What waterproofing to use for the attic. Waterproofing and insulation of the attic floor

The attic in the house has its advantages and disadvantages. Which? About this As the voting results show (), a house with an attic attracts approximately 50% of readers.

Work on insulating the attic is carried out either from above before installing the roof covering, either from below, after the house is protected from precipitation.

The first option is from above, it is more convenient to install, and allows you to carry out work faster and with better quality.

With the second option - from below, you can postpone the work and costs of arranging the attic until later.

The designs of insulated roofs in both cases are somewhat different.

Insulating the attic from above

In this article, the use of steam-wind-moisture barrier membranes in the construction of an insulated roof attic floor Let's look at the example of a system protective materials trademark Izospan. You can read about the materials of this system in the article.

Installation of an insulated attic roof

1. Roof covering
2. Wind-moisture protective film Izospan AS, AM
3. Counterrail
4. Insulation
5. Vapor barrier Izospan B
6. Rafter
7. Interior decoration
8. Lathing

Scheme for protecting attic insulation from wind, moisture and condensation in Fig. 2

Wind and moisture protection of attic insulation

Fig.2. To protect the attic insulation from wind, moisture and condensation, a ventilated gap is arranged, and films and Izospan membranes are laid below and above.

Why protect insulation from wind?

Mineral wool insulation, which is usually used for roof insulation, has an open porous structure.

Air moving in the ventilated gap easily penetrates the insulation, blowing heat out of it. The effectiveness of thermal insulation due to air infiltration can be reduced by almost half.

In addition, air moving under the influence of wind in the gap tears off and carries away particles of insulation. Weathering of the insulation occurs - over time, its density and thickness decreases, the insulation becomes a source of dust, which can penetrate into the house.

To prevent these processes, the insulation on the top side of the ventilated gap is covered with windproof, vapor-permeable material.

In addition, the wind-moisture-proof membrane (item 2 in Fig. 1) protects the insulation and load-bearing elements structures from under-roof condensation, snow and atmospheric moisture, which can be blown into the gaps of the roofing covering or penetrate into the joints of roofing sheets due to capillary suction.

The wind-waterproof membrane should not prevent steam from escaping from the insulation (vapor permeability of at least 750 g/m 2 per day).

In the construction of an insulated roof, it is recommended to use vapor-permeable materials as waterproofing and wind protection. roofing membranes Izospan AM or Izospan AS. Materials Izospan AM and Izospan AS laid directly on the insulation without a ventilation gap between them.

Izospan AM and Izospan AS are not intended for use as a main or temporary roofing covering for the period of installation.
Izospan AM and Izospan AS are laid with the white side facing the insulation.
When installing an insulated roof, Izospan AM (Izospan AS) is rolled out and cut directly on top of the insulation. Installation is carried out with horizontal panels overlapping, starting from the bottom of the roof. Overlapping panels at horizontal and vertical joints - at least 15 cm.

The stretched material can be further strengthened on the rafters with staples using a construction stapler.

On top of the material, 4x5 wooden antiseptic counter-battens are attached vertically along the rafters. cm on nails or screws. The place of the vertical overlap or the junction of two horizontal panels must be pressed against the rafters with a counter batten.

Lathing or continuous plank flooring is mounted along the counter-battens, depending on the type of roofing.

For weathering water vapor and roof condensation a ventilation gap must be provided between the outer side of the material Izospan AM (Izospan AS) and the roofing covering to the thickness of the counter-batten 4-5 cm.

In addition, to ensure ventilation of the under-roof space ventilation holes are provided in the lower part of the roof and in the ridge area for air circulation.

The material Izospan AM (Izospan AS) is fastened in a tense position so that water can roll freely over its surface. The bottom edge should provide a natural drainage of moisture from the surface of the membrane into the gutter.

Vapor barrier for attic insulation

The vapor barrier film (item 5 in Fig. 1) performs several functions at once:

1. Protects the insulation from penetration of water vapor from the attic room. From the article you can learn why, without a vapor barrier, insulation will accumulate moisture and collapse.
2. In addition, vapor barrier performs another function - it reduces heat loss.
3. The material protects the living space from the penetration of microfibers (dust) of the insulation.

Izospan B used as a vapor barrier in insulated roofs of exploited attics with various types roofing covering.
When installing an insulated roof, the Izospan V vapor barrier is mounted on the inside of the insulation on the rafters or along the rough sheathing using a construction stapler or galvanized nails. Installation is carried out from bottom to top with horizontal panels overlapping with overlap at horizontal and vertical joints of at least 15 cm.

When decorating a room with clapboard (plywood, decorative panels etc.) the vapor barrier is secured along the frame with vertical antiseptic wooden slats 4x5 cm., and when finishing with plasterboard - galvanized profiles.

The material is installed with a tight fit smooth side to the insulation, rough side down. The interior decoration of the room is attached to a slatted frame or galvanized profiles with a ventilation gap of 4-5 cm.

To ensure the tightness of the vapor barrier, it is recommended to fasten the panels of Izospan B material together with Izospan KL or SL connecting tape. Places where Izospan materials meet wooden, concrete and other surfaces are glued with Izospan ML proff adhesive tape.

Instead of Izospan B, Izospan RS, Izospan C or Izospan DM can be used as a vapor barrier when installing an insulated roof. The installation diagram is similar.

Heat-reflecting vapor barrier for attic insulation

Can be used as a vapor barrier heat reflective vapor barrier: Izospan FS; Izospan FD And Izospan FX. The material is mounted on the inside of the insulation (on the rafters or along the rough sheathing using a construction stapler or galvanized nails) with the metallized surface facing the room.

