Roofing pie of a pitched roof. How to arrange a roofing pie under a soft roof: general principles and analysis of construction options Pitched roof pie

In most cases, the soft roof pie looks like this:

• Waterproofing or diffusion layer;
• Ventilated space;

When installing the material, it is important to follow the specified order. Below we will analyze each of the elements in detail and tell you how to choose and install them correctly.

1. Wall laminated timber
2. Under-eaves board
3. Sliding support for rafters
4. Add. lathing for insulation
5. Ventrijka
6. Lining
7. Rafter leg
8. Anti-mosquito net
9. Roofing film
10. Gutter
11. Lathing
12. Counter-lattice
13. OSB board
14. Roof covering bituminous shingles
15. Underlay carpet

The design of the roofing pie may vary depending on what result you want to achieve. So, if you are planning to arrange a “cold” attic, then the thermal insulation layer is excluded. Otherwise, the structure of the pie will be approximately the same as for an insulated roof.

It is important to ensure that each of the layers described above is installed in accordance with the necessary requirements for quality, reliability and safety. If individual parts of the entire roofing structure are laid incorrectly or selected without taking into account the climate zone in which the building is located, you risk the quality of the roofing system as a whole. Sometimes such miscalculations can be corrected by local repairs, but more often, to correct them, you will have to replace the entire structure of your roof.

Basic elements of a roofing pie

So, we understand what the design of a roofing pie should look like, now let's look at each of the elements in detail, paying attention to the features and important aspects.

For options with an uninsulated roof, a vapor barrier is not needed, but if the attic or other room under the roof is residential and heated, you cannot do without a vapor barrier - otherwise, the insulation will pick up moisture formed as a result of condensation. Rafters are used to attach the vapor barrier film. Vapor barrier film is produced in rolls - the roll is spread along the ridge with an overlap. The amount of overlap is approximately 15 centimeters. The easiest way to attach this material to the rafters is with a construction stapler. One more point: all joints must be glued with special tape and during installation, do not stretch the vapor barrier film, let it sag a little (literally 3-5 millimeters) between the rafters.

Advice! To calculate the distance between the rafters, proceed from the weight of one square meter of the future roofing cake.

These elements increase the strength of the structure and serve as ventilation, preventing rotting of the rafters. First of all, the counter-lattice bars are installed - it is on them that the main layer of the sheathing is laid, and the gap formed between these two layers will serve as ventilation. The construction of a roofing pie implies that at this stage you already know what roofing material you will use. If you are going to roof with asphalt shingles, you will need a continuous sheathing. This layer is made from OSB, plywood, and so on. The surface must be perfectly smooth, even, and have a minimum number of joints.

Advice! To enhance the strength of the structure, OSB sheets (they are the ones recommended for soft roofing) must rest on all sides on the rafters or counter-lattice. Sagging will cause the structure to lose strength.

Let us repeat that a layer of insulation is only needed if you are planning a warm room or a heated attic under the roof. Choosing insulation is a responsible matter, because almost 30% of the heat escapes through the roof, which means that correctly selected insulation will help optimize the cost of heating the space. The best option for insulating a roofing pie is mineral wool insulation based on glass wool or basalt. Such materials are convenient to use, because they can be laid even in hard-to-reach corners, without forming joints and, as a result, cold bridges. Remember that high-quality insulation for roofing must fulfill its main function - to protect against high and low temperatures. The minimum thickness of insulation is considered to be 150 millimeters, but for regions with very cold winters, building codes provide for an increase in thickness to 200 millimeters or more.

Since the roof is the main obstacle between the premises of the house and precipitation, it is difficult to imagine installing a pie without a well-thought-out waterproofing system. If you are installing a soft roof, it is better to choose diffusion membranes. These membranes have an excellent property - they release steam to the outside, but do not let moisture in from the outside. Thus, the steam rises up, but the roof remains solid and impregnable even for the most merciless downpours. Such a membrane is mounted directly over the thermal insulation layer, which makes it possible to make the roofing pie more compact, enhance the thermal insulation properties of the structure and save time when installing the roof.

