What is roofing material for and how to choose the right roofing material. What roofing material is best for a roof? The main types of roofing material and their application

To date, a roofing material roof is no longer as popular as it was 20-30 years ago, but still such a roof is arranged over small country houses, garages, outbuildings, etc. At the same time, roofing material for the roof must be chosen no less thoughtfully so that finished roof served its cherished 10-15 years. Especially when you consider that the roofing felt has undergone significant changes in production since the Scoop. In the material below, we will analyze how to choose a roofing material for a roof and by what principles it is classified.

Ruberoid is called dense roll material, used both for roofing roofs and for waterproofing works when constructing a foundation, floor or basement. The bituminous coating is based on a special cardboard, the density of which can vary from 300 to 500 g/m2. Moreover, the greater the density of the base, the more durable the material will be. In the production of bituminous roofing, cardboard is impregnated on both sides with oil mastic, and then treated with refractory bitumen. To strengthen the lower and upper layers, stone chips are poured over the impregnation. Here, depending on its type and fraction, roofing material is classified primarily.

Important: in addition, bituminous material is divided into lining and top.

Types of roofing material

Types of bituminous coating are distinguished by the type of fraction of the upper stone layer. So, there are such types of roofing material:

• Lining. In this case, bituminous roll material is used, having one- or two-sided dressing of fine-grained sand or powdered (talc) dressing. The thickness of such coatings, as a rule, is from 3 to 3.5 mm. Both of these types of roofing material can also be used as a waterproofing material.
• Roof top. Here we are talking about roofing material for the roof of the house, which is laid as the top layers. roofing. As a rule, this is a roofing material with dust-like crumbs on the underside, and with coarse-grained ones on the top. It is also possible to use a bituminous coating with a slate scaly top as the top material. The upper roofing material has a thickness of 4.5-5 mm.
• Universal. It has only the upper coarse-grained coating. It is used both as a lining material and as the top layer of roofing.

Important: spraying in roofing material serves as the main protection against moisture, cold, ultraviolet radiation and mechanical influences. In addition, it is this layer that makes it possible to avoid gluing the coating in the state of the roll.

Types of roofing

There are also different types roofing material, which are classified according to the type of coating composition. So, there are such types of material:

• Tol. Progenitor of roofing material from the time of Scoop. Previously, only they covered the roofs of high-rise buildings. Here, during production, the cardboard base is impregnated exclusively with coal or shale substrate, and then the roll is sprinkled with stone chips on both sides. This type of coverage is universal.
• Euroruberoid. A bituminous material with a fusible bottom layer, which allows it to be laid simply by heating or lightly dissolving with white spirit. The basis of such a coating is not just cardboard, but fiberglass or polyester, which enhances strength characteristics roofing material.
• Rubemast. Here, the coating also has a fusible bottom layer, which seizes with the crate when heated or treated with a solution. It is believed that roofing material laid in such ways lasts much longer.
• Glass roofing material (glass mast). It is based on fiberglass. As well as roofing felt is universal.

Advantages and disadvantages of roofing material types

It is worth knowing that a roofing material is not always a durable construction. Moreover, its service life depends on the type of material used. However, the main advantage in any case is the low cost of roofing, including the full cost of the purchased material. So, consider the disadvantages and advantages of each type of coating.

Tol

The advantages include:

• Favorable cost;
• Comparative ease.

• Short service life (about 3-5 years);
• The fragility of the material over time;
• The need for laying up to 5 layers of coating.

In general, such a roofing material is not the best, but the cheapest option.

Rubemast

This type of material already significantly outperforms roofing. Its advantages include:

• Long service life (about 15 years);
• Good plasticity;
• Frost resistance (can withstand up to -15 degrees and does not crack);
• No need to buy bituminous mastic for its installation.

Important: due to the thicker bottom layer, this material can only be laid in two layers. Such a roof covering with roofing felt will be considered reliable (subject to a sufficient roof slope angle).