There must be an air gap of 4-5 in front of the metallized surface of the membrane cm. Only in this case does it happen reflection of heat flow, which increases the thermal resistance of the coating. Installation is carried out with horizontal panels overlapping, starting from the bottom of the roof. Overlapping of material at horizontal and vertical joints - at least 15 cm(Izospan FX - end-to-end).

Vapor barrier sealing

The vapor barrier layer prevents the insulation from getting wet. In places with defective vapor barriers, the insulation becomes saturated with moisture in winter. These places begin to freeze, fungus and mold appear on the walls, and the insulation itself gradually deteriorates.

Careful sealing of the vapor barrier layer - necessary condition long and reliable service of thermal insulation and wooden roof parts. The same thing happens if water gets into the insulation from above. But developers, due to misunderstandings, often neglect the threat of moistening the insulation from below, from inside the room.

TO wooden parts The vapor barrier film is secured using staples with a stapler. TO metal profiles The sheathing is glued with double-sided tape. The vapor barrier film is laid with 10 cm. overlap. The film should not be stretched too much, since the film changes its size when the temperature changes.

The joints of the film are taped with tape made from a material with a similar coefficient of thermal expansion. The junction of the film to the walls is more reliable press with planks and apply sealant underneath them to the wall, since adhesive tapes do not adhere well to rough surfaces.

It is more reliable to make film joints over a hard surface, where, in addition to gluing, the joints can be pressed with spacers, sheathing bars, secured with staples, etc. Passages through the vapor barrier of smoke and ventilation pipes are also carefully sealed. Don't neglect sealing plumbing piping and electrical wiring.

Choosing insulation for the attic

To insulate the attic, it is recommended to choose fireproof mineral wool insulation. In summer the roof can heat up to 60 degrees C, and in winter through thin layer wet insulation can lose up to 25% of the heat. Therefore, it is so important to lay a sufficient layer of insulation and prevent it from getting wet.

Modern energy saving standards recommend providing the attic roof with a heat transfer resistance of 4-5 m 2 *K/W. In order to obtain the economically justified heat transfer resistance required by the standards, it is necessary to lay layer of mineral wool insulation 20 - 25 thick cm.
How to calculate the thickness of attic insulation

The height of the roof rafters, as a rule, does not exceed 15-18 cm. Additional layers of thermal insulation are placed between the bars of the internal sheathing, or bars of the required height are nailed to the rafters from below.

Buy insulation in your city

Mineral wool

Soundproofing the attic

In addition to good thermal protection, the outer fencing of the attic must provide sufficient sound insulation of the attic rooms from airborne noise. People sleeping in the attic should not be awakened by the impact of raindrops or hail on the metal roof covering.

Therefore, the external fencing of the attic is subject to fairly stringent sound insulation requirements.

In accordance with current standards, the airborne noise insulation index of the external fence of the attic - Rw, must be at least 45 dB. The same mineral wool insulation is used as sound insulation and against airborne noise as for thermal insulation.

To achieve this indicator in the external enclosures of the attic the thickness of mineral wool sound insulation must be at least 250 mm. If the thickness is less, then the sound insulation will not meet the standards. Thus, the thickness of the mineral wool thermal and sound insulation of the attic is selected based on two conditions: thermal insulation and sound insulation. The thickness is the greater of the two indicated.

Insulating the attic when working from the inside

Features of the attic insulation design when performing work from the inside, under the installed roofing, are clearly visible in the figure below (to zoom in, press the Ctrl and + keys simultaneously):

If the ceiling of the upper floor in the house is made according to wooden beams, then the floors and partitions in the attic should be light in weight and provide the necessary sound insulation. In this case, it is best to make it with gypsum fiber sheets (GVLV) or other boards, and also install it. Just such an option is shown in the figure.

Please note that the frame partition should cut through the attic sheathing as far as possible, and the base of the partition should rest on the subfloor. This design will prevent sound transmission to the adjacent room bypassing the partition, through the finished floor covering and attic cladding.

If special measures are not taken, then soundproofing of attic rooms with frame external walls, partitions, floors and ceilings will be insufficient.

If the ceiling of the upper floor in a house with an attic is made of reinforced concrete slabs or, then on such a floor it is more profitable to lay partitions made of brick, as well as light gypsum or concrete building blocks.

Watch the video, which clearly shows the thermophysical processes in an insulated roof and the basic installation rules. While watching the film, remember the need for wind protection with mineral wool insulation.

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Back in 1630, the architect Mansart proposed using attic space for residential purposes. This is how the attic appeared - a comfortable room. And it will become even more comfortable if you insulate the attic from the inside. Collateral effective thermal insulation are following rules: creation of a continuous insulation contour, provision of waterproofing and vapor barrier, arrangement.

Materials used

Not all insulators are suitable for do-it-yourself attic insulation. Optimal choice– slabs made of stone wool. They are fire resistant and vapor permeable, do not deform and almost do not absorb water. And here polystyrene foam boards and builders try not to use fiberglass mats. The former cannot be proud of their fire resistance; the latter, over time, lose thermal insulation properties.

Most often, in this case, lightweight materials are used so as not to put a large load on the main structures. Therefore, when making it, they prefer to use wood or a thin cold-formed metal profile.

During installation, you cannot take the product according to the exact cell size of the rafter system frame. If the insulator is calculated based on the size of the cell, it will not perform its functions: the material will “dry out” and small cavities will form through which the cold will seep.

When a slab of the selected insulation is taken with a reserve, it fits tightly into the space between the rafters and even after “drying out” the cotton wool fills the entire cavity.

We make thermal insulation of slopes

The roof, under which the attic space itself is located, is supported by a structure: sheathing and rafters, which are installed in increments of 600-1000 mm. Consequently, stone wool slabs are placed in spacers between the rafters. If the thickness of the insulation is greater than the cross-sectional height of the rafters, wooden beams treated with an antiseptic are attached to them using screws.

