The best waterproofing film for attic roofing. How to choose a vapor barrier for an attic roof

Wet insulation loses its thermal insulation properties and, coming into contact with the rafter system, creates conditions for its rotting. Therefore, in the composition roofing pie mansard roof Waterproofing is required.

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;
• more low price(3 - 4 times less compared to 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. Another strip with a cross-section of 4-5 cm is stuffed through the sealing tape, 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 are 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.

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. For hip and complex roofs, on the slopes along the axis of the valleys and ribs, the membrane is installed in a separate strip 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 an overlap of rafter legs Oh.
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 roofing pitched roof both 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.

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 internal filling roofing 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 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 no insulation is 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;
• security hermetic connection with overlap;
• 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 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. They provide impenetrable protection to the inside of the 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.

Cold roof installation

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 carry out sealing and insulation various elements designs. 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 is carried out 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 roofing pie of the attic 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 its significant mass, it is difficult to install the film to the corrugated sheet using the standard method. 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. A significant drawback is the lack 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

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 people living in the house or favorable conditions for items placed inside. Waterproofing film for roofing, selection and installation - such aspects always raise many questions, since creating a reliable barrier against 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 it can be very difficult to immediately understand the features of a particular film. 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 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 general protection buildings from moisture penetration. Waterproofing the rafter system helps to avoid frequent repairs and extends the life of the building as a whole.

Of particular importance is protective film, if the under-roof space is insulated with one of the types of thermal insulation materials that are capable of absorbing 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 simple mistakes 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 a pitched 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 gable 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 attic space).

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 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 attention to this factor. Special attention.

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 sufficiently represented a 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 that 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 is winter period protects the insulation from atmospheric humidity, and in summer - from overheating, reflecting ultraviolet 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 a 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 a 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 metal coatings is used for the roof - 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 purchased waterproofing film 1500 m wide, then its installation on a 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 staplers.
• 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 solid sheet of waterproofing material is laid on the valley boards from the ridge to the eaves 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 water barrier fixed to the valley, so a double layer of waterproofing is necessarily formed here. 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. Finishing material fixed on the rafters, or on the sheathing attached to them. It is the interior decoration that will become the basis for the exterior flooring. roof frame vapor barrier 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.
	In order for the film to fit snugly at the joints of the rafters and the internal cladding, it is first carefully pressed in the corner using 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 rafter system closed from atmospheric influences, you can safely insulate it from the attic.

• 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”

Insulation and vapor barrier on attic floor. Competent finishing work is the key to the durability of the building, as well as a comfortable microclimate.

Typically, the attic includes the following structural fragments:

• interior decoration of the premises (basis for finishing);
• vapor barrier;
• thermal insulation;
• waterproofing (otherwise – wind and moisture protection);
• sheathing with ventilation gap;
• roof.

A vapor barrier layer is needed to compensate for the temperature difference - inside and outside the house. At a global level, vapor barrier, like waterproofing, which will be discussed below, is necessary to protect the roof of a house. According to building codes, between the vapor barrier layer and the interior finishing layer it is worth making a small air gap so that moisture does not stagnate. Suitable materials- glassine, roofing felt, membrane and, of course, the usual polyethylene construction film.

If the vapor barrier serves as a barrier to the formation of condensation on the insulation with inside roof structure, then waterproofing protects it from the outside. Leaks in roofing materials are always possible, and the insulation can be seriously damaged. There are enough material options - from simple thick plastic film to mastic. Both polypropylene laminated film and diffusion membrane have proven themselves well. The latter perfectly retains moisture, while preventing condensation from accumulating.

What materials are used for attic insulation?

Insulation for the attic floor must not only be chosen wisely, but also its installation must be trusted to professionals. Blowing out heated air is the main problem in the attic. To keep your home warm, you should choose modern thermal insulation materials, such as mineral and glass wool in roll or slab form.

Glass wool in any form is the most a budget option with its pros and cons.

