Insulation of soft roof pie. Roofing pie for a soft roof: general design rules and possible options. Pie for a cold roof

Any roof is a structure made up of more or less layers, and the entire set of these layers is called. Layers perform their functions, and for all types of roofs there are standard sets of materials, and sometimes several sets to choose from. So, the roofing pie for metal tiles is no exception; it, like other pies from various roofing materials, do according to certain rules.

The structure of the roofing pie.

All installed parts play a role in the correct installation of the roof. Therefore, the roofing pie is installed in strict accordance with the technological maps.

Cold roof roof

One of the simplest options for installing a metal tile pie is to install the pie on a cold roof. It includes, not counting the supporting structures, only the material itself and the waterproofing film mounted under it. The film is first secured with small nails or a construction stapler. Finally, it is pressed with self-tapping screws for the counter-lattice (25x100), running along the rafters. In this case, the waterproofing film must be attached with some sagging (from 10 to 25 mm) to ensure ventilation and drainage of condensate into the drainage tray. Otherwise, when the film fits tightly, moisture will accumulate, which will lead to rapid corrosion of the coating. The same sheathing board is placed on top of the counter-lattice for further installation. However, in their homes, cold metal roofing is done quite rarely due to the characteristic feature of the material - it is very loud, so noise during rain can cause inconvenience. The noise level can be reduced by installing a thermal insulation coating.

Warm roof roof

In order to reduce noise, as well as to reduce the empty space under the roof, a warm roof is installed. Roofing pie for metal tiles under a warm roof includes:

Scheme of a roofing pie for a warm roof.

1. A vapor barrier that allows steam to escape from the house, but does not allow it to escape from the street.
2. Rafters and longitudinal purlins are the main structure of the roof.
3. Thermal insulation installed between rafters and purlins. It is necessary to leave room for ventilation.
4. The waterproofing must sag from the coating level by 50-40 mm, while leaving the same distance above the surface of the insulation. The waterproofing device can be made in the form of an impermeable film or in the form of a membrane that allows steam to pass through from the inside and does not allow moisture to pass through from the outside of the roof. In the second case, the membrane is installed with a smaller distance to the insulation.
5. The counter grille is installed parallel to the rafters and presses the waterproofing. Serves as a fastener for roof sheathing.
6. Sheathing is a beam with a design cross-section (50x50), which is attached in increments of 35-45 cm along the slope and on which the roof is made for metal tiles.
7. Metal tile sheets.

additional information

Installation plan: fastening the vapor barrier film, filling insulation, film, sheathing.

Roofers pay Special attention the correct location of the waterproofing coating and ventilation gap for some reasons. One of the weak points of the system is the insulation layer. Foam insulation devices for roofing are rarely used. Its only advantage is that it does not transmit or absorb moisture, while a device of rolled thermal insulation in the form of glass or mineral wool can absorb it. With a non-standard rafter pitch, foam insulation has a large amount of waste material, which, combined with a higher cost, makes this option economically unprofitable. When absorbing moisture, thermal insulation wool loses 80% of its thermal insulation properties. Therefore, moisture should not be allowed to reach the insulation.

And if it does get there, then the only way to remove it is to blow it out naturally. For this reason, a gap of 30 to 40 mm is always left between the upper layers of the roof and the thermal insulation. The gaps are arranged in such a way that the air flow passes from the overhang of the covering to the ridge, where special gaps are also installed. In addition, a gap (10-15 mm) is left between the metal tiles and the waterproofing.

Characteristics of metal roofing:

1. The thickness of the metal base (0.4-0.5 mm) affects the strength of the metal tile, but at the same time the weight of the entire roof.
2. Protective layer materials may have different resistance to aggressive influences, which is reflected in the cost of metal tiles.
3. Sheet length. The longer length simplifies the installation of roofing material and reduces the risk of leakage, but increases the possibility of longitudinal deformations.
4. Wave height. Greater height strengthens the metal tiles, but gives less usable width, since galvanized sheets of the same length are used for all types of tiles.

The procedure for installing a metal tile pie

The roofing installation process takes place in the following order:

After installing the components of the metal roofing pie, the final stage of roofing with the tiles itself is carried out. The roofing is carried out using special self-tapping screws along the sheathing, in accordance with the technological maps issued when purchasing metal tiles

1. A vapor barrier film is attached to the inside of the rafters using a construction stapler or counter-lattice. Various types of vapor barriers require a gap with insulation. In this case, a counter lath with a thickness of 30 mm or more is placed along the joists and the vapor barrier is attached to it. Taking this into account, the roll runs along the slope, fastening is carried out from the bottom row to the top. Each subsequent canvas is laid with an overlap of 100-150 mm over the previous one, the same applies to longitudinal joints.
2. Insulation is stuffed into the space between the joists from the outside, taking into account the air gaps of the roof.
3. Next, waterproofing is installed along the slope from bottom to top and with overlaps. As in the case of vapor barriers, fastening is carried out with a stapler or small nails. Do not forget about sagging, as this is then quite difficult to correct without completely dismantling the overlying roofing material.
4. When installing the film, it is fastened along the joist with a vertical counter-lattice (beam measuring 30x50x50) with a nail pitch of about 300 mm (most often there is a special marking line on roof waterproofing)
5. A lathing made of edged boards thickness 24-32mm (depending on

Every year, manufacturers of bituminous materials produce more and more new coatings, but at the same time the roofing pie is under soft roof remains unchanged. The exception is its minor changes based on the finishing layer used. Today, soft roofs have high waterproofing and elasticity parameters, therefore, working with them is not difficult. In this article I will describe what the pie should consist of so that the roof does not require expensive repairs in the first year of operation.

