram, the length of the cable is determined and, based on the data obtained, the total power of the snow melting system is calculated.
Before installation you need detailed drawing indicating the heating locations and the method of laying the heating cable
To monitor and control the heating system for roofs and gutters, unified modules are used, the design of which provides for the connection of a power wire, heaters, as well as temperature and humidity sensors. The control unit is mounted in a place convenient for monitoring and control. Signal sensors are installed taking into account the need for their inspection and maintenance.
The anti-ice system is monitored and controlled using a variety of sensors connected to an electronic thermostat or weather station
After completing all necessary calculations begin preparatory activities, collect necessary tool and purchase materials and equipment. After this, the installation of the anti-ice system begins.
Foundation preparation includes removing inoperative elements of the old snow melting system, if one was previously installed. Places where the heating cable is laid are cleared of accumulated debris and dirt. In addition, the roof is inspected to identify objects and sharp edges that pose a risk of cable damage.
Assembling the heating system begins with attaching the electronic module. It is best to use a separate control cabinet for its installation. Installation of other structural elements is carried out in the following sequence:
Alarm sensors are installed in such a way as to ensure their clear and timely response
To secure the heating cable, you can use a special perforated tape
For installation and fastening of the heating cable in drains longer than 3 m, a metal cable is used
A number of operations, such as winding an additional layer of insulation in places where the clamps are installed, sealing the ends electric heaters, signal and power cables, etc., can be performed on the ground or indoors. This will reduce the risk of damage to the roof during installation activities.
Heating cables are connected in strict accordance with the switching and protection diagram
According to SNiP 3.05.06–85, which regulates the installation and operation of electrical devices, installation of heating cables can be carried out at an outdoor temperature of at least minus 15 °C. The installation of heaters must be completed before the first snow falls and ice forms on the roof. The best time The last weeks of autumn can be considered for installation. If, for any reason, the work was delayed until snow caps and ice plugs appeared on the roof and in the gutters, then careful cleaning of the cable installation sites from precipitation will be required.
Installing an anti-icing system is associated with risk, so working without insurance is prohibited
The heating cables are turned on and off within the specified temperature limits and in accordance with the state of the humidity and precipitation sensors at the command of the monitoring and control module. Depending on the complexity and functionality, these devices are divided into two types:
Of course, the first option, due to its design simplicity, costs several times less than the second. Despite this, use it in regions with high humidity is not recommended, since in this case there is a risk of incorrect interpretation of the temperature sensor data. As a result, instead of timely melting of snow, ice deposits may accumulate on the roof.
Weather station of the anti-ice installation and its connection diagram
The weather station does not have these disadvantages, but has more complex design, and therefore less reliable. Nevertheless, choosing this option will allow you to build a snow melting system that can operate automatically and save energy due to more sensitive control.
To protect system elements in case of excess load current or short circuit in electrical diagram install circuit breaker. In addition, they use a residual current device that monitors current leakage through the insulation and, if it occurs, can de-energize the entire system or turn off individual sectors of the heaters.
Reliable, durable operation of the anti-icing system is guaranteed not only by correctly performed installation, but also by regular, timely maintenance. Here are a few operating rules that contribute to trouble-free operation of the equipment:
In conclusion, I would like to give advice: do not allow random people to install and maintain the circuit. Only qualified workers who have undergone specialized training know how to handle such a delicate and sensitive system.
With the appropriate knowledge and minimal skills, installing an anti-icing system is not difficult. At the same time, working at height requires utmost attention and composure. In addition, we recommend brushing up on safety precautions when working with high voltage and strictly follow them during installation and operation of the equipment.
During winter thaws and off-season periods, the operation of drainage systems is at risk. Ice forms in gutters and pipes, which can quickly grow and form entire ice plugs. They slow down the drainage system and sometimes block it completely.
In addition, frozen ice increases the weight of gutters, leading to their collapse and rupture. Such consequences can be avoided with the help of anti-icing systems, the main element of which is a heating cable for gutters and roofs.
