As you know, winter in our country always starts unexpectedly. For this reason, frost and snow are a real disaster, which is accompanied by meter-long snow caps on the roofs and ice blocks hanging from the eaves of houses. Everyone struggles with unfavorable weather factors in their own way - some throw snow and icicles from the roofs, others simply fence the sidewalk with ribbons. Both are trying to deal with the consequences, while it is simply necessary to eliminate the cause. But this is not difficult at all - it is enough to equip the roof with a snow melting installation. In this article we will tell you about the features of the calculation, design and installation of anti-icing systems. And most importantly - about how to make it yourself, and even with minimal costs.
Everyone knows what harm to the health and property of people can be caused by massive icicles and snow layers hanging from the roof - unfortunately, the results of human sluggishness often led to tragedies. But the formation of ice is a rather serious threat to the roof.
The accumulation of ice in gutters, funnels and pipes reduces their cross-section, which makes it difficult to remove melted snow during a thaw. Water accumulating on the roof penetrates into the smallest cracks. Needless to say, what will happen with the next drop in temperature? The result is sad - the freezing liquid expands and tears the roofing. This cycle repeats itself many times, and the destruction grows exponentially. As for the gutters clogged with ice, they simply cease to function. Overflowing the edge, dirty water flows along the facade of the building, making it look unsightly and destroying the walls and foundation.
The accumulating snow is dangerous not only for people and the property below, but also for the roof itself.
Trying to prevent the described troubles, many owners of private houses remove snow and ice with shovels, scrapers, ice axes and other tools. This is not to say that this method has no right to exist. However, in this case, there is a danger that the roof itself will be damaged by physical impact, especially if it is covered with materials such as slate, soft tiles, ondulin, etc.
The author of these lines fell into a similar trap, trying to get rid of the snow on the sloping roof slope. Climbing upstairs with a shovel and a small homemade scraper, I began to remove the snow and scrape off the ice. Honestly, the work was arguing and was already nearing completion - all that remained was to remove the joint between the slopes. What was my disappointment when the unsuccessfully broken scraper broke through the valley, and even at its lowest point. Needless to say, all day until dark I was repairing the gutter, reproaching myself for such an oversight. However, as they say, there is no silver lining. Once I got a lesson, by the next winter I was fully armed - though a simple, but very effective snow melting system was installed on the roof. Since it pleases me with its reliable and economical work for the seventh consecutive winter, I consider it my duty to share my knowledge and considerations with those who are just studying this issue.
In order to eliminate the dangers associated with the accumulation of ice and snow, a structure of electric heaters is mounted on the roof. With its help, it is possible to solve a wide range of tasks:
Since the main function of the roof anti-icing system is to drain melt water, its contours often cover not only downpipes, but also the receiving funnels of the drainage system.
Dumping snow from roofs by hand is not a good idea - it can easily damage the roof.
In its simplest form, a structure for protecting the roof from snow and ice consists of the following parts:
More sophisticated systems can be supplemented with sensors that react to humidity and precipitation, a weather station, various programmers and safety devices.
The anti-ice installation includes not so many components, which makes it easy to assemble the structure with your own hands
The operation of the snow melting unit is provided by a thermostat. On a signal from the temperature sensor, it will turn on the heater every time the temperature drops below the set mark. Even an ignorant person will notice the imperfection of this design - the heating cables will turn on and burn electricity even when there is not a snowflake on the roof. For this reason, in more expensive systems, the power supply will not occur until the control unit processes a signal from another device - a humidity sensor. Heating will start only when the logic level is low, indicating the presence of ice. As soon as the signal device is in the water, the voltage supply will immediately stop - the main task is completed, and the inertia of the heaters will finish the job. Of course, such a system will work much more efficiently and economically.
Starting to calculate the electrical power of the anti-icing system, they draw up a roof drawing indicating the zones that need to be heated. After that, a heating cable laying scheme is applied to it and the total footage of the heaters is calculated. All that needs to be done to determine the maximum load is to find the product of the cable length by its specific power (the manufacturer must indicate the heat release of the heater per linear meter of its length in the technical passport).
