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The climate of Our Country likes to present surprises in the form of cold snaps with heavy snowfalls and unexpected thaws. But even with a stable “minus”, icicles hang from the roofs that can cripple people. Timely installation of a modern anti-icing system can prevent this danger.
Causes of ice on the roof
“Temperature swings” inevitably lead to the formation of ice. This is the name of the weather with a temperature that changes from plus to minus at least once a day. In late autumn, early spring, and even winter, this happens regularly. The snow on the roof melts slightly and sticks together, forming the so-called “firn”, and then pieces of ice. Gutters are clogged to the top, water flows over the edge and now a bunch of icicles hangs from the roof.
Where does ice accumulate the most?
The coldest place on the roof is its edge protruding beyond the wall of the house. Gutters are usually laid there, designed to collect rainwater and drain it through funnels and downspouts to ground level. Ice forms and accumulates right here, on the edge of the roof and in the drainage system.
Why is roof icing dangerous?
Ice with its weight deforms the roof, bends and breaks gutters. The icy gutters no longer fulfill their purpose, ice covers them inside and out, the brackets do not withstand and break off. Blocks of ice crash down, breaking wires, breaking windows. In cities, ice floes flatten cars in the parking lot and kill bystanders.
In country houses and estates, icicles can cause serious injury to residents, destroy the roof and break objects near the house. Some homeowners park cars near their homes – needless to say, what can happen to a car after an icicle or ice floe hits it? De-icing is one of the most important tasks for owners of private cottages and dachas. And there is only one way to avoid this task becoming an annual headache.
How does the anti-icing system work?
Water always forms on the roof, even when it’s cold. After all, the house itself is also a source of heat, especially when its attic is used for household needs or as housing. The task of the anti-icing system is to prevent the moisture that has appeared from freezing. Water must leave the roof in a regular way through the gutter system, and this system must be free. However, continuous heating of the roof and gutters is irrational and will only lead to energy overruns.
The anti-icing system prevents the formation of frost, periodically turning on and warming the places of the most probable accumulation of ice. For this, heating cables, resistive or self-regulating, are used. Ordinary cables for underfloor heating are not suitable, they will quickly fail under the influence of water and solar ultraviolet radiation – cables in a special design are used for roofs and gutters.
Mechanical systems
The term “mechanical” when applied to anti-icing systems does not mean that you have to remove frost with a shovel. And you will have to turn the heating on and off manually, guided by the readings of the street thermometer.
Advantages and disadvantages
Automatic systems
An electronic thermostat provides XNUMX/XNUMX monitoring of temperature, humidity and water on the roof and in gutters. It works autonomously, receiving information from sensors installed in the coldest places on the roof and where excess moisture forms.
Advantages and disadvantages
Electric current resistance in cables is always tried to be lowered, but heating cables use this physical phenomenon to good use.
What is a heating cable?
Heating cables are one or two cores enclosed in a special sheath. It is durable, does not disintegrate under the influence of moisture, temperature and solar ultraviolet radiation. Structurally, heating cables are divided into self-regulating and resistive.
The self-regulating cable includes two copper wires fixed in a special matrix with a gap along the entire length. The gap between the cores is filled with semiconductor paste, which changes the active resistance, following the temperature.
The resistive heating cable has a more traditional structure. Its conductors are simply heated by the electric current passing through them, without changing their physical properties. These cables are available in single or double strands. The first are laid in a closed loop and connected to the thermostat with opposite leads. Both cores of a two-core cable are connected to the contacts of the thermostat, and on the opposite side they are connected to each other and sealed. Thus, a closed electrical circuit is created.
What function does it perform?
The heating cable is the main element of the roof or gutter heating system to protect against accumulations of snow, ice and icicles. It is the heating cable that generates the heat necessary for this, eliminating the danger to buildings and people who can suffer from ice blocks falling from above.
What are the options to choose it?
It is recommended to analyze the conditions for further use. On a simple gable or flat roof, a self-regulating cable is sufficient. Roofs of complex shape with dormer windows, niches, gables should be heated with resistive cables connected and connected according to a previously developed scheme.