To remove moisture that has entered the under-roof space, an air gap is left between the roof and the insulator. If the roof is made of galvanized corrugated sheets, tiles or metal tiles, then the gap thickness should be 25 mm. If the roof is laid flat sheets(asbestos-cement, galvanized, soft bitumen tiles), a gap of at least 50 mm is required.

Builders also recommend taking care of a layer of windproof, vapor-permeable material. If we are talking about building a house from scratch, windproof film mounted on top of the rafters wooden blocks. In the case where the attic is being landscaped on an existing attic, the wind barrier layer is attached to the rafters either with nails or wooden slats.

Vapor barrier

It is very important when starting to insulate the slopes, to properly do the attic vapor barrier with your own hands. This is necessary to ensure that water vapor does not penetrate from the living space into the under-roof space.

As a rule, the roof does not allow water vapor to pass through well, so condensation forms on the inside and on the sheathing due to temperature differences.

Over time, this can lead to negative consequences: destruction of the frame of the structure, a decrease in the level of thermal insulation, and the appearance of leaks on the ceiling.

To prevent this from happening, the thermal insulation layer is additionally protected with a vapor barrier material (ordinary polyethylene film or a membrane specially designed for this purpose will do). It is laid on the inside of the slabs with an overlap of 150-200 mm, and then secured with wooden slats.

The vapor barrier material must be airtight. By the way, some thermal insulation materials have a special base made of foil. It allows you to protect the roof from condensation: during installation, you need to make sure that the insulation is placed with foil inside the room.

Finishing

It will be correct to finish the attic only after all procedures related to the thermal insulation of the slopes have been completed. The inside of the attic floor can be finished with plasterboard, plywood, clapboard or boards.

Finishing material attached to bars or metal profiles. If the insulation is not equipped with a vapor barrier film, but with vapor barrier foil, the finishing material is fixed at a distance of 5 cm from the foil. This allows you to reduce heat loss.

It must be remembered that the outflow of heat in the attic occurs not only through the slopes, but also through the end walls (gables). Wall insulation attic space carried out in two ways. The most effective is external (when the heat-insulating layer is located on outside pediment). This option is acceptable for houses built from timber, logs, brick and foam concrete.

But external insulation is not always possible. Then the attic floor is insulated from the inside. In terms of technology, it is not much different from insulating a conventional frame wall:

• a windproof layer is installed on the frame beams, after which insulation is placed;
• if the frame is less thick than the insulating layer, then additional bars are installed;
• After the installation of the insulator is completed, the wall is covered with a vapor barrier.

Please ensure that the vapor barrier layer is not interrupted either at the gable or on the slopes. This can be achieved by fastening the panels of vapor barrier film overlapping.

Working with stone walls

For stone walls you'll have to make the system from scratch. An alternative to the above insulation materials is the use of blocks made from alabaster chips. The best option is wood fiber boards, that is, fiberboard. Fiberboard has many advantages. So, one product with a thickness of 1.2 cm is similar to a 4.5 cm brick. In addition to heat-insulating properties, it is distinguished by sound-proofing properties. The slabs are treated with an antiseptic substance, so they are not susceptible to microorganisms or mold.

In general, fiberboard is a rather brittle, lightweight and soft-to-touch material. The outer area of ​​the products has smooth surface, and the inner one is corrugated. The slabs do not react to sudden temperature changes, are quickly cut into pieces and do not deform under the influence of different loads. Wallpaper rolls are glued to the outer area of ​​the insulation, which will create home comfort on the floor.

The correct way to insulate gables with wood fiber boards is as follows:

• a slab measuring 250x122 cm is lifted to the desired area, after which it is strengthened from below with plank supports shaped like the letter “T”;
• the slab is nailed to the wall surface. Length fastening elements– more than 3.5 cm.
• Under the heads of the nails, special plates measuring 1.5 * 1.5 cm made of thin aluminum - “duralumin” - are placed.

Fastening is carried out in a checkerboard pattern and so that the caps are buried in the material, otherwise the surface will not be smooth and this will ruin the finish.

Working with the floor

When insulating the attic, it makes sense, in addition to the gables and ceiling, to insulate the floor surface. There are two popular methods. The first involves dismantling the old coating and then laying two layers of roofing felt. Following them are placed fibreboards of certain brands. We are talking about M-20 and Pt-100. At the end, the finished floor is laid again.

The second method is based on the use of special types of carpets. First, the baseboards are dismantled, and fiberboard is nailed on top. Carpet materials are glued to the slabs. Before gluing, it is necessary to keep the products unfolded in a dry place for 14 days - this is exactly the time needed for shrinking and leveling.

Another option for preserving heat is to place another layer of thermal insulation under the already installed layer. This is done as follows:

• On the inner lining of the attic, a frame made of beams is installed, between which insulator slabs are placed (ideal stone wool). The height of the bars should be equal (or less) to the thickness of the insulation layer;
• the thermal insulation layer is protected by a vapor barrier material - it is attached to the frame bars.

Interior finishing

The inside of the attic can be finished with clapboard, plasterboard or plywood. It must be remembered that when using this particular technology, the thermal insulation of the attic is significantly reduced. effective area premises, as well as its height. The advantage is that you don’t have to dismantle the roof, so you can get to work not only in summer, but also in winter.

Insulating the attic also involves insulating the floor below it. There are times when a combined approach is the best option. It consists in insulating the ceiling on top of the existing thermal insulation. Inclined surfaces attic room are finished from the inside. In both cases, we must not forget about the thermal insulation of the gables.

So, insulating the attic from the inside is perhaps the only way to obtain a comfortable microclimate. In addition, correctly selected thermal insulation will allow you to pay less for heating even in very cold winters.