Let's start with the main concepts. What is a heating cable? It is a current conductor capable of converting electrical energy into thermal energy. The amount of heat generated depends on the strength of the current and the resistance of the conductive material. If you remember the course school physics, then it turns out that any conductor has this ability. But! For an electrical cable, a similar thermal effect is n desirable, therefore, due to the design, they try to reduce it. And for the heating cable it’s the other way around. The more heat it can convert from electricity, the better.
In an anti-icing system, the heating cable performs the most important function heating the drainage and roofing elements, making the formation of ice, icicles and snow canopies impossible.
Electric heating prevents:
Electric cables for heating drains and roofs operate in difficult conditions - under the influence of moisture, negative temperatures, mechanical loads. Therefore, it is necessary that the cables have the following set of characteristics:
Cables are supplied in coils or ready-made heating sections - cut pieces of a fixed length with a coupling and supply wire for connection to the network.
Sections – more convenient option, which is easier to install. Cable in coils is usually used for drainage systems and roofs of complex configurations, for which standard sections are not suitable.
Anti-icing systems can operate on the basis of two types of heating cables: resistive and self-regulating. Let's look at the features of each of them.
The most common, traditional option, characterized by the same output power along the entire length and the same heat dissipation. Used for heating gutters resistive cables with heat release 15-30 W/m and operating temperature up to 250°C.
A resistive cable for heating gutters has a constant resistance and heats up equally over its entire surface. The degree of heating depends only on the current strength, without regard to external conditions. And these conditions for different parts cables may vary.
For example, one section of the wire may be in the open air, another in a pipe, and a third hidden under foliage or snow. To prevent ice from forming, each of these areas requires a different amount of heat. But a resistive cable cannot self-adjust and change the degree of its heating. Any part of it will have the same power and degree of heating.
Therefore, part of the thermal energy of the cable will be wasted on heating those parts of the pipe and roof that are already in “warm” conditions. Due to this, the electricity consumption of a resistive cable is always relatively high, but partially unproductive.
Depending on the design, resistive cables are divided into 2 types: serial and zone.
The structure of a serial cable is very simple. Inside it, along its entire length, there is a continuous conductor core, covered with insulation on top. The core is a copper wire.
So that it does not become the cause of negative electromagnetic radiation, a shielding braid is placed over the wire. Additionally, it acts as a grounding connection. The outer layer of a resistive cable is a polymer sheath that serves to prevent short circuits and protect against external conditions.
A feature of a serial cable is that its total resistance is equal to the sum of the resistances of all its pieces. Therefore, when the length of the wire changes, its thermal power also changes.
Since the heat transfer process cannot be adjusted, constant monitoring of the cable is required, including removing accumulated debris. Leaves, branches and other debris can cause the cable to overheat and burn out. It cannot be restored.
Serial cables can be single-core or double-core. A solid conductor has one core. In a two-core - two wires running in parallel and conducting currents in opposite directions. As a result, electromagnetic radiation is leveled, making two-core cables safer.
Serial resistive cables have the following strengths:
Disadvantages include stable heat release, independent of weather conditions, and failure of the entire cable due to self-crossing or overheating at one point.
In addition to the usual resistive cable, there is an improved version of it - a zonal (parallel) cable. Its design has two parallel insulated conductors. Around them is a high-resistance heating wire wound in a spiral.
This spiral (usually nichrome) through the contact windows in the insulation is closed alternately to the first and then to the second core. Heat release zones independent from each other are formed. If the cable overheats and burns out at one point, only one zone fails, the rest continue to work.
Since the zonal heating cable for roofing and gutters is a chain of independent heat-generating sections, it is possible to cut it into fragments directly at the installation site. In this case, the length of the cut pieces must be a multiple of the size of the heat-generating zone (0.7-2 m).
Advantages of using a zone cable:
Disadvantages include stable heat dissipation (as with a serial cable) and the fact that the size of the pieces cut for installation depends on the length of the heating zone.
This type of cable has great potential in heating systems for gutters and roofs.
Its structure is more complex than that of its resistive analogue. Inside the element there are two conductive cores (like a two-core resistive cable), connected by a semiconductor layer - a matrix. Next, the layers are arranged as follows: internal photopolymer insulation, shielding shell (foil or wire braid), plastic outer insulation. Two layers of insulation (inside and outside) make the cable resistant to shock loads and increase its dielectric strength.