Those who think that the heating cable will need to be laid over the entire surface of the roof are very mistaken.... The main task of the protective structure is to ensure the operability of the drain and eliminate conditions for the formation of ice and snow drift. For this reason, it will be sufficient to install the heaters in several places.
On flat roof surfaces, heaters are mounted with a snake
To heat the valley, a few strands of cable are enough, laid in its lower part.
Depending on the width of the gutters, you can use from one to four heater strings to heat them.
Often, a part of the circuit mounted in the drainpipe is sufficient to heat the drain funnel.
The heating cable is laid in loops and fixed to the pipe walls
While focusing on the above areas and structural elements, we should not forget about other places with increased heat generation. So, in order to prevent the formation of ice around the skylights, it is necessary to lay one strand of cable around the entire perimeter. The heater itself should be brought along the path of the melt water outflow - in this way it will be possible to simultaneously kill two birds with one stone.
The anti-icing system covers not only the surface of the roof, but also applies to all elements of the drainage system
So, the places for laying the heaters are marked. Now it is necessary to determine the length of the cable elements that will be needed to heat a particular area of the roof. You don't need to do any complicated calculations - we will use the data obtained in a practical way. For efficient and economical operation of the system, the following electric power values will be sufficient:
Taking into account these data, the scheme of laying all the contours of the "anti-ice" system is determined and applied to the drawing. In those places where a higher thermal power is required, the cable is laid with a snake or "shell" - it all depends on the type and power of the heaters.
A scaled drawing of the roof with applied elements of the snow melting system will simplify calculations and facilitate installation
Thinking over the laying scheme, do not forget about such a parameter of the electric heating cable as the minimum bending radius. Do not try to deform the heater more than is intended by the manufacturer. Due to the peculiarities of its design, excessive rounding can lead to damage to the insulation or breakdown of internal conductors and reduce the durability of the heating circuit, or even completely disable it.
The cable heater is the main component of the de-icing system. Outwardly, it has a certain resemblance to an ordinary electric cable, but it is given out by an increased diameter. The latter is due to both a more complex design and the need to use thick layers of insulation for maximum protection against external damage and high humidity.
Manufacturers produce heating cables of two types:
The former are notable for their extremely simple design, which does not prevent them from having a higher heat transfer. They are chosen because of the stability of characteristics, elasticity and relatively low price. The advantages of the latter are the ability to obtain more economical, reliable, maintainable and safe circuits. So that you do not have to make a choice based only on the pros and cons of heating elements, we will consider their design in more detail.
Resistive heating cables operate on the principle of ohmic loss in a conductor with high internal resistance. Their temperature reaches 250 ° C, which is explained by the high specific power - up to 30 W / m. Excellent technical characteristics allow the use of resistive cables where enhanced heating is required - in valleys, along the eaves, etc.
If the drainage system of your house is assembled from plastic pipes, funnels and gutters, then the maximum power of the heaters should not exceed 20 W / m. The same value of heat dissipation is taken for a roof with a soft coating.
Depending on the design, the resistance heater has one or two cores, placed in a heat-resistant fluoroplastic sheath. To eliminate the electromagnetic interference generated by the cable, copper braid or a solid screen of thin aluminum foil is used. The top of the structure is closed by a shell made of durable heat-resistant plastic.
The simplicity of the design of the resistive cable leads to its relatively low cost.
Knowing the device and the principle of operation of resistive heaters, we can learn a few useful points for ourselves:
The main difference between single and two-core cables is that the latter allow a connection scheme only from one edge. This means that much less power conductors are needed during installation.
Depending on the type of resistive cable, it can be connected in two different ways.
The live conductors of the self-regulating heater are in the environment of a special thermoplastic. Unlike ordinary plastic, its structure includes not only molecular chains, but also graphite grains. It is they who provide heating, turning the structure into an electrical system with many parallel resistances. And that is not all. The point is that the conductivity of graphite inclusions strongly depends on temperature. When it rises, resistance increases, and accordingly, heating decreases. Conversely, a decrease in temperature provokes an increase in current strength, thereby increasing the heat generation of the cable. That is why it is called self-regulating.
Heat dissipation of a self-regulating cable occurs due to heating of the polymer matrix
The most important advantages provided by the design of high-tech tape heaters are stable characteristics and the ability to use sections of any size. This type of cable does not overheat when overlapped and does not burn out in case of minor damage. For a long time, self-regulating heaters were inferior to resistive ones in terms of heat transfer and maximum temperature, but today there is no reason to talk about the significant superiority of the latter.