The roof is one of the main elements of any structure, and is designed to protect the walls and premises of the building from precipitation and wind, maintain a comfortable environment for the people living in the house or favorable conditions for the objects placed inside. Waterproofing film for roofing, selection and installation - such aspects always raise many questions, since the creation reliable barrier from moisture penetration will always be one of the the most important stages at

Today in the assortment of construction stores you can find a considerable variety of rolled waterproofing materials, and immediately understanding the features of a particular film can be very difficult. Therefore, in order to decide which type is optimal for the planned roofing, there is a need to take a closer look at the characteristics, as well as the features of the installation work.

The main purpose of roof waterproofing

Let us first recall that earlier, when constructing private houses, waterproofing pitched roofs was not always installed - this process was mainly carried out on flat or low-slope roofs of multi-storey buildings, and for these purposes, as a rule, roofing felt was used. The technology for mandatory waterproofing of roofs came from abroad, along with materials intended for this purpose, and it must be said that it has taken root well in the Russian construction industry.

Nowadays, the construction of a private house no longer requires the inclusion of such a stage of work in the project, since it is one of the most important for the overall protection of the structure from moisture penetration. Waterproofing the rafter system helps to avoid frequent repairs and extends the life of the building as a whole.

A protective film becomes especially important if the under-roof space is insulated with one of the types of thermal insulation materials that can absorb moisture - the same condensation that forms during temperature changes. Waterproofing material is able to reliably protect the insulation, create conditions for its free evaporation into the atmosphere or for removal from under the roof - into a properly equipped gutter, fixed along the slope on the eaves board.

In addition, no one is completely insured against leaks of the roofing covering, due to its aging, accidental mechanical damage, or even from trivial errors during installation. The waterproofing barrier will not allow atmospheric moisture to immediately, directly enter the attic and spread further, and the owners will have the opportunity to take adequate measures to eliminate the emergency situation.

Waterproofing membranes are usually sold in 50 m rolls, 1500 mm wide, and the weight of the roll can vary depending on the thickness and type of film.

Glassine

Glassine is roofing cardboard impregnated with a composition of refractory bitumen with the addition of plasticizers. Glassine is sold in rolls and is used for hydro- and vapor barrier of various building elements.

Many owners of private houses, wanting to purchase glassine, wonder what it is, a hydro- or vapor barrier material? For roofing, glassine is used in one or another capacity - it is used to vaporize the insulation on the side of the premises and to form additional waterproofing for the roofing “pie”, laying it under the roofing material.

Several types of roofing glassine are produced with different markings:

• P-300 GOST and P-300 TU - the material has average density, waterproof, is characterized as a reliable waterproofing material, but is inferior to the P-350 brand.

• P-250 is an economy class material, as it is made from low quality raw materials. However, despite this, it has high strength properties, is water and frost resistant, and is also quite elastic.
• P-350 GOST and P-350 TU - this material is the most High Quality of all brands of glassine, as it is richly impregnated with bitumen. In addition, the advantage of this material is its ability to “breathe”, therefore, when used, a ventilated roofing “pie” is created.

These diagrams present three ways to use glassine in roofing, where it is used as a waterproofing and vapor barrier layer.

• The first diagram shows the installation of glassine on flat roof as a vapor barrier layer.

1 – Roofing material.

2 – Concrete screed.

3 – Insulation mats.

4 – Glassine.

5 – Concrete floor.

• Second scheme. Here glassine acts as a waterproofing layer for the pitched roof. cold roof:

1 – Roof covering.

2 – Glassine.

3 – Solid plank sheathing.

• The third diagram represents the location of glassine in the roofing “pie” of insulated two pitched roof, in which it plays two roles at once - waterproofing and vapor barrier:

1 – Roofing material.

2 – Glassine (as under-roof waterproofing).

3 – Counter-lattice.

4 – Insulation.

5 – Glassine (vapor barrier on the room side).

6 – Rafters.

7 – Drywall (internal lining of the attic).

Breathable perforated or diffuse membranes

This type of waterproofing material provides adequate protection for the roofing system from direct penetration of precipitation, and at the same time does not prevent the evaporation of water vapor coming out from the inside, from the layers of the roofing “pie”.

High vapor permeability can be achieved due to the perforation of the material. The film is a non-woven fabric made from synthetic fibers, and is used as a wind and waterproof layer. This material can be laid directly on the insulation, which saves on the installation of counter-battens. For the material to function “correctly”, it must be secured right side to the insulation. At the same time, it should be noted that on the construction market you can find both one-sided and double-sided membranes, which, accordingly, can be laid on the insulation on either side. Therefore, when purchasing film, you need to pay special attention to this factor.

The advantage of “breathing” membranes is that they meet all the requirements for roof waterproofing and heat conservation. Well, the disadvantages, it must be said - conditional, include their high price, compared to other similar materials.

Otherwise, they can be called the most the best option for arranging roof waterproofing.

According to the level of vapor permeability, “breathable” films are divided into three categories:

• Diffuse, having average vapor permeability.
• Superdiffuse membranes have the maximum degree of vapor permeability.
• Pseudo-diffuse films with low vapor permeability, requiring mandatory arrangement of a ventilation gap between them and the insulation.

Overview of commercially available waterproofing materials

On Russian market There is a fairly wide range of materials for roof waterproofing. Some brands can be highlighted in a separate line, since they have managed to establish themselves exclusively with positive side when used in different climatic conditions - these are Ondutis, TechnoNIKOL, Yutakon, Folder Dorken Delta-Roof, DuPont, Izospan and others.

The technical and operational characteristics of some of them are presented in the table, but they also have common parameters. For example, roll size - total area material is 75 m², with a coating width of 1500 mm and a film length in a roll of 50 m.