Euroruberoid

The advantages of this coverage are:

• Long service life (20-30 years);
• Frost resistance (up to -30 degrees);
• The possibility of laying the coating in two layers and no more.

Coating marking

If you cannot determine which roofing material is best for a roof, you should know that this material is marked during production. And in accordance with the type of top coating, as well as the purpose of the bituminous material, the marking will also be read. To understand it when buying, you should know the meaning of each of the symbols. So, they are interpreted as follows:

• Letter "R". Means "ruberoid". As a rule, it comes first in the general abbreviation.
• The letters "K" and "P". They stand next to the first letter and indicate the purpose of the coating. That is, lining or roofing (upper).
• Letters M, K, Ch or PP located after the second letters. They mean "fine-grained", "coarse-grained", "scaly" or "pulverized" spray layer.
• Numerical values 300-400 indicate the density of the cardboard base.

Example: RKK-400. This is a roofing material with an upper coarse-grained layer and a basis density of 400 g/m2.

Choosing a quality coating

In order not to blunder and choose a good one roofing material, you need to buy a coating made in accordance with GOST. In order for the roofing material to serve for a long time on the roof, it is only necessary to lay original material and not fake. Therefore, when buying from a seller, it is advisable to ask for quality certificates, and in marking pay attention to GOST standards. If there are none, it is better to refuse to buy coverage.

An example of marking a quality coating will look like this - RPPP GOST 10923-93.

In addition, it is worth paying attention to such nuances:

• Winding of a covering in a roll. The edges must be even. Permissible deviation along the edge is 1.5 cm. In this case, the bituminous material must be wound tightly, but without sticking together of the layers.
• Appearance. The roofing material should not have chips of the topping, a crack on it, holes or gusts.

Important: according to GOST, no more than two tears can be present along the edge of the material for the entire roll, with a length of each no more than 3 cm.

• The quality of bituminous impregnation. It should be even and have the appearance of a homogeneous layer.
• Cover section. In the section, the roofing material should not have light areas not impregnated with mastic.
• Cover packaging. Each roll of roofing material according to GOST is packed in paper with the marking of the type and type of product.
• Manufacturer's name. It should be next to the label. The date and batch number of the product is also located here.

Important: when working with roofing material, it is worth remembering that this type of coating is combustible. Therefore, when working with such material, you must follow the rules fire safety. In addition, in order to avoid burns with hot mastic, you need to use a protective uniform and gloves. And if all the conditions are met, that well-chosen bituminous roof will serve faithfully for a long time.

Ruberoid is a laminated plastic based on paper (roofing paper) and bituminous resin. Accordingly, it is a soft, flexible sheet (roll) material, strong enough, resistant to ultraviolet radiation, temperature changes, weather-resistant, lightweight and with good waterproofing and dielectric properties. As you can see, there are many advantages listed, so this article will tell you how to properly cover the roof with roofing felt for economical roofing and waterproofing (mainly foundations).

The disadvantage of bitumen became that the cardboard base, although impregnated with low-melting bitumen, can eventually collapse or absorb moisture if protective layer violated. In addition, it is not resistant to puncture and tear; the material is dark, which means it gets very hot from the sun (although it is covered on top with a layer of refractory bituminous resin).

Cardboard at the roofing material different brands has a different density, which determines its purpose. The length of the roll is 15 meters, and the weight and strength are different for everyone. Before covering the roof, the roofing material in rolls must be rewound with the reverse side.

The letters in the abbreviation mean "P" - roofing material; "K" - for the roof of the roof.

The third letter is the type of top powder, for example:

• "K" - coarse-grained
• "P" - scaly
• "M" - fine-grained

The numbers are the density of the cardboard, the larger it is, the stronger the roofing material.

Coarse-grained roofing materials - always for the outer layer. The most powerful waterproofing is provided by built-up roofing material, which has a thick top layer and an additional bottom layer made of special mastic. You can glue it using kerosene or white spirit, or by melting the bottom layer with a burner.

For the middle and lower layers of the roof roof, it is necessary to use roofing materials of the RKP brand, for internal ones with the RKM marking.