Based on my own experience and as the author of this article, I recommend that even at the design stage of the anti-ice system provide for the use of electric heaters of both types. Installation of resistive cables should be carried out in open areas - along eaves, on gutters, around roof windows, etc. Self-regulating elements will be useful where there is a risk of local overheating - in pipes, funnels and gutters. Thus, you will solve three problems at once: make the structure as efficient as possible, ensure its durability and get the opportunity to save energy.
Having decided on the type of electric heater for each circuit, you can begin to determine the electrical power. It is not difficult to do this - it is enough to multiply the length of the cable by its power density. So, when using 80 m of a resistive heater with a specific power of 25 W / m and 60 m of a self-regulating cable with a thermal efficiency of 15 W / m, the load on the electrical network will be (80 m × 25 W / m) + (60 m × 15 W / m) = 2900 W = 2.9 kW. In the future, this parameter will be needed when determining the cross-sections of power conductors, as well as when choosing protection and switching devices.
As the ambient temperature rises, the heat dissipation of the self-regulating cable decreases
After selecting the heating cables and performing the necessary calculations, you can proceed to the selection of other components of the anti-icing system. If you are going to build a budget structure on the roof, then prepare the following components.
The easy-to-install snow melting thermostat can be installed outdoors by placing it in a sealed enclosure.
|Heating circuit power, kW||1||1,2||1,5||1,8||2||2,5||3||3,5||4||5||6|
|Consumption current, A||0,46||1,36||2,28||3,18||9,1||11,4||13,7||15,9||18,5||22,8||27,3|
|Stranded conductor cross-section, sq. mm||0,75||1,0||1,2||1,5||1,5||2,0||2,5||2,5||3,0||4,0||5,0|
If the budget allocated for the anti-ice installation allows you to purchase a control unit together with moisture and precipitation sensors, be sure to use this opportunity. The additional costs will pay off in the first two years, because such a system will be more economical.
The set of a complete, but at the same time quite budgetary system of snow melting consists of a control module and temperature and humidity sensors
Modern controllers of anti-ice installations include a whole weather station, and the most advanced of them can connect to the Internet. These capabilities allow implementing an intelligent control scheme, which significantly increases the efficiency of the system, makes it as economical as possible and contributes to the durability of all components.
Before starting the installation work, you should clean the places where the heating cable is laid from fallen leaves and other debris. After that, it is necessary to inspect the roof and identify the dangers that lie in wait for signal, heating and power cables. Protruding fasteners, bent edges and sharp edges of the roofing can damage their shell, so all defects should be eliminated.
The anti-ice system is installed according to the following algorithm.
Precipitation and humidity sensors are installed on open horizontal sections of the roof slope
For fixing heaters and wires on the roof, special mounting strips are best suited, which, if necessary, can be turned into clips of the required length
On sloping roof slopes, the heating cable should be fastened in a zigzag manner, observing the pitch and width of the installation
If the cable is long and heavy, it is attached to a cable or chain laid inside the pipe.
All cable connections must be made inside sealed junction boxes and reliably protected from moisture ingress
While assembling your own de-icing system, your humble servant made one very big mistake. Collecting information on the network on how to fix a heating cable, I became interested in a rather interesting way using a metal mesh for reinforcing reinforced concrete structures. Numerous attachment points made it possible to quickly lay the heater and fix it with plastic ties. Having secured the sections of the construction mesh at the gutters, I was happy with the speed of installation. Disappointment came in the fall, when inspecting the system ahead of next season. The mesh served as a kind of filter, collecting a three-centimeter layer of fallen leaves, branches, dirt and other debris in its cells. In order not to expose the heater to the danger of overheating, several circuits of the system had to be dismantled and re-installed. Perhaps, for the roofs of houses far from forest park areas, this recommendation will be superfluous, but if tall trees grow nearby, it is better not to risk it.
All that remains is to check the correct installation and conduct a test switch-on. This is best done under suitable weather conditions. If precipitation is not expected in the near future, then you can pour water on the sensors installed on the roof. For testing, a current clamp is used - with their help, the current of each section is measured and conclusions are drawn about its performance. Troubleshoot if necessary.