• it contains no harmful components or substances
• does not burn

• Fine dust that, when it comes into contact with the skin, scratches it and causes itching
• It is inconvenient to use when insulating walls that may be located at an angle, since over time the insulation peels off and does not fit tightly to the walls.

Mineral fiber wool is better according to some criteria. The presence of natural components in the composition balances the material’s parameters. Mineral fiber wool is very light and safe for health. Excellent for insulating attic walls or insulating the attic roof with mineral wool in a private house, as well as for insulating the house from noise.

Everyone is free to choose the top roofing covering based on the characteristics of the project, their preferences and the construction budget. At construction work It is important to take into account one technological subtlety - you should not forget the ventilated gap. It represents the free space between the waterproofing layer and the roofing material itself, and its size depends on the type of roof and type of coating.

Insulation and vapor barrier on the attic floor should be approached with maximum attention, because part of the attic roof serves not only as the roof of the house, but also as the ceiling of the living space. It is also important not to miss the issue of insulation attic walls and gender. In a good way, protecting the floor in the attic is a matter of thermal insulation of the house as a whole, and the walls are often equipped during the insulation of the roof.

Attic insulation technology

The roof and floor first need to be insulated in the attic, but don’t forget about the walls. It is possible to do without insulating walls only if they are formed by roof slopes, that is, the roof reaches the floor. In all other cases, the walls are insulated according to the same scheme as the ceiling.

In the video below you can clearly see step-by-step technology attic insulation mineral wool. In addition to mineral wool, penoplex can be used to insulate the attic from the inside.

When constructing an insulated attic roof, a vapor barrier must be used. The absence of this layer in the roofing pie leads to wetting of the insulation and premature destruction of the rafter system.

Vapor barrier for attic roof protects insulation and load-bearing materials wooden structures roofs from saturation with moist vapors that appear as a result of human activity.

This reduces the risk of fungus and mold appearing in the under-roof space.

Do not confuse vapor barriers with superdiffusion membranes. The latter are laid on top of the insulation and play the role of waterproofing, but at the same time retain the ability to “breathe” and remove moisture from the surface of the insulation.

Materials for roof vapor barrier are represented by several types of films:

Single layer films made of polyethylene or polypropylene. They are characterized by low strength; if handled carelessly, the film can easily be torn.

Which vapor barrier to choose for the attic?

• Multilayer films— have higher strength and service life, and can be additionally reinforced with a reinforcing layer.

  Reflective films with a reflective layer of foil - allows you to retain heat in the room and will become great solution when installing a roof over a sauna, swimming pool or bathroom.

Read also: how to properly insulate the roof of a house.

1. If financial capabilities allow, choose Delta Reflex or AirGuard Reflective films.
   Delta DAWI GP is a little simpler and cheaper.
2. AirGuard Sd5 - suitable for houses with non-permanent residence.

   Has limited vapor permeability to remove residual moisture from the room.

3. Jutafol are Czech films from the Juta company.

   Lots of good reviews from builders, excellent choice in terms of price-quality ratio.

4. Ondutis and Izospan are an economical option.

Rules for installing vapor barrier film

The vapor barrier film is laid on top of the insulation from the attic side and fixed using a construction stapler.

The joints of the canvases are taped with mounting tape to ensure tightness.

When working with the material, you should consider the following tips:

The sheets can be laid in any direction if there is a rough insulation file. When installing directly on the rafters, it is better to place the sheets horizontally.

The minimum overlap of one canvas over another should be 10 cm.

Joints and junction points must be carefully taped.

When working with window openings It is worth providing for a deformation reserve (fold). Near windows, it is important to pay special attention to sealing the junction points and protecting the material from sunlight.

After fixing the vapor barrier, perform wooden sheathing 25 mm slats.

It is needed for attaching the rough sheathing and creating a ventilation gap. When finishing the ceiling and walls of the attic with plasterboard, a special metal profile is used instead of bars.