How many layers of roofing material need to be laid

For roofing with ordinary roofing felt, at least 2 layers are required

The number of layers of roofing felt depends on how long it is planned to operate the roof, on its slope and on the material used. Where euroroofing material can be laid in one layer, 2 layers of ordinary roofing material are required.

On slopes with a slope of 45 degrees to make a roof that will last for several years, roofing material is laid at least 2 layers: on the bituminous mastic glue the interlayer without crumbs, then the top layer with stone chips.

With a slope of 20-40 degrees and if the roof is needed more durable, for 10-15 years, 3 layers are laid. The two lower ones are lined, the upper one is covered with stone chips.

On roofs with a small slope (up to 15 degrees), 4 canvases are laid, three laying and finishing, they must be laid perpendicular to each other.

On the flat roofs make 5 layers of roofing felt, and everything is glued. Lay perpendicular to each other.

Preparing the roof surface

Important condition: your roof must be dry. In the rain, roofing material should not be covered!

Roofing material is laid on a flat base, rafters or support. All roofing with roofing material is performed only in clear weather. If it rains, you can arrange a canopy and continue work, but only if the surface remains dry or damp from splashes, fog, high humidity air. Otherwise, the material simply will not stick.

If you need to close the roofing material flat concrete roof (for example, from reinforced concrete floors), then a reinforced screed is made on top of the floor, 3-5 cm thick, with a slope (1 cm per running meter) to one side to facilitate snow melting or to gutter. On a dry, cleaned screed with a brush or roller (an option is to pour a ladle of mastic, smear it with a mop), gently apply heated or cold (see recommendations on the bank) bituminous mastic. When it sets, you can glue the first layer of roofing material.

If the slope is small, the crate is needed solid (back-to-back boards or plywood, chipboard), otherwise the snow can push through the canvas and the roofing material will begin to collapse. A slope of more than 30-40 degrees will allow you to make a non-continuous crate, but the gaps are a maximum of 30 mm.

To make a pitched roof, it is necessary to stick a board from the attic between the farms and, attaching it from the outside, nail it to the farm. They begin to make the crate from below, when the crate is slightly larger than the width of the roll, it is smeared with mastic and a lining layer of roofing material is placed on it parallel to the lower edge of the roof. Fastened with slate nails. Then the next layer of the crate is made, and so on.

Laying roofing material on bituminous mastic

Making mastic

Bituminous mastic is sold in stores (now there is no need to melt bituminous resin)

Bituminous mastic- ready to use, sold in jars, does not require melting. It is possible to melt bituminous resin, but this is inconvenient and traumatic. It is easier to dilute the bitumen with gasoline to the consistency of jelly, flavor it with used engine oil (we ask at the service station). The mastic will not crack, it will stick perfectly. The only feature is that it is odorous and flammable until it dries.

The process of laying ruberoid

Ruberoid does not have to be glued. But if the slope is small, and the roof is made in winter, sizing with mastic is required. It is convenient to fasten by pressing with a metal tape (steel or aluminum) or slats, in steps of 50 cm.

The overlap of the sheets depends on the slope of the roof. The greater the slope, the smaller it is (7-20 cm, respectively). The roof must be covered from the bottom up, laying the sheets overlapping and gluing, then the water will not go into the seams. Previously, the panels are cut into pieces of the desired length.

Methods and technology for covering the roof with roofing material

• Cloths across the slope. Laying on the roof from the bottom up, the top row is placed on the bottom row with an overlap of 10-20 cm. Water will not get into the seams.
• Cloths along the slope. The overlap on the side is done taking into account the wind, also 10-20 cm. Laying from the pediment (we look at the wind rose, the wind should not tear off the layers!).
• For the first layer across, and for the upper - along the slope.