The snow melting system is a self-sufficient design, therefore it works in an automatic mode and does not require regular intervention. At the same time, it is very easy to ensure the efficient and durable operation of a self-assembled installation - just follow a few simple rules.
Casual people should not be allowed to service the structure - it is best to do this work yourself. The fact is that no one knows better than you about the peculiarities of fastening all elements of the snow melting system on the roof. It is for this reason that you can be sure not only of the operability of each circuit, but also that the roofing will remain intact.
The snow-melting and anti-icing system built in accordance with all the rules will protect your family and protect your property from ice and snow falling from the roof. In addition, the timely removal of melt water will make the roof more reliable and durable. From now on, you will forget about high-altitude work with a shovel and an ice ax at the ready. And this is correct, because free time, and even in a snowy winter, can be spent much more interesting, right?
The roof heating system is used to prevent ice plugs in the drainage system, providing a channel for defrosting water that is heated to the required temperature. On average, for effective heating 1 running. m of drain requires a power of 30-60 watts. Gutter heating is an excellent solution for both private and industrial facilities.
The valleys and abutments of the roof are areas of increased risk of snow accumulation. If an ice block forms in the lower part of these zones, melt water begins to rise upward, damaging the waterproofing on its way and penetrating into the room. The roof heating system prevents this process, which, among other things, entails expensive roofing repairs. It is considered sufficient to heat the valley by ½ of its length with an average cable power of 40–60 W / running. m.
On the surface of the so-called "warm roofs", the feature of which is low-quality thermal insulation, one can observe a large accumulation of snow and ice on the lower part of the roof. Due to poor thermal insulation, the snow cover on the roof melts and "slides" to the lower part of the roof. In this case, experts suggest using cable heating of the roof, installed on the lower slope (distance from the edge of the roof - 0.4–0.5 m). The average power of such heating should be at the level of 200-250 W / m². To exclude the likelihood of the descent of masses of snow and ice, special snow retention elements are installed.
Heating of gutters can be supplemented with cable heating of the ground drainage system, which can be located in the zone of soil freezing. Heated drainage is a guarantee that there will be no ice accumulations on the concrete blind area and the water will be fully drained into the well.
In some cases, a roof heating system involves installing a cable in the drip zone, on which icicles can form. Dripper heating is especially important for buildings with gutters that are installed directly on the roof slope.
Roofs with internal drainage need to be heated with funnels, ice plugs in which can lead to water congestion.
In recent years, our winter has been unstable: thaws are often replaced by frosts, frosts - thaws. Due to such weather "swings", the appearance of icicles on the eaves and ledges of the walls is inevitable, as well as icing of gutters. When designing houses, architects usually take this issue into account. However, constructive construction solutions can not always completely eliminate the causes of ice formation.
Modern Icicle Control
The simpler the roof profile and the greater the angle of its slopes, the less chances for ice. The nicest thing is a simple-shaped roof with a slope of at least 30 °. The presence of a cold, ventilated attic and the absence of gutters also reduce the chances of an "ice age". And here are dormers, balconies, turrets, internal gutters (valleys), etc. in the literal sense, water is poured into the mill for the formation of a snow cover on the roof, the harmful and dangerous consequences of which you do not need to tell.
Skylights, balconies, turrets, internal gutters (valleys), architectural details literally pour water on the mill for the formation of snow cover on the roof and other structures
Accordingly, all these architectural and construction details contribute to the appearance of ice and icicles on the roof and drainage systems.
Frost does not form constantly in cold weather, but in February-March, when the air temperature jumps from +3. +5 ° С during the day to -6. -10 ° С at night. That is why the operating mode of the systems in question is set at a level not lower than +5. -15 ° C.
there is two reasons for the appearance of ice on roofs and drainage systems:
The consumption of heat through the floors of the house and the roof leads to the fact that the temperature of the central part of the roof becomes higher than the ambient air temperature. At the heart of this "trouble" is the weak heat protection of the under-roof space and zero roof ventilation. Melting snow on the slopes gradually slides, and melt water freezes on the roof overhangs blown by the wind, forming ice and icicles and clogging the drain.