Ventilation

Ventilation is something that a roofing project cannot do without, because otherwise condensation will quickly render the entire roof structure unusable. It is important to know that roof ventilation can be passive or forced. Passive ventilation of the roofing pie includes ventilation gaps, which are located between the layers (we talked about them when mentioning the sheathing). But forced ventilation involves equipping the roof with special devices driven by wind or electricity. A good option in this case would be roof aerators.

Materials for roofing pie

Why choose IKOPAL? As is clear from our list of roofing pie structures, the next item is, in fact, the roofing material. Each layer of the pie is extremely important, but it is difficult to overestimate the importance of the roofing material - after all, it is the one that will be in direct contact with the environment, wind and precipitation.

Bitumen shingles are a reliable solution for any structure. Here are just a few advantages:

• Used for any, even the most severe climate;
• Provides good sound insulation;
• Withstands significant snow and wind loads;
• Used on roofs of complex configuration;
• Easy to install, there are no problems with local repairs, if necessary (the amount of waste during the installation process is minimal);
• Looks aesthetically pleasing and stylish.

Important! To install most types of soft roofing, the roof slope must be at least 11 degrees.

Bitumen has all these qualities. This is a modern, convenient and, most importantly, reliable roofing material; it is ideal for installing new roofs and repairing old ones. High installation speed can significantly reduce construction time.

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A modern roofing pie should retain heat in the winter, as well as promote heat supply in the summer. Water vapor from the room should not penetrate into the roof structure. An important function of the pie is to remove water vapor from the room, which sometimes seeps into.

The composition of the roofing cake must include several layers. In this case, the sequence of elements looks like this:

• interior decoration;
• vapor barrier layer;
• thermal insulation material;
• moisture insulation;
• clearances for ventilation;
• surface anti-icing system;
• roofing material.

Roofing pie structure: vapor barrier insulation

The vapor barrier layer prevents water vapor from entering the thermal insulation layers from the room. When installing a roofing pie, this layer is the first thing to be installed. Usually the layers are counted from inside the room. The vapor barrier film is laid using the overlap method. Then, it is fastened with a special connecting tape. This tape ensures the tightness of the vapor barrier layer.

The modified materials will include a layer of aluminum foil. With its help, the fire resistance and thermal insulation characteristics of the roofing pie are increased. But do not forget that there must be an air gap between the film and the insulating layer. Note that due to its thickness of 2 cm, installation work will become additional complex, and the design will require significant financial costs.

Roofing pie structure: thermal insulation layer

An important quality of roof insulation is vapor permeability. In other words, the material must freely allow water vapor to pass through. Those, in turn, penetrate through the vapor barrier. As a rule, such characteristics are inherent in mineral wool materials. It is very important that mineral wool slabs do not deform over time. The type of construction affects the insulation. So, you can insulate the ceiling of the upper floor or the fencing of the structure (roof).

Please note that the insulation does not have heating properties. It simply helps trap air in its fibers. This layer acts as thermal insulation.

When moisture gets on the thermal insulation layer, the material immediately loses its properties. This is due to the fact that it is forced to retain water. And if you consider that the thermal conductivity of water is 20 times higher than the thermal conductivity of air, then the thermal insulation becomes unusable.

Tip: The roof pie should always have dry insulation.

Thanks to moisture impregnations for mineral and fiberglass boards, vapor and waterproofing are protected. But do not forget that any thermal insulation is capable, one way or another, of absorbing water. Extruded polystyrene foam - resists diffusion and capillary water absorption. However, its cost may scare off budget-conscious buyers. The material is more expensive than mineral wool and fiberglass.

The technology for laying roof insulation involves installation work. Moreover, they should be carried out after reducing the wood moisture content to at least 18%. If this is not taken into account, then moisture from the wood will penetrate into the insulation. This is fraught with big troubles, because the waterproofing layer prevents moisture from leaving the roofing pie.

Ventilation and anti-icing systems

The advantage of a ventilated roof is the separation of insulation and roofing material.