Step-by-step instruction:

1. Usually, the first layer of roofing material is placed on the bitumen of the prepared base, with an overlap of 15-20 cm, parallel to the edge of the roof, their ends are wrapped under the edge of the roof, fastened with a rail.
2. Additionally fastened with slate nails (after 50 cm). Coated with bituminous mastic, the next layer is laid, with an overlap through the ridge (its canvases are perpendicular to the first), the edges are also wrapped.
3. Bitumen is applied again and a finishing layer of roofing material is laid.
4. Each next layer is placed with an offset of 1/3 or ½ of the sheet so that the seams of the top layer do not appear above the seams of the bottom: the first panel is folded onto the side of the fence or cut in half, the rest will move as a result.

It is necessary to lay the roofing material with an overlap of 5-15 cm

For roofing onneed a ladder, long enough to nail the batten boards on the highest part of the roof without any problems.

To roll out a roll of roofing material on an almost vertical crate, it is hung on a hook or pipe, like a spool of thread. The hook is hooked to the board of the crate and, moving it, the suspended roll is rolled out.

The last sheet must be fastened from the outside, since it is thrown over the skate. The second layer of roofing material can be laid with throwing over the ridge, across the slope, for this you need a ladder. For pitched roofs made of roofing material, ridge elements are not used.

Laying of built-up roofing material

There is a film on the welded roofing material on the heated side, it turns white and burns out when the heat is sufficient for gluing. It is impossible to overheat the sheets, they easily melt through.

The base preparation is the same.

Step-by-step instructions for laying built-up roofing material

1. A roll of roofing material is placed in front of you so that rolling it forward and gluing it, go along it.
2. They hold a burner in their hands, warming up part of the surface of the roll and the mastic in front of it for 20-30 cm.
3. Then the heated sheet of roofing material with a burnt film (the adhesive base “boils”) is rolled out for about half a turn and glued, trampled down, and all the folds and swellings must be straightened out.
4. It is better if the glued roofing material is rolled with a heavy roller. Then the next section warms up.
5. So gradually, warming up and rolling, and glue the entire roll. It is important to roll, press the glued roofing material.
6. The second sheet is glued with an overlap (by 5 cm) after complete cooling and gluing of the first.

Ruberoid is one of the most common waterproofing materials for roofing houses. It is suitable for flat or pitched roofs, foundations and ground floors multi-storey buildings. It has the form of rolls, about one meter wide and up to 10 m long.

The materials from which the roofing material is made provide reliable coverage and protection of roofs from leakage into the room.

Roofing felt and roofing material are waterproofing materials for roof or foundation. Not all people know what the difference is between them, and they think that this is one and the same remedy, only it is called differently. This opinion is erroneous because it different materials although they perform the same functions.

The difference between roofing felt and roofing felt is that they produced by different technologies and using various materials:

• Ruberoid. The basis for it is roofing cardboard, which is processed with petroleum bitumen (the first layer is fusible, and the second layer is refractory). A coarse-grained substance is applied over the resulting coating with basalt dressing or talc shavings.
• Tol. This type of coating is obtained by impregnating roofing paper with coal tar or shale tar. The upper ball of roofing felts is sprinkled with crumbs of minerals or plain sand.

According to the manufacturing technology, roofing felt is outdated, and roofing material has long begun to force it out of the markets. Ruberoid better and more reliable material. It will last much longer than just. Accordingly, roofing felt is much cheaper for roofing material.

Glassine or roofing felt - which is better?

Modern insulating materials allow high-quality waterproofing of surfaces.

The result of innovative developments is the emergence of high-quality materials - glassine and roofing felt. They belong to surface insulation materials. Sold in roll form. Manufactured from high quality rolled cardboard.

Ruberoid is created by impregnation of cardboard with fusible bitumen. The upper layers are covered with refractory oil bitumen, on which a protective layer is applied on top. It consists of crumbs of asbestos, minerals or talc.

Glassine does not have a top layer, so it less stable to mechanical damage and biological influences. Also, glassine can quickly catch fire, which cannot be said about roofing material. The master must be very careful when laying glassine.

Glassine is not used as a separate insulating material. His used as a substrate under the ruberoid It has excellent thermal conductivity, which allows you to better keep the heat in the room. It is also used as a vapor barrier for roofs and attics.