Indicators of soft roofing

The construction of a roof made of soft products is carried out in several layers. Not only the effectiveness of the protective layer, but also the service life of the entire building depends on their location. For example, without installing a vapor barrier layer, the thermal insulation slabs will quickly become saturated with moisture, and you will have to replace them, and without eliminating the cause, this will happen again.

Today, bituminous shingles almost entirely occupy the niche of soft roofs. In fact, this type of roofing is recognized precisely by this product. The raw material for the production of soft tiles is most often fiberglass impregnated with a special bitumen compound or rubber. The protective layer, as a rule, is a mineral coating.

In addition to tiles, a material called shingles is common in private construction. Its advantages are as follows:

• Increased resistance to aggressive external environments. Bituminous materials have the highest possible moisture resistance and can withstand temperatures from -50 to +100 degrees. They never become covered with moss and do not rot, therefore, they are not attractive to other small rodents
• The operating period is about 25 years, which is quite impressive considering the cost of this material. This indicator may be higher if during the installation work the processes proceeded with maximum quality
• The soft surface is good sound insulation. Its noise-absorbing properties are the highest priority for some developers along with all the positive aspects
• Simplicity of installation work. As mentioned above, bitumen products are highly elastic. This allows you to easily lay the material even on complex rafter systems. Thanks to the properties of the coating, installation work can be carried out independently. To do this you will need a good gas burner and special clothing for working at heights

The use of soft roofs is only advisable if the slope of your roof is in the range of 15-45 degrees. Laying roofing carpet individual elements on flatter surfaces it is fraught with leaks. The fact is that the fastening method does not make the surface completely sealed. If your region has high temperatures during the hot season, then it is better to make the slope as small as possible, this is due to the fact that with strong heating, the bitumen product can drain from a steep slope.

The introduction of new technologies into production allowed manufacturers to create a new type of soft tiles. It is practically no different from its analogues, but has a self-adhesive base. Thanks to this, installation work can be carried out in a very short period and you do not need to use many tools.

To get acquainted with the product, I advise you to study its structure, which includes the following layers:

• There is a protective film on the bottom of the bitumen product. It performs the protective functions of a self-adhesive layer
• The composition of the adhesive allows for high-quality gluing of the bitumen material, both to the sheathing and to another identical element. The end result is an ideal waterproofing surface.
• After these layers comes rubber bitumen. It is thanks to it that soft materials have high elasticity and strength properties.
• In the center there is a reinforcing base or fiberglass in other words. This material is the basis of the tiles and does not allow them to tear.
• Lay another layer of rubber on top of this layer, and cover it all with mineral powder. Bulk protection gives the entire material resistance to mechanical damage and direct exposure to sunlight, making the product fireproof

Roof pie under soft tiles

The soft roof pie has a somewhat complex structure and for its high-quality arrangement it is necessary to understand the functional tasks of the individual layers. All work must begin with preparatory work. At this stage, the base is carefully examined and in case of any serious deviations from the norms, cosmetic repairs are carried out.

A soft roof pie with insulation has the following structure:

1. Vapor barrier layer. It is laid from below in order to prevent moisture coming from below. There is a simple answer to the question of where it comes from. During human life, a certain amount of moisture is released. The most basic example is cooking and writing. The warmed air rises and condenses on the cooler side, so it enters the attic space and can then penetrate the roof pie in the same way. It is worth noting that the presence of even a small amount of moisture in insulation boards reduces its performance by more than half
2. Thermal insulation layer. Any material can be used on pitched roofs, but on flat roofs it is better to pay attention to hard types, for example, mineral wool slabs
3. Waterproofing layer. In fact, it is no different from vapor barrier and is often made from the same material, but the quality suffers. The main task is to protect the thermal insulation layer from moisture coming in the form of precipitation and condensation
4. Lathing. This lumber system allows the load from the overlying layers to be distributed as evenly as possible. As a rule, soft roofs are laid on a continuous sheathing made of OSB boards, moisture-resistant plywood or cut boards
5. The lining layer creates a soft base and does not allow the sensitive layer of bitumen shingles to receive mechanical damage. It has a dense structure and serves as additional waterproofing and protection from strong gusts of wind.
6. The finishing layer is the roofing itself. It gives the structure a finished look and serves as protection from the aggressive external environment.

Manufacturers of roofing materials often provide recommendations for the installation of their products. If you want to achieve maximum performance, listen. An incorrect combination of products will inevitably lead to problems that will appear in the first year of operation, for example, leaks and the beginning of rotting of wooden elements.

Requirements for lathing

Metal roofs have a more rigid surface, therefore, the entire structure will also be highly durable. As for soft roofs, they have problems with this. To ensure good strength properties, a number of special measures must be taken.

A little higher in the article we already talked about the sheathing, or more precisely what materials it should consist of. Now, you need to find out how to build it. This process takes place in just three steps.