Melting snow on the slopes gradually slides, and melt water freezes on the roof overhangs blown by the wind, forming ice and icicles and clogging the drain
Water congestion on the roof in inclement seasons leads to leaks, damaging the upper floors of houses and fragments of facades near gutters and valleys. It becomes damp in the under-roof space. This invariably increases the thermal conductivity of the insulation (the opposite of the desired result) and provokes the appearance of fungi and mold on wooden rafters.
Ice in the gutters not only deforms, but can even destroy the elements of the drainage system. Who among us has not seen broken gutters and ice-torn pipes? Icicles hanging on the eaves of the roofs not only spoil the appearance of the house (you can still put up with this for a couple of harsh weeks), but also threaten the lives of the owners and bystanders.
Icicles hanging on the eaves of the roof not only spoil the appearance of the house (you can still put up with this for a couple of harsh weeks), but also threaten the lives of the owners
The most efficient way to deal with this problem is to use cable de-icing systems... This method is widely used in northern countries. Its meaning is not in the fight against the already formed ice, but in preventing its formation.
Prevent water from freezing on the elements of the roof and in the gutters, ensure the possibility of its drainage through the gutters into the storm sewer - the main task of the cable de-icing system... Agree that heating melt water will require less heat input (energy consumption) than melting ice.
The essence of cable de-icing systems is simple: a heating cable is laid on roofs and in drainage systems.
For flat tiles, special cable clips are provided. Photo: profstroy33.ru
When connected, it heats up, the snow lying next to it melts and does not turn into ice, but flows from the roofs along the gutters.
The cable heats up, and the snow lying nearby is melting. Photo from icedamcompany.com
And there are already installed their own heating cables. The main thing is not to let the water freeze.
The system includes heating cables, power wires, sensors, control panel, junction boxes and hardware. Electric cables are powered from a household network with a voltage of 220 V. If so, then when designing and installing the system, it is necessary to follow the requirements of the Electrical Installation Rules (PUE). You will find them in the article Ordinary conventional electricity.
In addition to overload protection, the power supply system must necessarily include insulation monitoring sensors or a residual current device (RCD). All this, together with a grounded heating cable braid, will provide complete electrical safety anti-icing installation.
The operation of the cables is "controlled" by an automatic thermostat, which removes the necessary information from the sensors installed on the roof - temperature, relative humidity, the presence of water on the roof.
Switching diagram of individual elements of the system. Photo: evrolain.com.ua
After receiving signals about climatic conditions provoking the formation of ice, the thermostat gives "the go-ahead" to turn on the electricity through the loops of the heating cable, which begins to warm itself and generate heat. In good weather, the thermostat automatically turns off the heating. Here it must be borne in mind that excess overheating is thrown away money, which may still be useful to you.
The described situation is aerobatics, implying 100% completeness of the heating system. But you can save a little: give up sensors and a thermostat and control the system in manual mode.
Cable heating equipment set comprises:
There is no reason to lay the heating cable exclusively along the edge of the roof and not to heat the drainpipes: the melt water will drain from the roof, but once it gets into the cold drain it will freeze right there.
This picture was taken by the author in Norway. There is not a single downpipe without a heating cable. An overabundance of waterfalls gives this country cheap electricity
Heating is especially needed on complex elements of the roof: at internal corners, near protruding structures (lamps, pipes, skylights, etc.), as well as on flat areas. On flat roofs and roofs with a low slope (up to 30 °), the heating cable is usually laid either over the entire surface (how much electricity will "run" here!), Or on receiving gutters and areas adjacent to the gutters.
The electric cable is laid along the edge of the roof, inside the gutters and lowered into the gutters along the inner surface of the pipe and funnel. At the bottom of the drainpipe, on the cut-out spout, the wire is made in the form of a loop.
Installation of heating systems for pipes and roofs. Photo from soldim-heating.ru
On the eaves, the heating cable is placed exactly along the edge. If you do not follow this recommendation, the cable will melt the snow, but the melt water, reaching the cold edge of the roof, will freeze and turn into icicles. The effect will be the opposite, and taking into account the cost of electricity - negative.
In order to fix the cable in the desired position and eliminate tangling and overlaps, special clamps and fasteners are used.