When the roof of the house has a flat orientation, it is necessary to lay waterproofing material to protect the roof from leaks during rains and melt water.

Also, if the roofs of large industrial facilities begin to leak due to the wear of the old coating, apply new system waterproofing materials. This is exactly what ruberoid is.

Ruberoid - irreplaceable material for waterproofing any structure that has a flat or small pitched roof, the slope of which does not exceed 10 0 .

The versatility of this material allows you to use it on the walls of foundation blocks. It also adheres to foundations as it does to flat surfaces, providing reliable protection home from moisture ingress. This nuance is not unimportant when building houses on wet soils.

Ideal roofing felt for garage roofs. There are types of roofing material that will allow you to cover the garage without a single joint.

Ruberoid is the most reliable material for waterproofing roofs and foundations of houses.

See also helpful video roofing repair video

Popular in construction, in demand, irreplaceable - roofing material. For a long time, this product has been relevant - roofing material is used for the roof as a roofing covering, for waterproofing various designs in construction, as a cushion layer. It is a durable, moisture resistant, inexpensive material.

There are a lot of types of roofing material on the market, which differ technical specifications and cost. It is worth considering it in detail in order to understand which of the varieties of roofing material should be used in individual construction.

You don’t know which roofing material is better for the roof - let’s analyze the features, positive characteristics and cons of the material.

Ideal materials, consisting only of advantages, do not exist. Each has both advantages and disadvantages.

Roofing felt is no exception, during the use the advantages were revealed:

• the price is so affordable that any layman can afford to buy it, while it has good technological characteristics;
• excellent waterproofing properties. When arranging a roof using this material, you can not be afraid that moisture will get under the roof;
• good soundproofing. If we compare ruberoid and metal roof, then the first absorbs noise from rain and hail;
• tear-resistant, yet very flexible. Due to its flexibility, it is very comfortable to work with the material;
• easy to transport, as the weight of the rolls is small;
• a wide variety of species, promotes individual choice.

And all these advantages at an affordable cost. But we can not say about the shortcomings:

• service life of five years. There is, of course, a more durable product - euroroofing material, which can be used for up to 30 years, but its cost is much higher. So from time to time you will have to eliminate leaks;
• for laying, you will have to mount a continuous crate with several rows of lining. This will require additional funds, time and effort.

When laying, bituminous mastic is used to glue the insulator, which can soften at a 50-degree temperature, resulting in depressurization.

These shortcomings are not so significant and with proper arrangement of the roof, they can be avoided.

Varieties of material

What is roofing material - the concept is extensive, and it can be divided into:

• top roofing;
• lining.

Material Composition:

• cardboard saturated with petroleum bitumen;
• refractory bitumen applied on both sides of the material;
• decorative powder applied to protect against sun rays, and from gluing the material in the roll.

This is a classic roofing material, but nowadays they are used innovative technologies in its production, thanks to which the use of fiberglass and polymers became possible. To fully understand the choice of insulator for roof mounting, consider modified materials.

Glass roofing material or hydroisol

In this material, instead of cardboard, fiberglass was taken as the basis, which has the best performance- does not crack, does not rot. From above, to protect against moisture, the glass roofing material is covered with crumbs of mineral origin. Great for heavily sloped roofs. For 20 years does not require repair. It is worth considering the characteristics of this material in more detail.

Advantages

The material is quite new, but has already become popular and in demand. It is called armored and here's why:

• due to the fact that it can withstand a wide temperature range, it does not form bubbles and cracks;
• unlike cardboard, fiberglass does not rot, one hundred helps to increase the life of the material;
• not subject to wind loads, has increased tensile strength, which cannot be said about the classic roofing material;
• service life - 20 years with a single-layer coating, when using a multi-layer installation of a hydroisol, the period increases to 50 years;
• ease of installation under any conditions, unlike roofing material, hydroisol does not crack even when sub-zero temperature, so the laying of the material can be carried out even in winter.