How to calculate the power of the heating system and the cable laying step?
The minimum heating power is 250 W/m2 of heated area. The specified level is achieved by laying the heating cable.
Roof needs power 150-300 W/m2. On the roof, the cable is laid with a “snake” in a strip with a width of 0,5 m and a step of 0,13-0,15 m. In particularly cold climates, two or even three lines of independent cables are used.
2 or more strands of cable with a power of 20 W per meter are placed in gutters and pipes.
Do-it-yourself step-by-step diagram for installing a roof heating system
The roof heating system is quite complex. It is advisable to divide the work into several stages. It should be remembered that this information is for reference only, and to achieve a good result, the work of specialists is necessary, from the design stage to the installation stage. In general, the whole process consists of the following steps:
- Places of ice formation are visually determined;
- The design of a roof heating system begins with the selection of a heating cable laying scheme, installation locations for sensors, terminal boxes and power cables supply to them, based on the characteristics of the room, the roof area and the specifics of ice formation on it.
- Equipment is selected and purchased based on the calculated indicators of the cable length, plus 5% for inlets, turns and descents.
- Drainage pipes and drainpipes are cleaned of leaves and dirt. They accumulate moisture and create conditions under which frost is formed;
- Cable routing is marked on the roof. It should be laid in a “snake” at the bottom of the roof, where the most snow accumulates, and secured with special clips. The places of their connection with the roof are treated with sealant.
- Cable segments lowered into pipes are attached to a galvanized steel carrier cable or chain. This prevents the cable from breaking if ice forms on it.
- Gutters and gutters are heated by one or two lines of heating cable. The heating cable is laid on the bottom of the gutter, the power cable is fixed on the edge of the gutter.
- All connections are made strictly in sealed terminal boxes. The supply voltage is also supplied there through power wires in a waterproof design.
- An iron cabinet is installed in the room, where thermostats are mounted and where the power cable is connected. From here, it is routed through sections of the heating system.
- During installation, it is imperative to comply with the rules of safety regulations and the rules for the operation of electrical installations.1. Preferably fire alarm equipment and RCD installation.
The main mistakes when choosing and installing an anti-icing system
Inexperienced craftsmen make the following mistakes during installation:
- Use cables and fasteners designed for underfloor heating in rooms. They are cheaper, but on the roof are quickly destroyed by water and ultraviolet radiation from the Sun. Cracks form in the insulation of cables, water penetrates into them, a short circuit occurs and, as a result, a fire.
- Places of installation of mounting clips are not treated with sealant.
- Incorrectly calculated step and places for laying the heating cable. The system becomes inefficient, energy costs rise along with icicles.
- Incorrectly selected sensor installation locations. As a result, ice continues to form, despite the cost of electricity.
- The cable in the downpipe is not attached to the carrying cable. If frost forms, the cable may break under its weight.
Popular questions and answers
Responds to topical questions collected by the editors Maxim Sokolov, expert of the online hypermarket “VseInstrumenty.ru”.
– the angle of the roof is less than 45 °, and a lot of snow accumulates on it;
– the roof has poor thermal insulation, due to which heat escapes through it and melts the snow accumulated on the roof, which leads to icing;
– during the day, temperature changes are observed on the roof, for example, under the influence of sunlight.
All this leads to icing of the roof and the risk of falling icicles, which is dangerous for people passing near the house. There are also negative consequences for the elements of the roof – it can be deformed under the weight of snow and ice.
Roof anti-icing system helps to solve these problems. But it is worth noting that they mount it together with a cable for heating gutters and gutters. It is in the complex that this solution will give the desired result.
It is known that the main cause of damage to roofs, drains and gutters is ice, which accumulates on the surface and carries its destructive effect.
Without an automatic roof heating system, you will have to constantly monitor the weather, clean the snow, knock down icicles, and defrost the drainage system. In a normal winter, such work is required several times a month, and in a very snowy winter, more often. If these chores are not for you, then it is better to install an anti-icing system and leave it to this task.
Sources of
- https://base.garant.ru/12129664/