In the ventilation device of the roofing pie, you need to follow certain steps:

1. When using a corrugated sheet, it is very convenient to arrange ventilation holes and a ridge fan. You can even cover the wavy sheet with a flat ridge.
2. Passive ventilation is not the last element. Today you can find equipment that provides forced circulation of air flows in the under-roof space.
3. Cornice boxes and ventilation outlets are installed next to the ridge. Note that any set of materials for soft roofing has a ventilated ridge.
4. The lower cornice must have special holes. These roofing elements are protected from the penetration of small birds or insects. Next, the installation of ventilated skates takes place.
5. In the absence of the above-mentioned possibility, the ventilated gaps at the top and bottom are connected to the atmosphere. For this purpose, special roof fans are used.

Roof icing is a serious problem for any owner of a country house. Therefore, very often the installation of a roofing pie includes anti-icing systems. These are a kind of heating cables, temperature sensors and other equipment.

System installation stages:

Roofing pie waterproofing device

The waterproofing material completely depends on the type of roofing material of the country house. During precipitation, moisture often penetrates into the attic. When using the attic as a non-residential space with ventilation of the space under the roof, the moisture will evaporate very quickly.

But there is always a risk of damage to the wooden elements of the roof structure. It is worth noting that even if you carefully arrange the vapor barrier, elements of water vapor will still penetrate into the insulation. Under these conditions, it is advisable to use a waterproofing layer that absorbs or transmits water vapor. When installing a waterproofing film, you need to know exactly the sides of the material. One of its sides should be directed towards the insulation, the other towards the roofing material. Otherwise, the roofing pie will be completed with errors.

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, a roofing cake for metal tiles is no exception; it, like other cakes from various roofing materials, is made 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 covering.

Warm roof roof

In order to reduce noise, as well as to reduce the empty space under the roof, a warm roof is installed. The roofing package 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 of 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 to 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 24-32mm thick (depending on the type) is mounted on top of the counter-lattice.

Sooner or later, everyone who has already started building their own house or is just thinking about building it has to deal with such unfamiliar words as “insulation circuit”, “rafters”, “steam and water barrier”. In search of answers, the concept comes that the roof is not only the visible part, which has an unusual shape and a beautiful coating. This turns out to be a multilayer structure with many main and auxiliary elements. And the longevity of the roof and the house as a whole depends on how well they work.

What is a roofing pie

It would seem such a strange combination - a confectionery product and a construction term. But it is precisely this that fully reveals the structure of the roof, its significance and tasks - to protect the house from negative natural influences and to ensure a good microclimate in residential premises. And this is achieved thanks to numerous layers of insulating materials and additional components.

The roofing pie, where each element is in its intended place and performs the functions assigned to it, is the main filling of the roof. And the functionality of the roof depends on the correctness of its installation, namely the order of arrangement and technology for fastening the layers.

A standard roofing pie consists of several layers arranged in a strictly defined order.

Video: roofing pie of a pitched roof, the role of insulating layers and ventilation

Roofing pie composition

The roof structure is equipped in two versions - for a cold attic space and for an insulated roof.

Cold roof installation

A roof is considered cold if the space under it remains uninsulated and most often unused. There are times when it is deliberately left cold, for example, to store canned fruits, vegetables and produce.

For a sloping cold roof, the roofing pie is divided into two parts located in different zones.

The layers of the roofing pie of a cold roof are divided and arranged in different zones - on the slopes and ceilings

On the slopes, the layers of the roofing cake (from the inside out) are as follows:

• waterproofing laid along the rafters;
• counters and sheathing;
• roofing covering.

On floor slabs (from interior to attic):

• ceiling lining;
• vapor barrier;
• insulation.

For flat attic roofs, the principle remains the same, except for the upper attic floor, on which waterproofing is usually not laid. Soft roofing, most often used on flat roofs, is itself 100% sealant. Yes, and they lay it on a solid concrete base or corrugated sheets, on which they arrange an expanded clay layer along the slope and a leveling cement-sand screed. This is quite enough to prevent any roof leaks.

The only exceptions are structures in which the attic roof is supported by a system of wooden beams. In this case, waterproofing material is additionally laid on top of the wooden elements.

The waterproofing layer on flat attic roofs is laid only in structures with a wooden base

Cold roofs are considered the most correct, since they provide free air circulation, which, if necessary, is supplemented with roof aerators. Such a roof can last up to 100 years, keeping the rafter system intact and suitable.