Cable heating of the gutter. Photo from the site otopim-dom.ru
Design capacity of the system depends on:
Let's say a horticultural partnership allocates 6 kW to your home, that is, 6000 watts. Let's reserve one kilowatt for the refrigerator, TV and emergency lighting. So you have 5000 watts to warm up your work cables. Divide 5000 W by 50 W / 1 meter. We get 100 m of cable. Thus, you can operate with a cable length of 100 meters. Now calculate the perimeter of the roof and the length of the downpipes of your country house. For a modest cottage, this cable length may be enough.
It should also be remembered that this “squandering” of electricity, aimed at combating objective natural phenomena, lasts a hundred or two hours a year.
Main technical parameter of cable - power per unit length. In other words, it is important how much heat one running meter of the cable will release.
Heating cables. Photo from icedamcompany.com
Additional requirements for outdoor work are also very strict:
A single-core cable is connected to the mains from both ends, a two-core cable from one. At the other end, a plug is placed that connects the heating and connecting conductors. The choice of cable type depends on the area and configuration of the roof sections to be heated.
The main drawback of resistive cables is the constant resistance along the entire length, and therefore they heat the same everywhere. This leads to unnecessary energy consumption, since the heat transfer conditions over the entire length of the cable can be different.
For example, the foliage that has flown from the trees and covered with itself a part of the cable noticeably changes the thermal engineering conditions of this segment. Therefore, in some areas, the resistive cable will overheat, and this will unreasonably increase the cost of its operation. And under the foliage, it can even overheat and burn out. Such a cable requires constant external control and maintenance: for example, cleaning branches, fallen leaves and other debris from the roof.
In addition to resistive, there is also self-regulating cablesthat automatically change heat generation depending on the ambient temperature and are able to economically consume electricity. Moreover, this property is local: each section of the cable reacts to the conditions surrounding it.
This is truly high technology. Without going into them, I will say that between the two current-carrying conductors there is a heating element connected to them - a polymer matrix with a conductive filler. The latter has a high coefficient of thermal expansion. Therefore, when it gets cold, the material of the heating element of the matrix shrinks, its resistance decreases, and the amount of current passing through the matrix increases. Of course, heat dissipation immediately increases. And vice versa: as the air temperature rises, the resistance increases, and the amount of heat decreases, which prevents overheating. Such a cable is not afraid of the cover of last year's leaves.
The choice of this or that type of cable depends on the characteristics of each roof and the financial capabilities of the owner of the house.
Not everyone can design and install a cable de-icing system on their own. This is especially true for electrical safety issues. Analyze the situation, carry out a competent calculation of the system, choose high-quality material and reliable equipment - this requires the experience of professionals or gifted Kulibins. Please note that:
The spacing between the fasteners should not exceed 300-350 mm. It is required to ensure that the cable lines do not come into contact, let alone intertwine with each other. At the beginning of autumn, a test run is carried out to check the readiness of the system for operation in the cold season.
Installation price anti-icing systems vary widely depending on the materials and equipment used, the operating mode of the control system and the characteristics of the roof. You can choose a suitable system on our market, where offers from the largest online stores are collected.
Expensive systems are characterized by increased reliability and last longer, and, most importantly, they can significantly reduce energy consumption. After all, the cost of paying for electricity - the main disadvantage of cable heating... Although it largely depends on the prudent and careful supply of voltage to the heat cable.
Subject to proper design and installation, the use of roof de-icing systems based on heating cables will allow you completely eliminate the formation of ice and ensure the operability of the drain... And most importantly, the roof will remain intact, regardless of the vicissitudes of the weather and climate.
The main function of the snow melting system is to empty the drain pipes for melt water. At any temperature, the liquid must move along the drains. Electric heating continues until the snow melts completely.
Factors Affecting Snow Melting:
But there are other factors of influence as well. But the principle of operation itself is quite simple. The system must first analyze all temperature and humidity readings. After that, the optimal mode is determined and heating starts. This saves electrical energy. This aspect is quite important, because the total power of the cable can be quite large.
For the system to work properly, it is necessary to select high quality materials and carry out the correct calculation.