1. After laying the vapor barrier layer, a counter-lattice must be laid on the rafter legs. Its placement must be strictly parallel to the rafters. As a rule, these elements are made from timber coniferous. Its thickness should be 3-4 centimeters. Long nails are used as fasteners
2. The counter-lattice is covered with auxiliary boards. They must have a cross-section of at least 150x20 millimeters and be attached perpendicular to the rafters
3. The sheathing itself is placed on top of all this. If you have easy access to lumber, you can build it from boards, but it is best to use OSB boards or moisture-resistant plywood. The dimensions of the boards must be selected in such a way that the plane is as flat as possible, otherwise the material laid on top may be greatly deformed, which will lead to leaks

IMPORTANT: When laying OSB boards or moisture-resistant plywood, do not forget about ventilation gaps. A distance of 3-5 millimeters is enough to ventilate the air.

Remember that laying underlay carpet is mandatory. If you skip this layer, the rough surface of the lumber will easily damage your soft covering.

Requirements for waterproofing

A roofing pie for a soft roof must necessarily include high-quality waterproofing. As a rule, it is a rolled material and is laid in strips. It is worth noting that during installation work it should not be stretched; it should be slightly sagging. For good protection, the overlap of the material should be about 15 centimeters.

Today in construction you can find only two materials that can be used in this regard.

1. Waterproofing film. The simplest and cheapest insulating material. Polyethylene is used as a raw material, therefore, strength characteristics material is very low, and after prolonged exposure to ultraviolet radiation it becomes even more fragile
2. Membranes. This product is a kind of film analogue. The fact is that more advanced polymers are used in its production. The structure of the membranes is significantly different from the cheap analogue. The fact is that its structure has pores similar to funnels. It is thanks to them that the material can pass moisture in only one direction. This is a really good material if you care about the insulating layer. Moisture that gets into the roofing pie can leave it in some way and will not come back. There are also varieties that do not allow condensation to accumulate on the surface of the membranes

If we take into account the experience of some developers, then when installing soft roofs, we can recommend using vapor-permeable products. Please note that they only allow steam to pass through, not water. Their use will eliminate the possibility of condensation appearing in the roofing pie from the air. The fact is that bituminous materials, when heated strongly, contribute to the appearance of moisture from the air, which has a detrimental effect on all components of the roof.

Requirements for roofing pie

The roof pie for soft tiles may differ slightly from the standard set of layers. Some of them are removed from the composition due to their inappropriateness. The following factors may influence this:

• Functional purpose of the building. It can be industrial, residential or commercial
• Frequency of use. In buildings that are used only in warm seasons, it is not advisable to install heating systems; therefore, thermal insulation boards can be removed
• If there is a residential attic in the house, it is imperative to use thermal insulation
• Weather conditions in your region

Producing the device bitumen roofs, you should use your head as much as possible and take into account the compatibility of the products included in the pie. Never ignore the manufacturers' advice; they often play an important role in installation.

If you have doubts about the materials, ask the seller or friends about them, and in extreme cases, you can turn to specialists.

The construction of a roof under a soft roof is an expensive part of the construction of the entire building, but it is better not to skimp on these layers. If you lay the surface with low-quality materials, then soon you will need repairs, for which you will spend a much larger amount.

Soft (bitumen) shingles are a relatively new construction material. Its basis is fiberglass, impregnated with bitumen on both sides.

This design provides the material with fire resistance, moisture resistance and elasticity, allowing the tiles to be mounted on pies with bends and complex parts.

During production, mineral chips of different shapes and colors are applied to the surface of the tiles, which creates a wide range of design solutions.

It is especially appropriate to use the material when arranging roofs with large angles slope of the slopes.

This name refers to a structure that fills the space of the roof between its outer and inner edges, that is space inside the rafter frame. It consists of layers various materials, each of which performs its own function. Because of its layering, the structure has a name similar to the name of the culinary product.

Roofing pie under improves waterproofing properties roof, ensures its insulation. Separate layers are responsible for each of these functions; for example, to increase moisture resistance, a waterproofing layer is included in the cake. The number of components of the pie depends on the type of roof: insulated roofs require more layers.

Now let’s look at the roofing scheme for soft tiles in more detail.

Pie for a cold roof

There is no need to insulate the roof in cases where the owners of the house do not intend to use the attic space as a living space. Pie cold roof has a relatively simple structure and consists of six layers:

Soft tiles, unlike metal profiles, requires additional pads, fixing and strengthening the position of the coating.

Waterproofing is needed to prevent the formation of condensation in the internal space of the roof. It can be placed not only under the sheathing, but also in front of it.

Mansard roof installation

If you intend to use the attic space for permanent or temporary residence (that is, transform it into an attic space), then thermal insulation of the roof becomes a necessary action. The insulation layer increases the thickness of the roofing pie and complicates its installation. Insulation also involves carrying out a vapor barrier to avoid the negative impact of the internal condensation of the room on its materials.

Thus, the roofing pie for soft tiles includes two additional layers. The completed design looks like this:

• Tile covering.
• Underlay carpet.
• OSB coating.
• Lathing.
• Waterproofing.
• Rafters.

soft roof pie with insulation

Bitumen itself has good moisture-proof properties, therefore laying a separate waterproofing layer is not necessary here, as opposed to installing a metal tile roof. But with a high slope angle and the presence of insulation, additional waterproofing will significantly increase the operational potential of the roof.

When laying the cake, it is important to leave small gaps between the layers to allow natural ventilation.

Waterproofing and vapor barrier

If roof slope angle is less than 18 degrees, the waterproofing layer is laid only on the most vulnerable places: ridge, overhangs, valleys, areas around pipes.

If more than 18 degrees, then the waterproofing is laid over the entire roof area.

Moisture-proof materials are divided into liquid and solid. The first ones are applied to flat roofs or those with a small angle of inclination (up to 5%). If the roof has a greater slope, then materials are used in solid forms, such as film and roll.