Material name	Main technical and operational characteristics	Price, rub./roll as of May 2016
"Ondutis RV100"	It's environmentally friendly pure material, made from polymers that are inert to bacterial influences. - weight 90±10% g/m²; - vapor permeability (24 hours) - 10 g/m²; - strip breaking load 50 mm, N, (lengthwise/crosswise): 650/500.	1200÷1500
"Ondutis RS"	This is a reinforced film with good performance characteristics, which can provide wind and waterproofing protection. The membrane is resistant to ultraviolet radiation. – weight: 100±5% g/m²; - vapor permeability (24 hours): 10 g/m²; - operating temperature range: from -40 to +80°C; - UV stability without coating: 1 month; - strip breaking load 50 mm, N, (lengthwise/crosswise): 250/200.	1850
"Ondutis RVM"	This is a non-woven fabric equipped with a heat-reflecting surface, so it protects the insulation from atmospheric humidity in winter, and from overheating in summer, reflecting ultra-violet rays. Thanks to this layer, ice does not form on the roof. – weight: 125±10% g/m²; - vapor permeability (24 hours): ÷10 g/m²; - operating temperature range: from -40 to +80°C; - UV stability without coating: 2 months; - strip breaking load 50 mm, N, (lengthwise/crosswise): 250/130.	2500
"Folder Minima D98"	This material can be used if there are ventilation gaps in the structure. - vapor permeability (24 hours): 30 g/m²; - operating temperature range: from -40 to +80°C; - UV stability without coating: 2 months; - strip breaking load 50 mm, N, (lengthwise/crosswise): 550/650.	1500-1700
"Anticondensat folder"	This is an anti-condensation film, which also requires the formation of ventilation gaps. - vapor permeability (24 hours): zero; - operating temperature range: from -40 to +90°C; - strip breaking load 50 mm, N, (lengthwise/crosswise): 400/450.	1500-1700
"Yutafol D 96 Silver"	Waterproofing two-layer laminated perforated polypropylene film. – weight: 96±5% g/m²; - vapor permeability (24 hours): 18 g/m²; - UV stability without coating: 3 months; - strip breaking load 50 mm, N, (lengthwise/crosswise): 600/400	1395
"Yutafol D 110 Standard"	Three-layer reinforced, laminated on both sides, waterproofing film. – weight: 110 ±5% g/m²; - vapor permeability (24 hours): 41 g/m²; - UV stability without coating: 3 months; - strip breaking load 50 mm, N, (lengthwise/crosswise): 600/400.	2590
"Yutavek 115"	Super diffuse three-layer film. – weight: 115 ±5% g/m²; - vapor permeability (24 hours): 1200 g/m²; - strip breaking load 50 mm, N, (lengthwise/crosswise): 260/145.	4950
"Tyvek Soft"	Single-layer polyethylene waterproofing material with high vapor permeability. – weight: 60 ±10% g/m²; - vapor permeability (24 hours): 1375 g/m²; - UV stability without coating: 4 months; - strip breaking load 50 mm, N: 140.	5650
"Tyvek Solid"	Single-layer polyethylene vapor-permeable membrane of increased strength. – weight: 80 ±5% g/m²; - temperature range: from -73°C to + 100°C; - vapor permeability (24 hours): 1300 g/m²; - UV stability without coating: 4 months; - strip breaking load 50 mm, N: 250.	6950

Video: a brief overview of roofing film materials of the Ondutis brand

Installation of waterproofing film

The main difficulty of installing waterproofing rafter systems, as well as laying any roofing materials, is that the work is carried out at heights, that is, increased safety measures must be observed. Otherwise, it is not particularly difficult. To secure the film you only need construction stapler and staples.

Prices for glassine

Glassine

General rules for laying a waterproofing roof barrier

The waterproofing film is laid on top of the insulation laid between the rafters. If a “breathable” membrane is chosen for the flooring, then there is no need to provide a gap between it and the insulating material. When choosing polyethylene film Before fixing it, to create a ventilation gap, counter-battens with a thickness of approximately 30 ÷ 50 mm are fixed to the rafters, and the waterproofing material will already be fixed to them. This is especially important to consider if one of the following is used for the roof. metal coatings- or

The presented diagram shows a “roofing pie” using vapor-permeable “breathable” super-diffuse waterproofing “Izospan”. It consists of the following elements:

1 – Metal tiles.

2 – Wind-hydroprotective superdiffuse membrane.

3 – Counter rails.

4 – Layer of thermal insulation (mineral wool).

5 – Vapor barrier film.

6 – Rafters.

7 – Sheathing the attic.

8 – Lathing on which the roofing covering is attached.

• If a waterproofing film with a width of 1500 m is purchased, then its installation on the pitched rafter system is carried out from the eaves. The film is spread across the rafters, that is, along the eaves line, evenly, without folds, and secured to each of the rafter legs using staples.
• If an anti-condensation film is selected, then it is not stretched, but, on the contrary, it is laid in such a way that it sags by 10–20 mm in the space between the rafters.

This type of membrane should be located at a distance of about 40÷60 mm from the insulation, therefore, when choosing it, it is necessary to provide for the appropriate width of the rafter board and the thickness of the insulation. After laying, the anti-condensation film sheets must be glued together with special moisture-resistant tape.

The second waterproofing sheet is laid above the first and overlapped on it. The size of the overlap will depend on the slope of the roof. Recommended material overlap parameters can be found in the table below:

In some cases, for example, on short sections of the roof, where the distance between the rafters allows it, the waterproofing can be fixed vertically, but at the same time the overlap size indicated in the table is also observed, depending on the roof slope angle.

• The canvases are laid according to the described principle to the top of the roof, and a canvas is laid on the ridge, which will be placed on both slopes at once. Since the canvas must be laid overlapped on the sheets fixed below, the ridge part of the roof is waterproofed last.