The main distinguishing detail of a self-regulating cable is a matrix that changes its resistance depending on the ambient temperature. The higher the ambient temperature, the greater the resistance of the matrix and the less heating of the cable itself. And vice versa. This is where the effect of self-regulation manifests itself.
The cable automatically and independently regulates power consumption and heating level. In this case, each section of the cable operates autonomously and, independently of other sections, selects the degree of heating for itself.
A cable with a self-regulating effect costs 2-4 times more than a resistive cable. But it also has many advantages, the most notable of which are:
In addition to the high price, the disadvantages of this option include long heating times, as well as a high starting current at low ambient temperatures.
As already noted, the cable is the main (heating) element of the anti-icing system for gutters and roofs. But not the only one. To assemble a fully functioning system, the following components are used:
The productivity of the heating system largely depends on the thermostat. This device allows you to turn heating sections (cable) on and off, limiting their operation in a pre-fixed range of weather conditions. The thermostat can determine their value using special sensors that are installed in places largest accumulation water.
A conventional thermostat is characterized by the presence of a temperature sensor. As a rule, for small systems, a dual-range thermostat is used with the ability to adjust the cable on and off temperature.
A specialized thermostat, called a weather station, controls the operation of the system more effectively. It contains several sensors that record not only temperature, but also a number of other parameters that affect the formation of ice. For example, air humidity, the presence of residual moisture on pipes and roofing. Weather stations operate in the mode of established programs and allow you to save up to 80% of electricity.
To install an anti-icing system, heating cables are laid:
Features of cable laying in these areas have their own differences and features.
In this area, the cable is laid like a snake so that it is above the edge outer wall by 30 cm. The height of the snake in this situation is 0.6, 0.9 or 1.2 m.
When installing a cable on a metal tile, a turn of wire is laid at each lower point of the wave. Installation on a metal seam roof requires a different approach. The cable rises along the first seam to the desired height, then goes down to the gutter on the other side of the same seam. It passes along the gutter, reaches the next seam and repeats the cycle again.
If on pitched roof If there are no gutters, then significant ice growths and icicles can form on its edge. To prevent this from happening, the cable is laid according to one of two possible patterns: a “dripping” loop or a “dripping” edge.
The "drip" loop design assumes that melting water will flow and drip directly from the cable. To do this, the cable is mounted with a snake so that it hangs 5-8 cm from the edge of the roof.
The “dripping” edge scheme is organized according to a similar principle. Only the cable is fixed to the edge of the roof (dripline), laying it traditionally with a snake.
Ice easily forms in valleys and other places at the junction of roof slopes. The cable here is laid in 2 threads, along the joint, 2/3 of its length. Due to this, a frost-free passage is formed through which melt water can flow.
A similar method of constructing a frost-free passage is used at the intersection of the roof and wall. Here the cable is also laid in 2 threads at 2/3 of the height of the slope. The distance from the cable to the wall is 5-8 cm, and the distance between its threads is 10-15 cm.
In a horizontal trench, the cable is laid along its entire length in one or more parallel threads. The number of threads depends on the width of the gutter. If in a tray up to 10 cm wide it is enough to put one thread of cable, then in a tray with a width of 10-20 cm there are already two threads. For a wider gutter (more than 20 cm), their number is increased by adding one thread for every next 10 cm of width. Lay the cable so that there is a space of 10-15 cm between the threads.
To secure the cable in the gutters, use mounting tape or special plastic clips. It is also possible to manufacture fastenings in required quantities yourself - from a steel strip, which can easily be shaped into a clamp. Clamps and elements of the mounting tape are secured to the walls of the gutters with self-tapping screws. The resulting holes are sealed silicone sealant. A distance of 0.3-0.5 m is maintained between fastening elements.
Ice often forms in drain funnels, blocking the path for melt water to drain from the roof. Therefore, cable laying is mandatory here. One thread of cable is placed in a pipe with a diameter of up to 10 cm, and two threads with a diameter of 10-30 cm. At the entrance to the pipe, the cable is secured to the walls using steel brackets.