Competent and high-quality performance of attic vapor barrier work will extend the life of the roof and save the home owner from costly repairs.

mvnvdanvamnbaa

Benefits of this option
What a cold roof
Installation steps
Roof structure for metals, including waterproofing
Tools and accessories for installing a cold attic

Currently, specialists use all types of roof structures when building a private house, but most often they build a cold roof.

This perfect option when the attic is not intended for use as a residential building. Below we will talk about how to properly install a cold metal roof.

Which steam bar to choose for the attic?

Benefits of this option

The design of such a roof is quite simple - you need to build a building, apply a layer of waterproofing, a box and control panel, and a roof. The main thing when installing a cold roof is to provide air clearance to allow condensed moisture to be removed. This is necessary to ensure that Basic structure and roofing material were not exposed to moisture.

In itself, the installation of such a roof should not be accompanied by complications during the work; it is only necessary to properly fix the roofing coverings so as not to leave precipitation through the connection in the underground space. Before you create a mug on the roof of a cool attic, you need to complete a full list of calculations, determine the slope of the skateboard, rotate the basket and choose the appropriate method of fastening the sheet metal.

What a cold roof

Cold roofing technology for metal roofs takes care of the initial installation of the roofing system, after which a membrane and polyethylene film will be placed on it to provide waterproofing.

They fill the control box, assemble it and lay down the metal roofing.

The characteristic of this type of roof is that there is no need to install insulation - all that is necessary is to provide vents under the ridge and on the slopes to remove moisture. Make sure that all preliminary calculations are accurately determined.

The roof installation has the following characteristics:

1. If you plan to build a hot roof over time, the protection of the moisture barrier membrane must be careful.

   If you plan to build an attic, a PVC membrane must be present.

2. If the roof does not need to be insulated in the future, it will be necessary to install micro-perforated flashing, which is used for cold roofs. It is impossible to install insulation with such a film, and if you continue to insulate you will need to buy a new membrane.

   Otherwise, the roof will not be protected from moisture in the future, the heaters will not have enough time to dry, and the roofing material will turn brown over time.

Installation steps

When installing the membrane to protect against moisture, it should be noted that it must remain a small roller of at least 20 mm. In this way, condensation moisture can be achieved, thereby protecting the rafters and other roof elements from decay.

So that the water does not evaporate on time, without stagnating and thereby creating an unfavorable environment, care should be taken to include a fan steam in the design, which is installed between the repellents to protect the film and the ridge roof.

Such a clearance will allow simple circulation of air flow in the room under the roof and removal of all condensation. The built-in membrane must not be damaged or otherwise damaged. The best way to fix this is to use a structural stapler.

The membrane layers are laid with a slight overlap, and the edges are laid using adhesive tape.

The design of the cold attic roof is such that it can be used in regions with any climatic characteristics. Many people believe that this type of roof does not apply to the northern regions, although in fact this is not the case. Cold attic rooms are often installed in such regions.

The attic is insulated and the cold roof does not affect internal microclimate upper floors. The attic cannot be used because installing an insulating layer between the top floor and the space under the roof eliminates all the nuances that affect heat loss.

When installing a cold metal roof, measures must be taken to insulate vents, chimneys, and attic outlets.

This way, you won't have to worry about condensation buildup, icing, heat loss or rain and melting water.

A cold roof can be covered almost entirely roofing tiles, and due to the ease of installation, a metal roof is used much more often.

Some other types of roofing materials, especially soft roofs, also work well in this situation, but they require a lot of time and money to install.

Roof structure for metals, including waterproofing

To block cold attic With metal roofing, the most convenient and easiest way to install a roof.

In this case, the roofing cake consists of a waterproofing material that is attached to the raft frame, slats and roofing coverings(metal tiles). In fact, the application of such a coating occurs very quickly. Insulating film they are fixed with staples or nails, and then additionally pressed with thread, self-tapping screws are screwed in. The installation of rail guides is carried out taking into account the dimensions of the metal plate.