Since soft tiles are mainly used for sloping roofs, then we will talk specifically about hard waterproofing.

The highest quality moisture-resistant materials are waterproofing membrane. Its pores do not have a standard cylindrical shape, but a funnel-shaped one with a narrowing on the upper edge. This form allows condensation to escape freely from the interior of the roof, but does not allow moisture to enter.

1. If special Constructive decisions, That waterproofing is laid between the rafters and the sheathing. It is fixed to the rafters using a construction stapler, and it should be fastened to the sheathing with self-tapping screws.
2. Soft roof waterproofing is laid in the direction from eaves to ridge. The overlap between two sheets of material should not be more than 12 cm
3. The sheets are fastened to each other using adhesive tape.
4. The film or roll may sag in the space between the edges of the rafters, but no more than 20 mm. Such sagging will improve the ventilation capabilities of the roof.

Vapor barrier also protects the insides of the roofing pie from moisture, but, unlike waterproofing, it prevents moisture from entering the interior of the house, and not from the environment. Its main function is to protect the insulation, so vapor barriers are rarely installed in cold roofs.

NOTE!

When choosing a vapor barrier material, you should pay attention special attention to its strength, since during operation of the roof it will be subject to insulation pressure.

The most popular materials for vapor barrier films are polyethylene and aluminum foil.

waterproofing the roof pie under a soft roof

The film is attached to the rafters using galvanized nails or staples. It is important to carefully connect all the joints, otherwise condensation will penetrate into the inside of the cake. As with the installation of waterproofing, it is necessary to leave a slight sagging of the film to improve internal ventilation. But if a vapor barrier is installed instead of a film, then sagging is unacceptable, the material must be tensioned.

Before installing all insulating layers, the rafters are treated with antiseptic impregnation.

Insulation of flexible tiles

Despite providing protection from moisture with vapor and waterproofing, the material for the insulation must also be sufficiently resistant to water so that it is not damaged by the slightest leakage of the protective layers.

Also important are criteria such as:

The most popular materials for insulation are mineral wool, glass wool, polystyrene foam, penoizol, polyurethane foam. These materials are distinguished by their low cost and resistance to negative influences. But it is important to ensure that they are well insulated from the living space, since small particles of some types of insulation (for example, glass wool) are harmful to humans with its constant entry into his body.

CAREFULLY!

Before installing the insulation, provision should be made for creating gaps with both the waterproofing and the vapor barrier. This is necessary to ensure ventilation and prevent damage to materials when rubbing against each other.

Insulation of a soft roof is carried out in the following order:

1. Nails are driven into the lower edges of the rafters at all corners at equal distances from each other.
2. The thermal insulation material is slightly compressed and inserted into the space between the rafters.
3. The cords are threaded between the driven nails and secured in a crosswise position; they are the ones who make the insulation securely fastened.

Instead of cords, you can use slatted wooden sheathing; it is attached not by diagonally crossing, but parallel to each other in increments of 40 centimeters.

Insulation of tiles is carried out by analogy with other coatings

Thermal insulation is usually installed in two layers. The insulation blocks should not protrude beyond the lower and upper planes of the rafters; otherwise, the materials must be trimmed.

These are the main components of the soft tile roofing cake. Its main difference is that the material of such a roof has good waterproofing, and the installation of a separate moisture-proof layer is not necessary, but all other necessary elements are similar to those of other types of tiles.

Useful video

What does a roofing pie look like under flexible tiles in video format:

In contact with

To an uninitiated person in the intricacies of construction, the roof appears in the form of an accessible coating that protects his household from weather adversity. In fact, this is a complex structure, each element of which must flawlessly perform the work assigned to it. The components are laid in layers like a culinary product that shares its name with the roofing system.

Layers are laid in a certain order, violation of which threatens a noticeable decrease in consumer characteristics. The service life of the roof and the heating technology of the house as a whole depend on how correctly the roofing pie is constructed for a soft roof.

Roofing pie - generalized technical term, combining a number of designs with a similar “layered” structure. The combination of layers should protect the home owners from atmospheric attacks and protect the internal filling of the pie from premature deterioration.

The standard structure of a roofing pie includes the following required components:

• Vapor barrier. Prevents the penetration of vapors from the interior of the house and the condensation of moisture on the building materials used in the construction of the roof;
• Thermal insulation. Helps retain heat, protects against noise, winds, and cold temperatures coming from outside;
• Waterproofing. Prevents the penetration of rainwater and melted winter precipitation into both the roof structure and the building;
• Decorative coating, which simultaneously performs the work of wind protection.

Includes materials with excellent waterproofing qualities. These include bitumen roll representatives, piece analogues, mastics and a new generation of membranes. A couple of decades ago they served only as a barrier against water, but now they also successfully play the role of decorative coatings. This is due to the improved external surface and the development of installation methods that allow super-thin materials to be attached to any type of base.

The combination of insulating and decorative properties has made it possible to reduce the number of main layers in a roofing pie to 3, if one of the types of rolled materials is used for arranging the roof.

When waterproofing is not completely abandoned. However, it is laid as an additional waterproof layer and covers the roof either completely, if the slope of the slopes does not exceed 18º, or partially in strips along the overhangs, along the ridge and valleys, around pipes and at junctions on roofs with slopes steeper than 18º.