Insulated roof

For an insulated roof with an attic space being used, the roofing pie is characterized by the fact that all its components are combined into an integral structure with a strictly determined alternation of layers and the arrangement of ventilation gaps.

If you look from the inside of the room, the arrangement of the layers of the roofing pie looks like this:

When installing an insulated roof, special attention must be paid to the tightness of the joints of all roofing layers in places that are difficult to access for installation and therefore especially problematic - walls, ventilation risers and chimney pipes, roof window frames and valleys. Violation of the tightness is fraught with the appearance of cold bridges and heat loss through the roof.

Let's take a closer look at the layers of the roofing pie of a warm roof and their purpose.

Interior finishing of the roof space

The under-roof space in the form of an attic or attic is an interesting structure. Even being luxuriously finished, it does not look solid. Often, sloping walls and ceilings give this room an aura of romance, airiness and lightness.

When choosing a finishing material, you need to take into account that the rafter system, under the influence of wind and snow loads and seasonal temperature changes, will still show signs of deformation. They will be very small and invisible, but you will have to take them into account so as not to crack the joints on the cladding over time.

The main task of the finishing layer of the roofing pie is to refine the under-roof space and protect the next layer - the vapor barrier - from moisture from the premises of the house. For cladding they mainly use:

• blockhouse or clapboard;
• drywall (gypsum plasterboard);
• MDF or OSB boards.

Drywall is perhaps the most popular material for interior decoration, especially on complex sloping roofs. It is easy to cut, making it possible to sew up elements of the most intricate shapes. In addition, drywall creates a perfectly smooth surface, which can subsequently be easily painted or applied with beautiful decorative plaster. In addition, you can make any decorative elements from it and make the interior of the room incredibly attractive.

You can decorate an attic space with plasterboard facing elements and even divide it into zones

Attics and attics lined with OSB or MDF boards look no less beautiful. This material is as smooth as drywall, but much stronger.

Cladding the under-roof space with moisture-resistant MDF boards using the play of light allows you to make unusual bright accents on individual interior elements

The big advantage of drywall and slabs is that hidden wiring can be installed under them, but with the use of fire-retardant corrugations. But when covering with wood, the electrical wiring will have to be made open and then decorated. But, despite this, many still prefer wooden linear materials - lining and blockhouse with imitation of rounded logs or timber, as environmentally friendly materials that do not go out of fashion.

An attic lined with dark clapboard in a classic style in combination with light walls looks strict and elegant

The main enemy of any insulation is steam. Rising from heated rooms, it meets cold air in the under-roof space, as a result of which it condenses and settles in the layers of the roofing pie. To prevent this, a vapor barrier layer is laid between the heat insulator and the inner lining. But in addition to protecting the insulation, vapor barrier also retains heat in the under-roof space, which is especially important in the off-season.

As a standard option, a two-layer polyethylene film with a reinforcing mesh of polyethylene strips between the layers can be used as a vapor barrier.

The vapor barrier layer in the roofing pie is located between the inner lining and the insulation

When choosing a vapor barrier material, you need to pay attention to the following points:

1. The tensile strength of the film or membrane. The insulation puts pressure on the vapor barrier material, as a result of which the thin film can tear, and then the condensation will do its dirty work.
2. Vapor permeability indicator. If this coefficient varies from 0 to 90 g/m² per day, then it is a vapor barrier material. A coefficient over 100 indicates a vapor-permeable waterproofing material, which is not suitable for constructing a vapor barrier layer.

There is no universal “vapor and waterproofing”. Vapor barrier films or membranes and vapor-permeable waterproofing are different concepts, and their incorrect use will result in bad consequences for the entire house.

Thermal insulation material for roofing pie

Just as a person needs clothing, a home needs protection from heat and cold. Therefore, thermal insulation is the simplest and most effective method of energy saving. Good thermal insulation materials can reduce heat loss by up to 70%. In addition, they provide:

• indoor comfort;
• effective noise and sound absorption;
• saving costs on heating and air conditioning at home;
• increasing the service life of main structures;
• reducing carbon dioxide emissions into the environment.