It has a soundproofing property, muffling the sounds from rain and hail.

It is a combustible roofing material, but its characteristics allow it to carry elevated temperatures, for example, at 80 degrees, the material will not melt, will not start to flow.

If we compare that better roofing material or hydroisol, it should be noted that the roof from the second one will be more expensive, but it will last much longer without the need for repairs.

Rubemast

According to the characteristics - this is the same ordinary roofing material, with a cardboard base, smeared with a layer of binder. Thanks to this composition, a good, tight adhesion to the roof is obtained. Installation is carried out using a burner, which melts the material, and it is not necessary to use mastic. The coating will last 15 years

Ruberoid with self-adhesive layer

Its distinguishing feature is the coating with a self-adhesive layer protected by a film. During installation, the film is removed and simply pasted on wooden surface roofs. Under the action of sunlight, the material softens and adheres tightly to the surface. It does not require the use of fire and all sorts of solvents.

Euroruberoid

It appeared on the market not so long ago; materials unusual for an ordinary product are used in its production. Textile base impregnated with bitumen with synthetic rubber, which significantly improves technological characteristics material. The next layer is polymer films, which are covered with a protective dressing that performs a decorative function, as it has different colors. Euroruberoid can serve up to 30 years without leaks and damage.

Causes of leaks on a roof covered with roofing felt

The material is waterproof, resistant to the formation of fungus and mold, does not decay in the sun, all this indicates the reliability of such a coating. Roof decking is made using open fire- direction method.

A roof leak with such a coating can occur for many reasons:

• Inappropriate use. All manufacturers say that this material cannot be used as a covering material on exploited roofs, since the roofing material can be damaged under constant mechanical action. These recommendations are sometimes ignored, which leads to damage that will have to be patched.
• Impact of precipitation. During rain, a small amount of water penetrates the top layer of the material, and when cold weather sets in, it freezes, which can lead to the appearance of microcracks.
• wind load. In some regions, winds often blow with strong gusts, the material may not withstand - damage appears on it.
• Illiterate installation. Roof leakage can occur from non-compliance with the material flooring technology. For example, improperly executed overlaps, unprepared roofing.
• Poor quality material. This is a very common cause of material damage and leaks. Buying cheap material, you should be prepared for the fact that you will often have to repair the roof from roofing material.

Repair work

Any roofing material fails over time, and begins to require repair - roofing material is no exception, since roofing material for roofing, mounted in 6, only 15 years, serves. First, microcracks appear, which are washed with water, which leads to leaks.

Such defects can be eliminated independently:

• Payment repair. This type of repair is carried out if the damage to the coating is minor and rare. Patches are applied to the roofing material small area. This method has one tricky nuance - on top layer coating contains stone chips, which reduce adhesion when gluing a patch. Such repairs can repair the roof for 2 seasons.
• Roof repair with roofing material on the old coating. At in large numbers cracks, it is possible to fuse or glue several new layers of roofing material. Before starting the installation, the old coating is cleaned, removing the crumbs, treated with bitumen or mastic. This repair option is possible if there are no swellings and moisture between the layers on the roofing material.
• Repair with the dismantling of the old roofing material. If a roof that has not been repaired for more than 15 years is leaking, the old coating will have to be removed to the ground. Then a new multilayer coating of roofing material is mounted.

When conducting repair work, do not forget that roofing material is a combustible material, and installation must be carried out in compliance with safety regulations.

In custody

So, we found out that roofing material is a building material with a low cost, and good performance. On the market you can buy classic look, an analogue of roofing material, which is more wear resistant and has a longer service life, but is more expensive. The appearance on the market of analogues produced according to the latest technologies, allows you to choose products with a long service life.

If earlier this type of roofing was used to cover the roofs of sheds and outbuildings, then on this moment there is roofing material and its analogues, which are not inferior in strength to slate and soft tiles.