The above list of main roofing layers has the nature of general recommendations. In fact, it is modified by reducing or adding functional elements, because the scheme for forming an ideal roofing structure is influenced by a number of significant circumstances, such as:

• type and purpose of the object being developed, i.e. is it a residential building or a domestic structure;
• temporary or permanent use, determining the use or rejection of thermal insulation;
• the shape of the roof and the steepness of its slopes, directly related to the choice of materials for the roofing;
• type of base for installing a pie and laying a soft roof;
• the presence of an exploited or unexploited attic;
• regional climatic features, according to which the thickness of thermal insulation is determined;
• compatibility of construction layers, because in case of incompatibility, separation or migration layers will be required.

A well-designed soft roof pie is constructed taking into account the entire range of the listed conditions. Without information about the specifics of the project, no one will give exact recommendations, but it is worth familiarizing yourself with the principle of construction, regardless of whether you will build the cake yourself or hired roofers will do its installation.

Principles of constructing a roofing pie

Let's look at the most common pie designs for soft roofing used in private construction. Flat and low-slope roof structures are rarely built over low-rise buildings. However, there are adherents of the strict cubic forms of the techno or high-tech style, and their numbers are steadily growing. Most often, flat roofs are erected over bay windows, attached terraces, utility compartments of the building, garages, etc. They are covered with bitumen-polymer materials or a membrane, laid on reinforced concrete floors or a base made of galvanized profiled sheet.

The most popular in private construction is bituminous shingles, used in the construction of pitched roofs with a slope of 12º or more. It is mainly used for coating rafter system, erected both over dachas and over country houses. Let's start with it.

Roofing pie for flexible tiles

Soft tiles are used to cover buildings with cold attics and houses with insulated attics, the designs of which, of course, have radical differences. In the first case, there is no need to use insulation, in the second, thermal insulation is a mandatory component. Both options require a continuous sheathing made of antiseptic-treated boards, sheets of moisture-resistant plywood or OSB-3 oriented strand boards.

The simplest non-insulated option

The scheme for laying a soft roof over an uninsulated attic is extremely simple:

• a counter beam installed across the rafters is nailed to the rafter legs. The recommended size of the beam is 50x50; it is attached with two rough nails to each rafter beam. The installation pitch of the counter beam depends on the pitch between the rafters. If the standard distance is 0.7-0.9 m, the block is nailed after 30 cm;
• slabs of continuous sheathing are laid on the counterbeam in a staggered manner so that there are no cross-shaped connections between them. The edges of the slabs should rest on the counter-lattice elements. Fasten the slabs every 15 cm with rough nails to the block;
• A self-adhesive waterproofing carpet is laid, the installation of which is carried out depending on the steepness of the slopes. When the slope is 18º or more, only the slopes, ridge, valleys, junction areas and pipe passages through the roof are covered with waterproofing. Less steep roofs are completely covered with an insulating carpet;
• Soft tiles are installed on top of the waterproofing barrier.

If a continuous sheathing is constructed from boards, then the need for a counter-lattice is automatically eliminated. The boards are fastened directly to the rafter legs and laid with a gap of 3 mm between the elements.

Installation of an insulated roof

The pie for an insulated roof is much more complicated. Its design is complemented by thermal insulation. And if it exists, then you will need a vapor barrier material that protects the insulation from moisture accumulation. The result of moistening is a decrease in insulating characteristics and the accompanying processes of rotting with subsequent destruction. Ventilation is also needed to remove condensation from under roofing, unable to pass drops dangerous to wood on its own.

The layout of layers of roofing pie for an insulated pitched roof, which involves the use of an attic, is as follows:

• On the inside of the rafter system, a vapor barrier membrane is attached directly to the rafters with a stapler. It is laid parallel to the overhangs in strips from bottom to top. The strips are connected into a single web with double-sided tape;
• Once the vapor barrier has been installed, a counter-lattice is constructed from the bar, again from the inside, the installation step of which depends on the material of the planned internal lining of the attic. For example, under plasterboard sheathing, it is advisable to place the sheathing bars at a distance of 40 or 60 cm;
• On the outside of the roof, auxiliary struts are mounted between the rafter beams. They are required to hold the insulation boards. The spacers are placed in increments of 2-3cm smaller than the height of the insulating board. So it is necessary that the thermal insulation is firmly fixed in the compartments created for it, “straightening out” after slight compression during the installation process;
• The resulting semblance of a honeycomb is filled with heat-insulating material, the thickness of which should be 3-5 cm less than the thickness rafter legs. This necessary condition for proper ventilation of the roofing pie;
• the counter-lattice is constructed again. It is nailed to the rafters along their direction to form ventilation ducts - roof vents;
• a continuous sheathing is attached to the outer counter-lattice, on top of which an additional waterproofing carpet is laid;
• soft tiles are laid.

For installing a warm roof with soft tiles in northern regions sometimes the thickness of mineral wool insulation of 15 cm is not enough - a generally accepted standard for the middle zone. Then, on the outside, first a tier of counter beams is installed transverse to the rafters for laying the second layer of insulation, then a beam is installed along the rafters for installation of a continuous counter batten.

If you plan to lay bituminous shingles on top of low slopes constructed from reinforced concrete slabs or arranged by raking and pouring a cement-sand screed on top, the vapor barrier is laid on a concrete or cement-sand surface. A board is installed on top of the vapor barrier on the edge in increments of up to 90 cm, and then required amount tiers of counter-lattice.