Very important nuance! Completely covering the ridge with film is only permissible if a super-diffuse membrane is used, with vapor permeability of at least 1000 ÷ 1200 g/m² per day.

When using any other film material, a gap of about 200 mm must be made between the waterproofing sheets in the ridge area - this is necessary to ensure normal ventilation and evaporation of condensate.

• After the membrane is fixed, a counter-lattice, which consists of 30×20 or 40×25 mm slats, is attached to the rafters on top of it. They are attached to the rafters using self-tapping screws.
• Sheathing boards are secured on top of the counter-lattice for installation of the roof covering. The pitch of the lathing depends on the choice of roofing; it can be sparse, frequent or continuous.

For example, if a soft bitumen shingles, then a continuous sheathing of boards or plywood with a thickness of 10–15 mm is installed. In this case, another layer of waterproofing is additionally laid on top of it, and for this, materials such as glassine or TechnoNIKOL are often used. If bitumen-based waterproofing is used, for example, glassine, then the edges of the canvases are laid on a continuous sheathing, which will protect against moisture penetration under the waterproofing.

• For rigid roofing material, depending on the size of its sheets, boards of rare or frequent lathing are attached to the counter-lattice. The most common step size for installing sheathing elements is 350÷400 mm.

• The selected roofing material is laid and secured on top of the sheathing.

Organization of condensed moisture removal

Separately, it is necessary to say about fixing the waterproofing film on the eaves board, since the condensate formed under the roofing and not evaporated into the atmosphere must be discharged into the gutter. If this is not provided for, moisture may get under the eaves board, where fungus can form, which will lead to the destruction of the wood.

This diagram shows the design of a system for draining condensate from under the roof using waterproofing material placed on a metal eaves strip, along which water will flow into the gutter.

If the gutter design has a continuous attachment to the eaves board, then the waterproofing material can be attached directly to it and passed under the metal strip.

Another option for draining condensate is formed by installing a special metal element - a drip line, which is attached to the waterproofing material and discharged under the gutter.

Valley waterproofing

The problem area of ​​the roof can be called the valley - a fracture of the slope, that is, the junction of two planes under a certain, which is carried out under a certain internal corner. The lathing that forms the valley is two or four boards fastened together at the angle where the roof slopes meet.

Before installing the general waterproofing on the sheathing of the roof slopes, a single sheet of waterproofing material is laid on the valley boards from the ridge to cornice strips. It should be evenly distributed on both sides of the valley and securely fixed to them using bitumen, brackets or waterproof construction tape.

Only after the installation of the film on the valley is completed, the waterproofing sheets begin to be fixed to the rafters of the roof slopes from the eaves. Horizontal sheets are laid on top of a vertical hydraulic barrier fixed to the valley, thus, a double layer waterproofing. Only after this a metal valley element is placed in the gutter between the slopes, through which the water will flow.

Installation of vapor barrier films

Vapor-tight waterproofing films can also be used as a vapor barrier, but the principle of their installation is completely different. To understand the difference, the main technological methods for vapor barrier of a roof from the inside will be given.

There are two main ways to install a vapor barrier membrane - from the attic side and from the outside. The first method is more technologically advanced and is used more often, since when performing work, the master sees the entire rafter system, which practically eliminates making mistakes.

Installing a vapor barrier on the roof side

The work is carried out in the following order:

Illustration	Brief description of the operation performed
	This diagram represents the location of all elements of the roofing “pie”.
	If the first option for fixing the vapor barrier is chosen, then you need to start by sheathing the slopes of the rafter system from the attic side. They can be covered with clapboard, plywood or plasterboard. The finishing material is fixed on the rafters, or on the lathing attached to them. Exactly interior decoration will become the basis for the flooring on the outside roof frame vapor barriers and insulation material.
	So, on the outside, a thin layer of insulation is laid on the prepared base; its thickness can be 15÷20 mm. This layer will protect vapor barrier film from punctures and damage by self-tapping screws that secured the interior trim. If there are no sharp elements, then a layer of insulation is not necessary. Next, starting from the cornice, film sheets are laid on all surfaces of the base and rafters. Secure the material using a stapler and staples.
	So that the film fits tightly at the joints of the rafters and internal lining, it is first carefully pressed in the corner with the help of a beam, which will help to straighten it well.
	Then, the film is secured with staples to the rafters. Thus, the first vapor barrier sheet is laid.
	The next step is to lay the second sheet of material, overlapping the bottom one. The size of the overlap, as well as when installing waterproofing, depends on the angle of the roof, and it is quite possible to be guided by the parameters indicated in the table above.
	After laying the sheets, their overlaps are securely sealed together using special waterproof tape.

After installing the film, insulation is laid between the rafters, which is then covered with waterproofing, sheathed with lathing, on top of which the roofing covering is laid.

This approach also has its significant drawback. It lies in the fact that by choosing this installation option, the work will have to be completed in one day, or you can choose a period during which it is guaranteed that it will not rain.

Installing a vapor barrier from the attic side

In the second option, the vapor barrier is secured from inside the attic, and this work is carried out after the installation of roofing materials is completed. In this case, the process takes place in the following order:

• The first step is to lay a waterproofing membrane on the rafters.
• Then, the material is secured to the rafters with counter battens.
• Next, the sheathing boards are fixed to the slats.
• The roofing covering is mounted on them and the ridge is closed.

Now that the rafter system is sealed from the weather, you can safely insulate it from the attic side.

• Mats of insulating material are installed between the rafters; they are pressed against the sheets of waterproofing film fixed outside.
• Then, the insulation is covered with a vapor barrier membrane. It can be mounted horizontally or vertically to the rafters. If the fixation will be done horizontally, then you need to start attaching the film from the bottom. The second canvas is stretched and secured with an overlap of 150÷200 mm over the first, and so the process is repeated until the top.
• After the vapor barrier is secured, the panels are glued together with tape.