After determining the air temperature, a timer is turned on for a certain period of time. When this period has passed, the liquid and precipitation sensors are triggered. With excess snow, the heating of the roof and gutters starts. When the precipitation has passed, the roof itself stops heating, but the functionality of the pipes and trays remains active. This is done so that the flowing liquid cannot freeze in the drain. The entire operation of the system is fully automatic, which is quite convenient for the owner of the house.
In order for the anti-icing system to cope with its task, it must have sufficient power, which must be determined by the specialist of the installer. In the Kiev area recommended power of cable systems is 30-50 W / m. n. - for narrow trays and drainpipes, 50-100 W / m. p. - for wide gutters, 10-30 W / m. etc. - for roof slopes and valleys. The last figure depends on the composition of the roofing "pie": the better its thermal insulation characteristics, the less heat inside the house passes through it and the less power of the system can be designed.
Of course, the higher the power of the cables in the system, the higher its total cost. However, it is not recommended to reduce the power indicators below the required ones, otherwise, in a situation where there is a sharp cold snap after a daytime thaw, the structure may not cope and will rather help the formation of ice than "wash" the snow from the coating. So that it is better on the contrary - install cables with a power reserve.
The anti-icing system must be installed qualified specialists, which on the spot will preliminarily determine the most dangerous zones of the roof and make the measurements and calculations necessary for installation. Just laying the cable in a trough or pipe is not enough, it must be fixed with clips made of plastic or galvanized steel... When fastening the system, it is unacceptable to violate the integrity of the upper layer of the roof. Rivets are used only for gutters in places where it is indispensable. On top of the metal tile, it is better to first glue the rubberized fabric, to which the cable is hooked. But on natural tiles, ice practically does not form, and here the system is usually laid only in gutters. In valleys and downpipes, cable fasteners are usually suspended from a metal cable so that the melting ice does not hang on the thermal cable and break it.
It is better to trust the installation of companies that will provide warranty and post-warranty service, and also have a state license for the installation of electrical equipment and a fire safety certificate for electrical equipment.
After installation, the owner must provide system data sheet, working drawings and acceptance certificates. The latter should only be signed after checking the system. Once every 2-3 years (or better annually at the beginning of autumn), it is worth calling a service specialist who will inspect the external state of the heating sections, tighten connections and contacts if necessary, and also test the operation of the control automation.
The electrical safety of anti-icing systems is ensured by the presence of a shielding braid and reliable cable insulation. At the same time, on the roof, the latter is exposed to a sharp effect of high temperatures and ultraviolet radiation, which provokes the disintegration of the polymer coating. Therefore, reliable materials with a good protective shell are used here. The lead-in cable is laid in a weather-resistant metal sleeve to protect it from mechanical damage during roof maintenance. In addition, all supply lines must be equipped with a residual current device (RCD).
You can also find out the approximate cost of the system by phone, for which you should tell about the length of the gutters, the surface area occupied by the house, the angle of inclination and the material of the roof covering. For a full-fledged calculation, it is necessary to know not only the length, but also the number of downpipes, trays, valleys, etc. about $ 500 e. A similar project with automated control of heating the roof and gutters will cost about 1,000 cu. That is (both in the first and in the second cases, resistive cables are provided, not self-regulating cables).
On the modern market, you can find many different proposals, despite the fact that this attribute for the arrangement of a country house appeared in our country quite recently. And since it should be admitted that there are few people who have heard of gutter manufacturers, we will consider the most popular of them, taking into account the characteristics of their plastic gutters, customer reviews and the price category to which they are located.
Gutter system components
Docke gutters are standard products. At an affordable cost, the quality of the materials used will delight even demanding users. Of course, it is difficult to provide the cost of at least one ready-made kit, since it all depends on the size of the house, the step and the number of fasteners used. However, it is quite possible to consider the prices of individual elements of Docke plastic gutters:
As you can see, these are economy class goods available for purchase to everyone. There are practically no complaints or significant criticism among customer reviews. The Alta Profile gutters belong to the same price category.
Plastic gutters from the French manufacturer Nicoll are middle-class products, which are characterized by an attractive appearance and rather high quality of each component. But such purchases are no longer available to everyone, since the cost, for example, of a 4 m long gutter will be about 920 rubles, and one funnel will cost 850 rubles.