In the upper and lower parts of the pipe, enhanced heating is required, which is carried out by laying additional cable strands - in the form of a “dripping” loop or several spiral turns.
If the length of the pipe exceeds 3 meters, a chain or cable with fasteners is used to lower the cable and secure it. The chain (cable) is suspended on a hook screwed into the wooden elements of the roof or a metal rod fixed to the gutter.
The basic principles of installing a heating cable as part of an anti-icing system are discussed in the video:
It turns out that there is nothing complicated in installing a heating cable. Having understood the simple characteristics of cables and the nuances of their installation, you can build a reliable anti-icing system in a short time.
Consuming very little electricity, this design will help you forget about icicles and ice on the gutters and roof of your house for a long time.
IN winter period And in early spring You can often see huge, menacing-looking icicles hanging on the roof eaves of houses, ice-covered or, even worse, gutters disabled by the mass of ice. Properly organized heating of gutters can prevent such phenomena - protect residents of the house from falling ice from the roof, and protect the drainage pipe system from the need for annual repairs.
In our article, we will analyze the factors influencing the appearance of ice on roof overhangs and gutters, and also describe in detail how to choose a suitable heating cable, its installation scheme, and organize heating of the roof and gutters on your own.
Icicles on the roof overhang and ice in the gutter occur due to two main reasons:
Pro tip: It is possible to prevent heating of the roof in winter by organizing a so-called cold roof (with an unheated ventilated attic), as well as by properly arranging the roofing pie - with a properly arranged ventilation gap and sufficient thickness of insulation.
To prevent the formation of ice, various systems for heating gutters and roofs are currently used, but almost all of them are based on the use of a special heating cable and automation equipment.
Let's take a closer look at what types of heating cables and control equipment exist, and which ones would be preferable for selection.
There are two main types of heating cables for roofs and gutters:
Each type of heating cable is capable of providing the same efficient heating roofs and gutters. However, each of them has its own unique advantages. So, the main advantage of a resistive cable is that it is much more low price compared to self-regulating. At the same time, the second type is more efficient in terms of energy consumption and is unpretentious to installation conditions.
As the outdoor temperature rises, the number of current-carrying paths in the cable matrix decreases, due to which the power and amount of electricity consumed decreases. The temperature of the self-regulating cable also decreases. All this avoids the need to use a temperature sensor that automatically regulates the cable.
Pro tip: It is considered to be the most effective in terms of cost and quality ratio combined system heating cables. Typically, inexpensive resistive cables are used in the roofing portion of the system, while heating of gutters and gutters is provided by self-regulating cables.
As for calculating energy consumption and choosing the power of heating cables, the norm for resistive-type products is a cable with a power in the range of 18-22 W per linear meter, for self-regulating - 15-30 W per meter. However, it should be taken into account that if there is a drainage system made of polymer materials, the cable power should not exceed 17 W per linear meter, otherwise there is a risk of damage to the drainage due to excessively high heating temperatures.
In addition to the heating cables themselves, heating systems also consist of the following main components:
When using a conventional thermostat in a cable system, the user will need to independently turn the system on in the presence of precipitation and turn it off in the absence of it. The weather station allows you to fully automate the process of system operation and even program time delays for its shutdown. However, in terms of cost, conventional thermostats are significantly more profitable.
The heating cable should be laid in places where melt water drains and in areas where ice forms:
Installation of heating gutters and roof eaves is carried out according to the following rules:
So, we have looked in detail at how you can organize cable heating drainage system with your own hands, understood the structure of the system and the rules for choosing its components. We hope that our tips and recommendations will be useful to you and you will be able to put them into practice.
During the transitional time of year from the cold to the warm season, home owners face the urgent question of how to prevent roof icing. Until now, manual harvesting has been considered the prevailing method. But this method is already outdated. Such work is labor-intensive and dangerous, and the results are short-lived. There is a more modern, safe and effective way - heating the roof.