• Then, a timber sheathing is installed on top of the film, onto which the attic lining will be secured.

This option is more comfortable to implement than the first one, since half of the work is carried out in safe conditions, under a finished roof.

In conclusion, I would like to remind you once again that you should not indiscriminately purchase any material called waterproofing. It is necessary to approach the choice responsibly, having studied the characteristics in advance and decided which film is more suitable for a particular coating.

Video: a clear example of waterproofing a roof with a vapor-permeable membrane “FAKRO EUROTOP”

When planning your home design, you always want it to be warm and cozy.

To do this, you should follow the instructions when carrying out construction work.

It is also necessary to pay enough attention, in particular, to the competent provision of all types of insulation.

How to choose a vapor barrier for a roof and not make a mistake? First, let's get acquainted with the types of vapor barrier materials.

In residential premises there is always water vapor that circulates inside it. And according to the laws of physics, it rises with warm air. Over time, it will penetrate into the under-roof space, where it will begin to absorb insulation.

With the onset of cold weather, all the moisture that has undergone condensation forms an ice crust. And when spring comes, all the ice melts, and the resulting moisture washes away the internal filling of the roof structure. This will lead to its destruction and loss of basic properties: When the insulation is slightly moistened, heat loss increases significantly.

To avoid these consequences, it is necessary which should be present in any roofing pie. Some people believe that finishing the attic with cladding, which prevents moisture from entering, eliminates Negative consequences. But it is recommended to always use a special coating that is placed between the ceiling and the insulation.

Which vapor barrier to choose for the roof?

There are the following types of vapor barriers for roofs:

• painting;
• pasting.

Painting room

Used more often for high-rise buildings, soft roofs from roofing felt, iron roofing sheets, where insulation is not used. This vapor barrier is well suited for flat roof. The main difficulty in using mixtures of this kind is preparing the surface before application. For this type of insulation, the following compositions are used: How:

• hot bitumen;
• bitumen-kukersol mastic;
• varnish based on chlorinated rubber or polyvinyl chloride.

Pasting (membrane)

This type more popular, especially in individual construction. Materials for this type of insulation are produced in rolls and this provides some advantages:

• simplification of installation;
• ensuring a tight connection when overlapping;
• reduction in the number of seams.

NOTE!

The adhesive insulation is laid in one layer, if the room humidity is below 75%, otherwise add one more extra.

Types of adhesive vapor barrier materials

• Waterproofing. Prevents steam from penetrating into the insulation. Have special perforation, which allows steam to penetrate outside. It is mounted with some clearance from the roof covering, which promotes air circulation between the outer and under-roof space. Has unidirectional vapor permeability, keeps the insulation dry. You can talk about waterproofing materials.
• Anti-condensation. Equipped with special fleecy layer, which is located on their inner surface. It retains moisture and prevents contact with thermal insulation. Moisture quickly disappears due to air circulation in the gap. This type of insulation must be laid with an adsorbent layer to the inside of the room. Attached using a counter-lattice.
• Vapor tight. Provide impenetrable protection inner side roof insulation. Sometimes they have a layer aluminum foil, which is capable of reflecting part of the radiant energy back inside. It is laid with a ventilation gap to the insulation. Provides good protection from moisture, while maintaining heat.
• Membranes. They are modern vapor barrier materials that can prevent moisture from escaping, while allowing air to pass through. When using membranes, ensure air gap often not necessary. This material for roof vapor barrier has gained great popularity these days.

Do you need a vapor barrier for a cold roof?

The special design of such roofs does not require laying two layers: thermal insulation and vapor barrier. This saves money and construction resources. Water vapor that passes through the film ends up between the waterproofing and the corrugated sheet, from where it is removed by an air flow.

Therefore, the main task when installing a cold roof is ensuring good ventilation, which is ensured by creating a gap using a counter-lattice.

Device cold roof

Do you need a vapor barrier under the corrugated roof of a cold roof? No, it’s not necessary, the main thing is to take care of good ventilation.

Vapor barrier for attic roof

The most commonly used materials are glassine, roofing felt and foil insulation. Modern membranes are also quite effective, which have proven themselves in this sector and are excellent for vapor barriers of soft roofs.

First of all, it is necessary to seal and insulate the various structural elements. The vapor barrier is laid on and secured using a method that matches the surface material. You can read about insulating an attic roof.

Fastening to concrete, brick and metal surfaces performed using double-sided adhesive tape, laid with a 10 cm overlap. And it is attached to the tree with nails or staples.

CAREFULLY!

The vapor barrier film must be installed without sagging, with slight interference.

The foil film is installed with a reflective layer inside the room so that thermal energy remained inside the building. A gap is provided between the thermal insulation and vapor barrier parts for ventilation, as well as to create a warm air barrier.

Detailed diagram of the device roofing pie mansard roof

The joints of the film are taped with tape made of a material with a similar coefficient of thermal expansion. It is better to press the junctions of the foil to the wall with strips with sealant applied under them.

Vapor barrier under corrugated sheets or metal tiles

Metal tiles are a thermally conductive coating, so with the onset of cold weather, condensation causes irreparable damage to them. To solve this problem, it is necessary to provide the roof with proper vapor barrier and. Before choosing, you should decide what is more important: price or efficiency? Let's look at which vapor barrier is better for metal roofing:

Cheap option - glassine and polyethylene

Glassine can last a long time, while it has sufficient flexibility and low cost. However, a large mass bad smell heat and installation difficulties make it not the best option.

Polyethylene retains steam well and protects the thermal insulation layer from moisture. It is cheap, but polyethylene is very easy to damage. It is difficult to install it yourself. Due to the significant mass, install the film standard method It’s hard to handle corrugated sheets. Therefore, installation occurs to the inside of the cladding using a stapler. The film is mounted in two layers.