Starting the construction of a new roofing, you can choose any roofing material. However, when it comes to reconstruction old roof you have to work with what you have. Professional roofers note that a significant part of little-used, utility and seasonal buildings in Russia over the past 50 years has been covered with roofing material, which has short term operation. During operation, cracks, bubbles and holes appear on this roofing material, then the homeowner understands that the roof needs to be re-roofed. To save time and money, many craftsmen recommend leaving the old roofing material under the corrugated board as a lining. In this article, we will tell you if this is possible.

Ruberoid is a roofing roll material, which is made from cardboard with a density of 200-420 g/m2, depending on the type of material. Cardboard is impregnated with low-melting oil bitumen, and then sprinkled with armoring powder in the form of stone or granite chips, talc, chalk or quartz sand.In accordance with the density and type of dressing, roofing material is divided into two types: lining and roofing. According to reviews experienced craftsmen 3 “chronic diseases” can be distinguished from the roofing roof:

1. Low mechanical strength. Due to the low mechanical strength of the roofing material during operation, it is often damaged by strong gusts of wind, hail, falling branches.
2. Crack formation. Penetrating under the armoring powder, atmospheric moisture, when the temperature drops below 0 degrees, provokes the formation of cracks.
3. Bloating. Under the influence of ultraviolet rays and atmospheric moisture, blisters and bubbles often form on the surface of the roofing material, reducing the waterproofing properties of the coating.
4. accumulation of condensate. The roofing material does not allow steam to pass through, therefore moisture condenses abundantly on the rafters, which leads to decay of the wood.

Important! The service life of roofing felt as part of a multi-layer roof is 7-10 years, after which the roof requires replacement or reconstruction. In such cases, some masters recommend laying corrugated board without dismantling the old coating. They claim that damaged roofing material can be used as a waterproofing layer. roofing cake.

Profiled sheet flooring on roofing material

According to professional builders, the dismantling of the old coating often takes most time and accounts for more than a third of the cost of roof reconstruction. The roofing material begins to melt at a temperature of 60 degrees, so for several years of operation it sticks to wooden rafters and a crate that it is almost impossible to remove it. Therefore, many masters recommend laying corrugated board without dismantling the damaged coating. However, this technology can not be used in all situations:

• If the structure to be covered is of an economic or industrial type, is used seasonally or is not heated, the corrugated board can be laid directly on the old roofing material, because in such a room there is no difference between the external and internal temperatures, leading to the formation of condensate.
• If the building to be covered is used permanently as a residential building, it is heated, professional craftsmen it is not recommended to lay a profiled sheet on roofing material, since it does not allow steam to pass through, which is abundantly formed in such structures. The steam condenses on the underside of this material, causing the roof truss to rot.

Note! If the old roofing material is preserved during the installation of a new corrugated boarding, counter-lattices and a new crate made of timber impregnated with an antiseptic composition are nailed onto it to create a ventilation gap that prevents condensation.

Differences between the roofing cake of a "hot" and "cold" roof

Roofing felt waterproofing layer

From the point of view of building codes, roofing material is not optimal material for lining waterproofing, although it can still be used. It is laid on the rafters, fixed with roofing nails, and the joints between the strips are soldered to obtain an airtight coating. Such practically monolithic layer does not allow moisture and steam to pass through, which leads to condensation in rafter system roofs. When installing corrugated board on roofing felt, the following factors must be considered:

1. profiled steel sheets have high thermal conductivity, and therefore get very hot in the sun. The melting temperature of the roofing material is only 60 degrees, so the corrugated board, laid without a counter-lattice and crate, can melt a hole in it.
2. Due to the difference between the internal and external temperatures, steam condenses on the inner surface of the roofing material, penetrating inside wooden elements truss frame and leading to decay.
3. When bituminous material used as underlayment waterproofing in the thickness is heated, bituminous fumes are formed, which are considered harmful to human health.

Professional roofers believe that when reconstructing an old roof, you can leave the roofing material for waterproofing, after removing the bubbles and moisture that has accumulated inside the coating. However, when creating new roof, it is better to use special diffuse membranes that allow steam to pass through.

Video instruction