Plastic gutters from the manufacturer Nicoll are represented by a wide range at an affordable price
At the same time, the choice of models is very large, so there is an opportunity to choose the right option for any home, regardless of the design style and materials used.
It is impossible not to mention the classic gutters made by Marley. This is a great option for those who strive for original design solutions and at the same time are ready to pay a considerable price for such an element as a gutter.
Of course, it makes no sense to buy plastic roof gutters, the price of which is so high, if the design of the house is quite simple. In this case, the usual models will be enough, which will not be inferior to Marley in quality, but will cost much less.
Important! The price of a heating cable for roofs and gutters, the importance of the installation of which will be discussed later, may also differ depending on the manufacturer.
Step by step, we will consider how to install gutters.
Gutter brackets. (photo # 5)
We can use brackets made of metal and plastic. The choice is determined by what the gutter is attached to.
Metal brackets - if the gutters are attached to the rafters.
How do I mount them? First, we install the extreme elements 15 cm from the end. A gap of at least 2 cm must be provided between the frontal board and the bracket.
Pull the cord between the installed brackets. Along it, at a distance of 60 cm from each other, we fix all the other brackets. Important: there should be a slight slope towards the drain. It is optimal if it is 3-4 mm per 1 running meter.
Plastic brackets can be used if the gutter is attached to the frontal board. But first we check that it is installed vertically, evenly, without curvature. In the same way, you need to double-check the brackets that will be attached to it. The quality of the entire system depends on this.
Like metal brackets, first we fix the plastic brackets approximately 15 cm from the end of the gutter. We pull the twine, along which, using self-tapping screws, we mount all other brackets with a step of 60 cm. It is also important to provide a slope for the natural movement of water towards the pipe.
Installation of a gutter. (photo # 6)
We insert the groove into the brackets one by one. In this case, you need to press until it clicks.
The hole for the funnel must be cut in a solid gutter (installation of the funnel in a fragment of the gutter is not allowed).
The funnel is installed in the right place. With a pencil, mark its size. Then we cut a corresponding hole in the gutter. For this, it is convenient to use a bimetallic bit. You need to work at low speeds.
We remove burrs on the edge. We cling the edge to the rear edge of the gutter and start it behind the front. In this case, a characteristic click will be heard.
The place where the funnel is installed must be reinforced on both sides with brackets.
The mesh is installed in the funnel hole. This is an optional, optional step.
As the temperature changes, the plastic elements expand and contract. Therefore, they should not be joined too tightly. For this purpose, on the reverse side of the Alta-Profile coupling, a special restriction with the inscription “Stop” is provided.
We hook the edge of the coupling onto the rear edge of the gutter. Then we start the leading edge over the edge in front. A characteristic click will be heard.
To give the system strength, we install additional brackets on both sides of the coupling.
We install the brackets as close to the corners as possible. Insert the edge of one groove into the corner element, then the second - until it clicks.
An alternative is to use an adjustable gutter angle. The application method is the same as we used the universal 90 degree angle. First we insert the gutter, then we adjust the required angle and insert the second gutter, until it clicks, but no further than the bounding mark with the inscription “Stop”.
Fastening the plug. (photo # 8)
There are special tendrils inside the plug that fix it firmly on the gutter. With their help, we fix the plug.
Pipe elbow. (photo # 9)
Install the pipe bends in the direction of the drain, so that the slope angle differs from the vertical position.
Pipe installation. (photo # 10)
Insert the upper edge of the pipe into the elbow socket. We fix the pipe to the wall using clamps, which we place 180 cm (or less) from each other.
To keep the pipes vertical, you need to make sure that the brackets that hold the gutters are also installed vertically, without deviations.
Only in the lower part, the pipe can deviate slightly from the vertical, but in the direction opposite to the wall of the house.
Install the upper clamp under the downspout elbow.
To do this, bend back part of the clamp and thus open it. We insert the pipe until it clicks and fix it. We snap the clamp and fix it with a self-tapping screw.
To connect two pipes in length, we use a coupling.
The drain is installed at the bottom of the pipe. We fix it with self-tapping screws.
The work has been completed. Now you know how to mount a plastic gutter. The metal gutter system is installed in the same way, but with some nuances.