In private housing construction, mineral wool insulation is widely used - inexpensive, perfectly retains heat and coolness, and is chemically and biologically resistant. In addition, they have a fire resistance limit of more than 1000 °C established by regulations.

When insulating the attic, mineral wool is placed in the spaces between the rafters

Recently, new insulation materials have appeared on the construction market.

1. URSA staple fiberglass is a wide-profile insulation that can be easily installed in hard-to-reach places.
2. Extruded polystyrene foam, characterized by high heat and sound insulation, ease of use and long service life - up to 100 years.
3. Sprayed insulation materials, which are applied using special equipment and form an even layer on a surface of any geometry.
4. Polystyrene foam is the most budget-friendly insulation option.

Polystyrene foam is widely used to insulate roofs and walls of a house because it is easy to install and inexpensive.

The owner decides which insulation to choose. They all deserve attention. However, to obtain the maximum effect, it is necessary not only to correctly select insulation according to the roof structure, but also to follow the installation technology offered by insulating coating manufacturers.

Roof waterproofing

The next layer of the roofing pie is waterproofing, located above the insulation with an air gap for ventilation of the latter. Waterproofing is a necessary measure to protect the entire roof structure from precipitation. Waterproofing material is laid along the entire roof, starting from the end of the rafters to the ridge itself, with the organization of air outlet so that moisture does not remain in the insulation.

For roof waterproofing, reinforced film is often used, which is laid along the rafters with a slight sag

The waterproofing film is laid with a sag between the rafters of no more than 20 mm. Membrane materials are mounted directly on the insulation without sagging, which significantly reduces the wind load.

Waterproofing materials must have:

• mechanical strength;
• good moisture resistance;
• elasticity and heat resistance.

In addition, it is not necessary, but desirable, that they have heat-saving qualities. Protection from cold and moisture in one insulating material is an excellent solution for the home.

Ventilation gaps in the roofing pie

When arranging the roof, you need to remember - it must breathe well, regardless of its design. Otherwise, the roof will “cry” and no insulating layers will help. Warm roofing is usually installed over attic spaces, which do not provide the necessary space for free air circulation.

There are all conditions for natural ventilation of a cold roof in the attic, but when arranging a warm attic it is necessary to provide ventilation gaps

Therefore, when constructing an insulated roof, it is necessary to provide for the installation of three ventilation gaps in order to ensure full natural ventilation of the under-roof space:

1. Eaves channel along the entire length of the overhangs for the flow of cold air under the roof.
2. The space between the counter-lattice and the sheathing for the movement of air along the roof.
3. Ridge vents through which warm air will flow out.

To enhance draft, natural air circulation is supplemented with ventilation roofing components - aerators, valves or turbines.

Roof aerators supplement the insufficient natural ventilation of the under-roof space

Roof anti-icing system

The age-old struggle with ice and snow can be solved quite simply these days. For this purpose, modern roof anti-icing systems have been created, which have replaced mechanical snow removal using a shovel and crowbar and chemical treatment. Unlike the last two methods of snow removal, in which there is a high probability of damage to the roofing, anti-icing systems are completely safe and highly effective. However, they have their drawbacks:

• additional energy consumption;
• high cost;
• the need to attract professionals who will competently carry out calculations, installation, testing and debugging of the entire system.

Video: heating the roof, gutters and gutters with electric cables

Roofing material

Every developer wants to see his home bright, individual, eye-catching and impeccable in everything. And if the facades are still clad in a moderate manner, then the roof more than compensates for this. Fortunately, modern roofing materials are a haven of imagination that can give any home style and character.

A huge variety of textures and colors reigns in the world of roofing decking today. If you want a roof to match the young greenery or like a bright orange color - no problem. Red, lilac, red, yellow, blue - whatever your heart desires.

The rich blue color of the roofing covering made of bitumen shingles looks beautiful against the background of a light facade

But when choosing a roofing covering, it is worth remembering that the key requirements still remain:

• fire resistance of covering material;
• wear resistance, strength and durability;
• ease of installation and accessibility.

And only after this comes the turn of aesthetic criteria.