Roofing pie with wooden elements cannot be closely adjacent to chimney pipes. The required distance from the pipe walls can be found in SNiP 41-01-2003. The empty space is filled with non-flammable mineral wool material, and an apron made of galvanized or laminated metal is installed outside around the pipes.

The video will present the stages and principles of constructing a roofing pie under soft tiles:

Roofing pie for rolled materials

For the construction of roofs with a slight angle of slope, with a spread from 1º to 12º, bitumen-polymer materials or roofing membranes are used. It just doesn't make much sense to install custom shingles on them. And the patterned aesthetics of flexible tiles on flat and almost flat roofs will delight only birds.

There are no significant differences in the set of layers for piece and roll material. The sequence is similar: vapor barrier → insulation → hydrobarrier - also a decorative coating and wind protection. However, the installation of a roofing pie has its own specifics. Continuous sheathing and counter beams are not used. The layers are laid without auxiliary wooden elements on concrete floors, cement-sand screeds, corrugated sheets, prefabricated leveling structures. Therefore, we do not focus on consistency installation actions, but on the styling features.

Principles of vapor barrier design

The following materials serve as a vapor barrier layer for laying roll materials:

• bitumen and bitumen-polymer vapor barrier, fused onto a concrete or cement-sand base, including cement-sand insulation with vermiculite, expanded clay, perlite in the form of filler in case of a slope slope of more than 6º. If the slope is less, bitumen vapor barrier can be laid without gluing or fusing to the base.;
• polyethylene reinforced or non-reinforced vapor barrier, laid loosely along the corrugations of the profiled sheet or glued to it if the slopes are inclined more than 6º.

In the construction of a soft roof using prefabricated screeds made of plywood or OSB boards, any type of vapor barrier material can be used, but the recommended option is a bitumen-polymer vapor barrier with a polyester fabric base. However, it is also not forbidden to place polyethylene on a concrete surface, but before this you should create a separating layer of glassine.

The vapor barrier layer is laid in the form of a kind of pallet extending onto the vertical planes of adjacent walls and parapets. The height of the sides of the pallet is calculated as follows: the thickness of the thermal insulation layer plus 3-5 cm. Similar sides are installed around the intersection of the roof with chimney pipes and other communications.

Both vapor barrier options must be combined into a continuous sheet. Strips of bitumen and bitumen-polymer material are laid with an overlap of 8-10 cm on the sides and 15 cm at the end joints and welded with a gas torch. The connection of polyethylene strips is made using adhesive tape.

Rules for laying thermal insulation

You can insulate a soft roof with a roll covering using literally any material, but mineral wool boards and foam polystyrene are considered priority. On concrete bases and cement-sand screeds, the insulation system is laid in one tier, on corrugated sheeting in two so that the joints of the elements of the upper row are not located above the joints of the lower layer.

The hardness of mineral wool for single-layer insulation is 40 kPa with a compressibility of 10%. To construct two-tier thermal insulation, it is not necessary to use slabs with equal rigidity. The bottom row can be folded with material with a strength rating of 30 kPa, the top row 60 kPa.

If a polymer membrane is used as a waterproofing and decorative roofing covering, a separating layer of fiberglass or geotextile must be laid between it and the polystyrene thermal insulation. Otherwise, the membrane will lose its consumer qualities before the time guaranteed by the manufacturer due to the gradual migration of plasticizers into the adjacent material. A separating layer is also required when installing an inverted ballast roof, if the polymer coating is laid on bitumen vapor barrier layer.

Laying mineral wool slabs on corrugated sheets without first constructing a prefabricated screed from plywood or OSB sheets can be done if the thickness of the thermal insulation is twice as large as the distance between adjacent corrugations. If reality does not meet this condition, a prefabricated screed is constructed before laying the insulation.

The installation of thermal insulation under a roll covering requires compliance with the following rules:

• the thermal insulation material is attached separately from the covering laid on top;
• with the mechanical fastening method, each thermal insulation slab and its individual part is fixed at two points. The insulation is fastened to the corrugated sheet using steel self-tapping screws with a plastic sleeve in the shape of a fungus. Plastic bushings are not used if the slope of the slopes is more than 10º. In any case, they are attached to the concrete base with screws with dowels and metal plates;
• The insulation boards are glued to bitumen-polymer mastic. Gluing is possible if the area of ​​the surface “planted” on the adhesive composition is at least 30% of the area of ​​the insulating board;
• Insulation boards are laid with mandatory seam spacing so that weak areas are distributed evenly. Elements of the second tier, if there is one, are shifted relative to the first by at least 20 cm, both along the side and end lines;
• seams in insulating carpets wider than 5mm must be filled with heat-insulating material.

The use of rigid insulation is justified economically and technologically. It allows you not to install a screed on top of the insulation, which is mandatory for fill-in thermal insulation.

If it is necessary to construct a roof slope to completely free the surface from atmospheric water and dirt, the thermal insulation is supplemented with slope-forming devices. Most often they are made from wedge-shaped slabs of mineral wool or from similar polystyrene foam parts, less often from backfill insulation followed by pouring a cement screed. A slope on a concrete base can also be done by pouring cement and sand, which is unacceptable for forming a slope on a base made of a profiled sheet.

Additional layers of roofing material

An additional barrier against atmospheric water is installed in areas of high load. It is laid in strips along the ridge, overhangs and junctions with fillets constructed in advance, in valleys, around penetrations and points of internal drainage. It is constructed either from strips of bitumen-polymer roofing coating, or from a special self-adhesive hydrobarrier.