Reinforced film, foil, membranes

In terms of price, it is also an acceptable option. Reinforced film consists of several layers with a reinforcing fabric mesh that adds strength. Light weight and rigidity allow you to install such insulation yourself. Attached with self-adhesive tapes. Significant disadvantage- this is the absence of an anti-condensation layer, which can negatively affect the insulation.

Diagram of a metal tile roof

Which vapor barrier to choose for a roof under metal tiles? One of best options is foil. It has low thermal permeability, which allows you to retain heat in the room, is lightweight and has sufficient strength. The big disadvantage of this material is its tendency to corrosion.

Useful video

We invite you to watch a video about the properties of vapor barriers:

Conclusion

The penetrating ability of steam is sometimes underestimated, which leads to rapid failure of thermal insulation. Therefore, it is necessary to take a responsible approach to the issue of vapor barrier and take into account all the nuances when choosing materials and carrying out work. This will ensure long term services for future construction.

In contact with

Wet insulation loses its thermal insulation properties and comes into contact with rafter system, creates conditions for its rotting. Therefore, the composition of the roofing pie of an attic roof must include waterproofing.

The choice of waterproofing materials and their installation technology depend on the type of roofing.

Waterproofing films

To waterproof an attic roof, you can use two-layer films with an anti-condensation surface. The same ones are used for installing cold roofs.

Advantages:

• high tensile strength;
• possibility of use as a temporary roof for 1-3 months;
• the presence of an anti-condensation layer capable of retaining moisture until conditions are created for its weathering;
• lower price (3 - 4 times less in comparison with membranes).

Main disadvantage- limited vapor permeability, so two ventilation gaps are required:

• the first, between the roof and the film - for the removal and evaporation of condensate;
• the second, between the insulation and the film - to ventilate water vapor from the mineral wool.

Both gaps are made using two counter-lattice bars:

1. The first block of counter-lattice with a cross-section of 4-5 cm is stuffed onto the rafters. It is necessary for the lower ventilation gap, and provides a slight sagging of the film (up to 2 cm), necessary for the condensate to drain to the drip.
2. Waterproofing is attached to this block (with the anti-condensation layer facing up).
3. Through sealing tape fill another slatting with a cross-section of 4-5 cm, to which the roof sheathing is attached.
4. The film under the ridge is laid with a “gap” of 5-10 cm. To prevent the fibers from mineral wool from being blown out, the mats must be covered with fiberglass.

Membranes

Superdiffusion waterproofing membranes laid on top of the insulation without a gap. The structure of the material is similar to a sandwich: a microporous membrane in the middle, reinforcing fabric on both sides.

Weathering of moisture from mineral wool occurs due to high vapor permeability, and only one ventilation circuit for the under-roof space is needed.

Despite the reinforcement, all membranes inferior in tensile strength waterproofing films. And when choosing a specific brand, you need to pay attention to this indicator. It is measured in Newtons, which are “applied” to a sample 50 mm wide.

Membrane name	Strength*, N/50mm	Vapor permeability, Sd	Weight, g/sq.m	Note
DELTA®-VENT N	220/165	0,02	130	The best choice from the German manufacturer DORKEN
Tyvek Soft	165/140	0,02	58	Very light and reliable membrane from DuPont
YUTAVEK 115	260/170	0,02	115	Czech membrane, many good reviews
Izospan AQ proff	330/180	0,03	—	Reinforced membrane with good light fastness
Izospan AM	160/100	0,03	—	Budget membrane, medium strength
Ondutis A120	160/100	0,01	110	Wind and moisture protection for attics with slope angles of at least 35 degrees
Ondutis SA115	160/90	0,02	100	For country house temporary residence
Ondutis SA130	250/120	0,02	140	An excellent choice for a mansard roof made of Ondulin

Installation features

The process of installing the membrane is similar to conventional film, but without the “break” in the ridge area:

1. The membrane is attached to the rafters with a stapler. Laying is done in stripes from bottom to top from the eaves to the ridge.
2. In hip and complex roofs On the slopes along the axis of the valleys and ribs, the membrane is mounted in a separate strip even before laying the main layer of waterproofing.
3. The connecting tape is used to secure the lower edge of the canvas to the drip line, as well as the joints of the canvases with each other. The amount of overlap between adjacent strips must be at least 15 cm.
4. The top strip on the ridge is laid with an overlap over the waterproofing of both slopes.
5. Vertical joints are made with overlap on the rafter legs.
6. After laying the waterproofing, counter battens are stuffed onto the rafters. For Izospan membranes, the recommended lath thickness is 4-5 cm. For Ondutis membranes, the thickness of the bar should be at least 3 cm for profiled roofing and 5 cm for non-profiled roofing. A sealing tape is laid between the rail and the membrane.
7. A roofing sheathing is attached on top of the beam.

Waterproofing an attic roof made of bitumen tiles

Bituminous shingles differ from other types of pitched roofing both in terms of installation technology and waterproofing.

There are two waterproofing layers:

• between solid decking and asphalt shingles.
• Superdiffusion membrane on top of insulation.

An underlayment covering the entire roof area is only needed when the slope angle is up to 18° (minimum 12°). On a roof with a slope of 18° (1:3) underlay carpet necessary only on valleys, ribs, cornice and front overhangs, at junctions (around skylights, chimneys, ventilation pipes).

Waterproofing film or membrane: which is better to choose?

In an attic roof, the main heat loss occurs due to its “blowing out” from the insulation. This will happen if you use conventional waterproofing films and two ventilation gaps.

The membrane laid on top of the insulation serves as a wind barrier and reduces heat loss by preventing it from “blowing” out of the insulation. The material is more technologically advanced, but costs more than conventional films.