Video: review of popular roofing coverings, their pros and cons

Types of roofing pie

It should be noted that the structure of the roofing pie may change. Depending on the roofing covering and the type of roof, some layers are absent or partially laid, while others appear additionally, which is dictated by the characteristics of a particular structure.

Types of roofing pie depending on roofing covering

Let's consider the composition of the roofing cake for the most popular covering materials.

Corrugated sheeting is the most unpretentious material, so it won’t be difficult to arrange a roof for it yourself. Particular attention should be paid to two layers - thermal insulation and sound insulation.

The insulation is placed strictly in the space between the rafters. To improve the performance of the heat insulator, it is covered with a windproof film that does not allow steam to pass through, and a lath is stuffed onto which corrugated sheets are already mounted. The pitch for the sheathing is chosen according to the size of the sheet and the slope of the roof, taking into account the overlap of one or two corrugations. Features of a metal roof require:

1. Mandatory installation of ventilation gaps between the insulation layer and the roof covering. The size of the ventilation ducts is not fixed, but not less than the thickness of the beam sheathing (3 cm).
2. When assembling the sheathing, it is advisable to install additional stiffening ribs, which will significantly extend the operation of the roof.

Installing insulating strips of felt or polyethylene foam along the rafters will help solve the problem of sound insulation.

Standard composition of the roofing pie for corrugated sheeting:

Roofing pie for flexible tiles

Soft tiles have a great advantage - it is an absolutely waterproof material. Therefore, among the layers of the roofing cake there is no waterproofing, but additional layers appear - a solid base made of moisture-resistant particle materials and an underlay carpet.

The pie is arranged under the tiles by alternating the following layers:

The original roofing materials of the Ondulin company do not require the installation of a roofing pie as such. They don’t care whether there is an insulating layer and vapor or waterproofing films or not. They themselves reliably protect the roof from bad weather if the rafter system, sheathing and, if necessary, counter-lattice are installed correctly. In addition, branded materials retain heat well. This is what we talked about in the “Waterproofing” section: two significant functions in one material - an ideal solution to the issue of waterproofing and thermal protection.

Of course, in our frosty winters in permanent residences, it is necessary to insulate the roof. Nevertheless, there are no special requirements for insulation under ondulin. Except for one thing - its thickness must comply with SNiP standards. For example, for Moscow and the region this is at least 25 cm of mineral wool material.

The order of layers from the roofing to the inside of the room:

Roofing pie for metal tiles

The seam roof with a matte gray finish harmonizes beautifully with the wooden architecture of the house in the same color scheme

Roofing pie for standing seam roofing:

Video: installation of seam roofing

The pitch of the rafters for a sloping roof is determined by the roof structure and covering material, the recommended value is from 600 mm

Video: rules for installing roofing pie

The roof structure is far from the simplest element of a building. As a rule, it consists of several layers of different materials that provide the proper level of noise, vapor and heat insulation. And, of course, they protect the house from precipitation at any time of the year.

However, different types of roofing require the appropriate types of materials. Experienced builders often know all time-tested options. And in the case of a roof pie under metal tiles, a number of additional nuances must be strictly observed.

In this article

Type No. 1: cheap and cold

A rational option if the roofing pie is calculated for outbuildings, gazebos or for housing in warm regions, where snow and cold are known only by hearsay.

The design of a cold roof is very simple and consists of only five elements:

1. Rafter system.
2. Waterproofing film. The hydraulic ventilation gap must also be taken into account.
3. Counter-lattice (wooden slats, planks or bars).
4. Lathing (bars or edged boards).
5. Metal tiles.

Easy to install, more budget-friendly. However, at the same time, you will have to forget about heat and sound insulation from the outside.

Type No. 2: minimum noise, maximum heat

An option for most private houses whose owners do not want to hear booming noise during rain and freeze when cold weather arrives.

What is included in the design:

1. Vapor barrier, which is installed on the inside of the roof.
2. Rafters with longitudinal purlins are the main load-bearing element of the structure.
3. Thermal insulation material is installed between the rafters and purlins. Gaps for ventilation must also be provided.
4. Waterproofing is installed above the insulation surface - a film/membrane that allows steam to pass through from the inside, but does not allow moisture to penetrate from the outside of the roof. The distance of waterproofing from the insulation should be approximately the same as from the metal tile - 40-50 cm.
5. A counter batten is installed parallel to the rafters, pressing the waterproofing. It also serves as a support for installing the sheathing.
6. The sheathing is where the metal tiles will be mounted. It is recommended to use beams with a design cross-section of 50x50, the fastening spacing along the slopes is 35-45 centimeters.
7. Metal tiles.