Snow and ice on the roof, icicles on the eaves, ice in the drain pipes - all this causes many problems. Significantly increases the load on rafter system, passers-by suffer, architectural elements of the roof are damaged. The corrugated sheet becomes covered with rust; the material from which the gaskets under the fasteners are made is destroyed. When the ice starts to melt naturally, the roof is leaking.
There are several reasons for icing:
The large difference between the temperature of its surface and the ambient temperature is the main reason for the formation of ice. The snow begins to melt and freezes, causing ice masses to form.
The solution to the problem is to regulate the temperature of the roof surface. It should be the same as the ambient temperature. None of the commonly used methods for controlling icicles and ice on a roof work this way.
Management companies continue to send housekeeping employees with shovels and insurance onto the roofs of high-rise buildings. Owners of private houses climb onto the roofs themselves. Both of them risk their health and use tools that damage the roof. Mechanical impact with a shovel wears out the surface of the roofing material. Leaks will form in damaged areas over time.
There is an alternative method: a chemical composition is applied to the ice crust and icicles with a brush, which “eats” the ice. And a completely atypical option for Russia is the use of hot steam. Running on a slippery roof with boiling water in a kettle is doubly unsafe and simply absurd, but professional equipment it is prohibitively expensive. The only effective way to prevent icing of houses is to heat the roof and gutters.
Heating benefits:
The advantages of the system offset the disadvantages, but, nevertheless, they exist:
Anti-icing systems come in two types: electric and water. Electric, in turn, are divided into cable and infrared.
The heating cable based system is by far the most common. Its configuration is quite simple:
The control unit is the “heart” of the system. It controls all sensors, thermostats and the emergency shutdown system. Sensors determine the level of precipitation and the temperature of the roof and air. If necessary, they automatically start the heating cable.
The distribution network provides communication between all elements of the system and provides power to the cables. This is a kind of conductor from the energy source to the heating elements. The heating (heating) cable is the outer part of the system, which is attached to the roof, eaves, and drain. Elements inside the cable convert electrical energy into heat, causing snow and ice to melt.
The heating cable is available in two versions: resistive and self-regulating. A resistive cable is simpler and costs less. It has a fixed linear power (that is, its ability to transfer heat per 1 square meter of surface area). To heat the roof, you need a cable with a power of 20 W/m when connected to 220-230V. The number that shows the total power over the entire area must be divided by 3, the maximum permissible deviation is 15%.
The cable warms up evenly on all areas of the roof; this feature cannot be adjusted.
Types of resistive cable:
The heating cores of the resistive cable are protected by an insulating layer; on top of it there is a copper braid covered with an outer sheath. This multi-layering protects the cable from overheating and freezing, moisture, and mechanical damage. For hard roofing materials (corrugated sheeting, slate, tiles), you can use a cable in any sheath. For materials containing bitumen (roofing felt, ondulin, onduvilla, soft tiles) – only cable with fluoropolymer sheath.
A self-regulating heating cable has an advantage over a resistive one. It is highly sensitive to temperature changes and can regulate the level of heat generated. In the shade it will heat up more than in the sun, in the heat - less than in the cold. This provides high-quality anti-icing and economical electric heating, because energy is not wasted. Inside the self-regulating cable there are copper conductors, a heat transfer regulating matrix, a protective sheath and braid, and on top there is a universal sheath.
The cable can be cut anywhere. Due to this feature, you do not have to overpay for excess footage.
Advantages of cable heating:
Disadvantages of a heating cable:
For the Russian market infrared thermal equipment remains new. It is still difficult to evaluate its merits, since it is used infrequently, especially as an anti-icing system for roofing. And this is a big omission, because IR systems are in many ways superior to cable and water heating. Their main difference is in the method of thermal exposure. Electrical energy is converted by elements into infrared radiation, which has properties similar to sunlight.
The system consists of a base, heating elements, electrical conductors and protective film. The base is made of high-strength polypropylene and a Mylar backing. The first layer is stabilizing and protective, so IR roof heaters are not afraid of moisture and cold, and the second layer acts as a shielding surface so that heat does not escape downwards. The heating elements are made of carbon fiber. It gives off 98% of the heat.