The construction of the roofing pie is completed by laying the rolled covering and fixing it by fusing, gluing or fastening with self-tapping screws with bushings or plates.

The presented schemes for constructing a roofing pie do not contain precise recommendations. We brought general rules, taking into account which will ensure flawless operation and long service life of the roof in the middle zone. In the case of construction in northern latitudes, the proposed options require modification.

• How long the roof will last, and whether it will be comfortable in the house largely depends on how the roofing pie for the soft roof is constructed. In this layered cake design, each layer has a specific function. For example, a waterproofing layer provides increased moisture resistance. Moreover, the number of components may differ accordingly design features roofs. The layers of the cake are laid out in a clear order, and any violation may lead to a decrease in consumer qualities.

  Bituminous materials used in the roofing process are characterized by low thermal conductivity. However, this is not enough to fully insulate the house: convection currents of warm air, rising up under the roof, take most of it outside with them. Actually, for this reason, a roof of this type is no exception, and it also needs to be insulated.

  The essence of the roofing pie is to protect residents from the effects of atmospheric manifestations and create favorable conditions for living.

  Roofing design options for soft tiles

  The class of soft roofs is formed from elastic materials with excellent waterproofing characteristics: shingles, bituminous tiles, mastics, rolled materials, membranes. They can be used for arranging roofs of any shape.

  On a note

  Not so long ago, these materials served only to protect against moisture, but today they are an excellent decorative coating. This is thanks to the refined outer surface and innovative installation methods that allow you to attach super-thin material to almost any base.

  • Roofing made of piece material - flexible tiles, has high sound-absorbing properties and is perfectly resistant to atmospheric influences. It is airtight and easy to install.
  • Mastic (self-leveling) is a waterproofing carpet with many layers, which is made from various types of mastics and emulsions.
  • Membrane (roll) coating is elastic, wear-resistant and successfully resists temperature changes and does not fade. Among the advantages of this roof, one should also note its aesthetic appearance, increased waterproofing properties.

  Each of these options has its own advantages and disadvantages, so they are chosen taking into account expediency and, of course, common sense. For example,

  • A flat roof is equipped using either roll coverings or mastic.
  • Asphalt shingles look great on large roofs that have visibility from all sides.

  

  A standard roofing cake for a soft roof contains the following mandatory components:

  • Vapor barrier. This layer of pie “stands” in the way of vapors that penetrate under the roof from residential premises and condense on its various elements, including layers of roofing pie.
  • Waterproofing. Prevents precipitation (whether melted snow or rainwater) from penetrating under the roof and premises for various purposes.
  • Thermal insulation. This layer is necessary to prevent heat loss and prevent noise and sounds from the outside, as well as wind and cold, from penetrating inside.
  • A decorative covering that simultaneously functions as a wind barrier.

  The list of layers of the roof pie presented above can be modified in order to bring the roof structure as close as possible to the ideal one. The scheme is formed taking into account several significant factors:

  • purpose of the building: residential or change house,
  • a permanent building or temporary shelter, which determines the need for a thermal insulation layer,
  • the shape of the slopes and the slope, for example,
  • Flooring made from roll materials for a flat roof allows you to install only three layers when installing a roof pie.

  

  • Waterproofing on soft pitched roof functions as an additional moisture-proof layer.

  On a note

  For comparison, we note that increased demands are placed on the waterproofing layer in the composition of the cake under metal tiles.

  For roofs with a slope of up to 18º, the moisture-protective layer covers the slopes completely; with greater curvature, it is laid partially, placing strips of the water barrier along the overhangs of the eaves, along the valley and ridge, in the abutment areas, around the exits of chimney pipes.

  • what base is chosen for the roof pie and for flexible tiles,
  • the expected type of attic, that is, will it be insulated or cold,
  • climate features,
  • layer compatibility.

  A high-quality roofing pie for a soft roof must necessarily meet the entire range of the conditions listed above.

  Roofing pie design diagrams

  There are no characteristic differences in the components of the cake for a soft roof made from different coatings, roll or piece. The sequence of assembling a multilayer pie structure is generally similar:

  • vapor barrier layer,
  • thermal insulation,
  • a hydrobarrier, which simultaneously serves as a decorative external covering and wind protection.

  The actual specifics of the device process are revealed during installation. For example, under a roofing pie for soft tiles, the sheathing must be continuous, and in addition to it, counter beams are needed. If the coating material is rolled, then the layers are laid directly on any possible base without any auxiliary elements. Therefore, special attention should be paid to the features of the installation process.

  Roll coating

  

  As a rule, materials of this type (bitumen-polymer or membranes) are used for arranging roofs that have a slight slope, about 1–12 degrees, on a base made of reinforced concrete floor slabs or galvanized corrugated sheets.

  Vapor barrier

  • For concrete bases, bitumen or bitumen-polymer vapor barrier is used.
  • When the roof slope angle is more than 6º, bitumen vapor barrier is fused; for smaller slopes, the material is laid freely without fusing or gluing.
  • If the base is made of corrugated sheets, a polyethylene vapor barrier, reinforced or unreinforced, is loosely laid along its corrugations. For slopes with a slope of more than 6º, it is recommended to glue a vapor barrier.
  • The roll covering can also be laid on a prefabricated screed. Any type of vapor barrier can be laid on sheets of plywood (OSB boards), but bitumen-polymer vapor barrier based on polyester is still considered the best.

  In principle, polyethylene can also be laid on a concrete base, but then you will also need to lay glassine as a separating layer.