Such a metal roof pie will cost a little more, and installation will be more difficult and longer. However, the correct installation of these components will reliably protect against cold and precipitation. Such a roof will retain heat much more effectively than its “cold” counterpart.

Rules for selecting metal tiles

There are different tiles and tiles. Even if the material seems to be the same type. The current market offers customers a wide variety of options with any characteristics, appearance and, of course, price.

One of the main parameters affecting the strength of a material is the thickness of its metal base.. Typically, roofing pies use sheets no thicker than 0.4-0.5 mm. Reinforced options are guaranteed to affect the reliability of the roof, as well as the magnitude of its load on the rafters. Be sure to take this into account when calculating the roof frame.

In addition, any metal tiles must be covered with a protective layer during manufacture.. It provides resistance against aggressive external influences. And how effective this protection will be is determined only by the quality of the layer itself. Which will directly affect the cost of the tiles.

The height of its waves will give additional strength to the material. However, do not forget that galvanized sheets of the same length are used for any tile. Therefore, the greater the height of these waves, the material becomes not only more stable, but also gives less useful width.

Finally, the large length of the sheets greatly simplifies the entire installation process. In addition, the risk of leaks is reduced. On the other hand, this approach increases the chances of longitudinal deformation of the roof.

You need to know this from the very beginning

When assembling the roofing pie, special attention is paid to two points: the correct location of the waterproofing and ventilation gaps.

Many owners try to save on materials by purchasing cheaper mineral insulation, ecowool or glass wool instead of waterproof foam. With this choice, the costs will indeed be significantly lower. But then it is the thermal insulation that will become the most vulnerable point in the entire structure. After all, these materials are highly susceptible to the harmful effects of moisture. By “destructive” we mean the loss of its heat-saving properties up to 80%. Therefore, it is strongly recommended not to skimp on at least waterproofing.

However, not a single roof of a private house can be completely protected from moisture penetration into the roofing layers. For such cases, gaps are provided between the thermal insulation and the upper level of the cake, the dimensions of which are usually 30-40 mm. The air flow should go from the roof overhang to the ridge.

Slightly shorter gaps (10-15 mm) should also be present between the tiles and the waterproofing.

Installation technique

After calculations and selection of all necessary materials, the most important stage comes - installation of the roofing pie. Both types have their own characteristics, so when choosing a “cold roof” you can immediately proceed to the third stage. In the case of a “warm roof” you need to start from the very first point.

1. A vapor barrier layer will protect the roof from the harmful effects of steam from a warm room under the roof. Different types of vapor barriers require a certain gap during installation (which may vary from product to product). Therefore, for such cases, a counter batten (thickness - 30 mm) is first installed along the joist. A vapor barrier is attached to it using a construction stapler or counter-lattice. It must be laid along the slope from its lower part to the upper. Each row of the vapor barrier overlaps the previous one (100-150 mm). Exactly the same applies to longitudinal joints.
2. On the outside of the frame, insulation is stuffed between the joists. Space for air gaps must be provided.
3. A mandatory step not only for a “warm” roof, but also for a “cold” roof. A waterproofing film is attached along the joists using a vertical counter-lattice (beam 30x50x50 mm) with a nail pitch of 30 cm. A ventilation gap is also required here - the material must sag by at least 1-2 centimeters.
4. And the sheathing is already installed on the counter-lattice. Its pitch, as mentioned earlier, should not exceed 45 cm. In valleys, ridges and various junctions it is laid completely.

Please note that all wood materials of the pie must be calibrated and dried under natural conditions before installation. Treatment with fire retardants and antiseptics is highly desirable.

Finally, be sure to pay attention to your home's roof at least twice a year.. Regular preventive maintenance and, in particular, monitoring of additional elements, joints and junctions in advance will help to avoid possible problems with the roofing pie.