The conductive core is replaced by thin copper-silver plates. The elements are glued together resistant to high temperatures adhesive composition. The upper “shell” protects the system from exposure to the external environment, and the roof from overheating.
Advantages of IR systems:
Flaws:
According to the principle of operation, it resembles cable anti-icing systems: pipes through which hot water flows are mounted on (or under) the roof surface. It is presented in two types: a system that operates from an electric or gas boiler, and combined electric water heating.
In the first case, water is supplied to the pipes from a separate boiler, in which it is heated to desired temperature, and in the second, the pipes are already filled with liquid and a resistive cable is installed inside. There is no need for a boiler; the pipes are connected to the control system almost like a cable.
Advantages of water heating:
There are still more disadvantages to water heating:
Architecture modern houses can be very intricate. There are not only buildings with unusual facades and layouts, but also roofs of non-standard shape. Among the possible options are flat, single-pitched, gable, gable, multi-gable, hip, hipped, attic, dome, spherical, figured. There are even concave roofs.
The more complex the shape of the roof, the more snow masses are retained on it and the more ice and icicles are formed when the snow melts, and the more difficult it is to clean it manually.
Another classification also plays a role: cold, warm and hot roofs.
Attics under high roofs are usually used as living quarters. gable roofs and mansard roofs. The minimum slope is found only on flat roofs. The snow melts very actively on them, even if it is -10 or below. The water circuit for mansard roofs is inefficient. As an anti-icing system, it is better to use a self-regulating cable with a power above 20 kW/m. Alternative option– finishing of the roof from the inside with roll IR film. This will simultaneously help retain heat inside the living space in the attic.
Heating a flat roof is the most difficult. Besides the fact that the snow flat surface It doesn’t slide anywhere and is actively melting, there is nowhere for the resulting liquid to drain. At minimum slope it simply remains a puddle on the surface of the roof, so it is necessary to install drain funnels. Funnels also need heating. The drainage system can be of two types: traditional using drain holes and gravity-vacuum.
In the first case, the water goes into the drain holes on its own, this happens slowly and requires at least some slope of the roof. In the second, the liquid is literally sucked into the drain system due to the presence of siphons.
For a flat roof, IR heating and a combined system are suitable. Pipe sections are wrapped in film drain system so that they do not freeze, and the cable is mounted on the roof surface in several places. Or pipes and roofing on the underside are equipped with IR film. Maximum system power is required.
Installation of anti-icing systems requires training, special skills and strict adherence to safety precautions. This may turn out to be more difficult than expected, so it is better to entrust the work to professionals. If you already have minimal skills in working with electrical equipment, you can connect the system yourself. Installation is carried out in three stages: calculation activities, preparation and installation itself.
Project development is the first thing you need to tackle when installing a heating system for the roof and adjacent elements. Since installing electrical equipment on a roof is a potentially unsafe home improvement, it must be recorded on paper. With absence project documentation the change will not be considered legal and will become a hindrance when trying to sell the house.
The project is being developed step by step:
Ready project must contain information about how the heating elements are located on the roof, what the total power of the system is, where the RCD is located, whether the requirements of the rules for electrical installations and fire safety measures are met.
The roof area is measured based on its shape. Each side of the slope (if any) is measured separately, and at the end it is summed up into a total number.
Cable laying principles:
It is important to take into account the slope of the slope and the type of roof. On cold roof with a slope of no more than 15 degrees, heating the drainage system and cornice is sufficient. As the slope increases, the area that needs to be heated also increases. Along the edge of the cornice, the cable is laid in a snake pattern to a height of up to 40 cm. The step at which the cable is rolled up is 10-15 cm for single-core cables, about 30 cm for double-core cables. The distance between zigzags recommended by the manufacturer must not be exceeded.
If the roof is warm and flat, the cable is laid along the edge to a height of 30 cm, as well as along drainpipes. If the roof slope increases, the risk of ice melting increases, so the heated area also increases. The maximum permissible heating zone width for a flat roof reaches 50 cm.
The flat roof is heated along the edge and the water drainage system is heated. If necessary, lay the cable in the center. The width of the heated surface is 30-40 cm. The cable is laid around the drain funnels so that in any direction from the hole it is no shorter than 50 cm. The end is looped inside the drain hole to the level where the air temperature is already above zero.