  The laid vapor barrier layer resembles a kind of pallet that extends onto the parapets and adjacent walls vertically. The height of the sides should be equal to the thickness of the thermal insulation layer of the soft roof plus from 30 to 50 mm. Similar edges are also needed around roof outlets, say, chimneys or other communications.

  

  In any case, the vapor barrier layer in the roof pie after joining should be a continuous sheet. According to building regulations bitumen-containing materials are laid with an overlap along the perimeter of the strips, end and sides (150 mm and 80-100 mm, respectively) and welded using a gas torch. As for polyethylene, its strips are connected with tape.

  Thermal insulation device

  

  Although any thermal insulation materials are suitable for insulating a soft roof with a roll covering, preference is still given to mineral wool or polystyrene boards. The insulation is laid in one layer on a cement or concrete base, and in two layers on a corrugated sheet. Moreover, the joints of the elements of the upper and lower rows should not coincide.

  In single-layer insulation, the slabs have a rigidity of 40 thousand Pa with a compressibility of 10%. In a two-tier thermal insulation system, the slabs in the tiers can have different rigidities. For example, the strength indicators for the bottom and top rows can be 30 and 60 thousand Pa, respectively.

  On a note

  The rigid type of insulation in a soft roof pie was not chosen by chance, because in this case there is no longer a need to install a screed above the insulation layer, unlike backfill insulation.

  The installation of insulation in a roll roofing pie is carried out following a number of rules:

  • The insulation is attached separately from the covering laid on top;
  • If a mechanical fastening option is chosen, then each thermal insulation board is secured with two fasteners. When using a profiled sheet as a base, the insulation is fixed to steel screws equipped with a plastic sleeve. When the slope slope is more than 10º, such bushings are not needed;
  • Thermal insulation is attached to the concrete base using self-tapping screws;
  • For gluing mineral wool slabs, bitumen-polymer mastic is used. It should be noted that this method only works if the glue is applied to at least a third of the area of ​​the entire slab;

  

  • They must be mounted staggered, then the weak areas will be distributed evenly. The slabs in the second tier are shifted relative to those laid in the first row relative to the sides and ends by at least 20 cm;
  • If the seams on the insulation layer exceed 5 mm, then they are filled with insulation;
  • Thermal insulation of membrane roofing has some features. If measures are not taken, the plasticizer will gradually migrate into the polystyrene thermal insulation layer, and this will lead to a decrease or even loss of the consumer characteristics of the membrane much earlier than the manufacturer guarantees. Therefore, a separating layer is needed between these layers. Fiberglass or geotextiles are most suitable for this;

  A similar intermediate layer will be needed when constructing a serviceable flat roof, when polymer material is laid over a bitumen vapor barrier.

  • Installation of thermal insulation slabs on corrugated sheets is usually carried out on a prefabricated screed. However, if the thickness of the insulation is twice the corrugation pitch, the insulation can be laid directly on the polyethylene film.

  There are areas of increased load on the roof: abutments, overhangs, penetrations and others. In these areas, an additional water barrier is required in the form of roofing strips or a special self-adhesive waterproofing material.

  

  The construction of the pie is completed with flooring roll material. It is fixed in different ways: by fusing or gluing or fastening with self-tapping screws.

  One of the options for mounting a pie

  • The base is cleaned of dirt and debris, remnants of the old roof. Sometimes, if necessary, the base is additionally washed and then dried.
  • Lay the prefabricated screed. To ensure ventilation, gaps of 3 mm are left between its elements made of plywood sheets or OSB boards, and a little more, up to 5 mm, from scrap boards.
  • The vapor barrier is fixed to the surface of the walls on triangular wooden slats, which are pre-treated with an antiseptic.
  • Lay the underlay carpet and attach it along the perimeter to fillets to cover the joints.
  • An initial layer of coating is laid, then an additional hydrobarrier is applied, then a second layer of flooring is applied.

  Roof pie under soft tiles

  

  Cold attic option

  Laying a roof pie for an uninsulated attic is incredibly simple.

  

  The simplest diagram looks like this.

  • A counter beam (section 5 * 5 cm) is nailed across each rafter using two rough nails. The distance between the counter beams is determined by the pitch of the rafters. The standard pitch of the rafters is taken to be 70-90 cm; counter beams for this case are nailed every 30 cm;
  • A continuous sheathing is placed on the finished frame made of counter beams. Installation is carried out staggered so that cross-shaped joints do not form. The sheathing elements should rest with their edges on the counter-bars.

  

  • The roofing pie under soft tiles in the design of a cold attic does not have a thermal insulation component, so the next step is to lay self-adhesive waterproofing. The method of flooring depends on the steepness of the slopes. With a slope of 18º or more, the hydraulic barrier should cover only areas of increased load, for example, valleys or junction areas. On less steep slopes, the roof is completely insulated.
  • Soft tiles are laid on the waterproofing layer.

  For a continuous sheathing constructed from boards, a counter-lattice is not needed at all. The boards are attached directly to the rafters, maintaining a 3 mm gap between them.

  Warm roof installation

  

  It is more difficult to make a roof pie under soft tiles with insulation. In addition to thermal insulation, you will also need to install a vapor barrier. This layer will protect the insulation and wooden frame roofs from condensing moisture. This is very important, considering that moisture accumulated under the roof sharply reduces the insulation characteristics of the insulation and over time leads to rotting of the wooden frame elements. In addition, ventilation is also necessary, which in turn also helps remove condensation from the under-roof space.