For a roof with a slope of more than 45 degrees, heating along the eaves is not required. It is so steep that the snow will melt before it freezes. For such a roof, only the drainage elements are equipped with heating elements.
In places where snow accumulates. In problematic areas, the cable is installed in small increments so that the entire surface is heated and no ice remains. Difficult areas include places where parts of the roof slope meet: valley and drainage edges, places where the slope adjoins a vertical surface. According to the height of the valleys, it is enough to lay a cable snake 2/3 of the length. It is important to take into account that in places where it abuts the wall you need to retreat at least 5 cm from it.
It happens that the roof structure does not have water drainage elements as such. If there is no drain, the cable must be fixed along the very edge of the roof using a method called “dripping loop” (for a slope of 15-20 degrees) and “dripping edge” (less than 15 degrees, flat roofs). The hinges are installed with an allowance of 50-80 mm with the expectation that melt water will flow to the ground along them.
If there is a gutter, then the cable is laid both above it, along the edge of the roof, and in it. Inside the gutter it should lie in two or three parallel lines, without zigzags. The end of the cable should loop into the drain. You also need to fix a heating coil inside the drain pipe.
One of the most complex tasks when creating a project, calculate the length and total power of the cable for thawing ice.
The length consists of all the elements that need to be heated. Different roof areas may have different areas. For example, To calculate the heating of the gutter and pipe, you will need to perform several steps:
Lastly, choose the components: fastening elements and a suitable control unit. Then the location of the block is determined. It should be protected from moisture and sun, but located in an accessible location for manual restart repair if necessary.
For fastening, metal and plastic clips, glue, and sealant are used. It is better not to use metal fasteners.
At the preparation stage, two important tasks are solved:
Both professional installation and DIY installation are carried out in the same stages:
At this stage, you need to install mounting boxes, “ring” the heating cables to check the integrity of the cores, and measure the resistance.
In order for the system to work for a long time and correctly, it is important to observe some subtleties during the installation process:
Tips for extending service life:
Selecting heating systems on your own can be an overwhelming task. It is difficult to figure out whether you need a resistive or self-heating cable, a thermal or infrared system, and whether there is a difference between anti-icing and anti-icing cables in roof heating. Errors are not critical, but they lead to installation difficulties and increase the cost of system maintenance per season. It makes sense to purchase ready-made kits.
There are still few manufacturers of anti-icing equipment for roofing on the domestic market. But several brands have already gained trust. Among them:
Among domestic producers speak positively about the products of the company “Thermal Systems”, “Term” and “SST”.
The cable heating system for roofs and gutters is an anti-icing system, which is based on the use of electric heating cables to melt snow and ice on the roof and in the building's drainage system during dangerous periods - at a time when daily temperature changes 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 drains due to ice and snow accumulated in them.
Since the cable roof anti-icing system prevents the formation and, accordingly, falling of icicles onto the adjacent territory, it is classified as a safety system.
It is quite natural that in 2004 a document of the Moscow Committee for Architecture appeared, “Recommendations for the use of anti-icing devices on roofs with external and internal drains for residential and residential buildings under construction and reconstruction.” public buildings” which directly recommends installing such systems on all new buildings.
Currently, several thousand buildings in Moscow and St. Petersburg are equipped with cable roof heating systems. We have accumulated significant experience in design, installation and operation.
A properly designed and competently installed cable roof heating system with high-quality components prevents ice accumulation and ensures the removal of melt water along the entire route. As a result, the roof itself lasts longer, gutters do not sag, gutters are not deformed, and people and cars in the vicinity of the building are not threatened by falling icicles.
The following classification seems to us most successful:
Heating cables for use on the roof are subject to increased requirements:
Resistive cables and self-regulating cables are used as part of heating systems for roofs and gutters.
The advantages of resistive cables include low cost and stable power characteristics. The disadvantages are the inability to change the lengths of sections and the likelihood of overheating. On soft (surfaced) roofing coverings Resistive cables cannot be used.
Resistive cables for roofing