The cabinet plate is made from 25mm to 100mm, and sometimes plywood or particle board is used if hard floors are needed.

The installation of film or membrane for attic waterproofing is loose, with some stretch.

However, it makes sense to ensure that the integrity of the coating is not interrupted, that is, any holes or cracks are excluded. As a rule, the film can be stretched by 15-25 mm. In this way, ventilation of the inside of the waterproofing membrane is achieved, condensed moisture is removed at the handle and further into the drain. Ignoring this simple rule will ultimately lead to premature deformation of the roof frame and the entire roof.

The thing about a metal tile roof is that cold roof film cannot reduce the noise that occurs when the metal is exposed to heavy rainfall.

Therefore, living spaces with such a coating provide a layer of thermal insulation that absorbs strong noise. Without this layer, as a rule, only rooms for self-contained attics are equipped.

Thus, a cold roof will include the following layers:

• A cold roof vapor barrier is installed inside, which only releases moisture and prevents it from entering the living room.
• Then install the raft frame for the roof.
• The next layer is a waterproofing material.

  The film is laid with a recess to drain condensate.

• A control grille is then attached, which compresses the waterproofing, secures it and provides ventilation holes.
• The post is then filled to repair the roof.

  It is made of 50 x 50 mm blades and laid along ramps divided into 35-45 cm. Depending on the type and extent of the roof beam, the pitch and thickness of the panel can be changed.

• The rear floors are made of metal.

Tools and accessories for installing a cold attic

It is worth noting that you will not need overly complex professional Building tools for laying metal tiles.

You can use the basic set that every housewife has in her home.

In addition to the frame frame, frames, slats and counterflow flasks require membrane or foil insulation for steam and waterproofing, as well as a sufficient number of metal tile sheets purchased from the same series.

All elements are secured using clamps, self-tapping screws, galvanized nails and even anchor bolts.

However, it should be remembered that they must be of high quality so that the roof does not deteriorate prematurely.

Concerning roof roof, then the evaluation lists are glued, the required roof valley (internal and external), wreaths, wind and snow stations and watercourses.

The main difference between a cold roof and a warm roof is the presence of thermal insulation material located between the water layer and the vapor barrier.

The main functions of the attic vapor barrier layer
Types of vapor barrier materials - which one is better to choose
Polyethylene films
Polypropylene films
Vapor barrier reflective membranes
Rules for installing vapor barriers

Thermal insulation of the attic is a very important process, since it leaves through the roof and walls a large number of heat.

To reduce the loss of thermal resources, it is necessary to carefully consider the structure of the roofing pie and ensure the effective functioning of each layer.

An important role in this process is played by the attic vapor barrier, since this layer does not allow moisture to penetrate into the insulation and to wooden elements rafter frame, thereby extending their service life without loss performance characteristics.

The main functions of the attic vapor barrier layer

To answer the question of which vapor barrier to choose for the attic, you need to know its purpose.

When warm and cold air flows combine, steam and condensate always form, the accumulation of which certainly leads to a decrease in the performance characteristics of any, even the most reliable building material.

Wood rotting reduces the strength of the entire structure, which becomes the reason for repair or complete replacement of the main parts of the structure. In addition, high humidity promotes the formation of mold and fungi, which release toxic substances.

As a result, a person may experience malaise and headaches, and even allergies.

The joint work of insulation and vapor barrier not only prevents the penetration of steam, but also retains maximum heat in the attic room.

Types of vapor barrier materials - which one is better to choose

Can be used as a vapor barrier layer various materials, including roofing felt, glassine and various films.

The most popular today are polyethylene and polypropylene films, as well as vapor barrier membranes. To understand which vapor barrier is best for the attic, you should get acquainted with the basic materials.

Polyethylene films

This material is laid during the installation of the roof; a prerequisite for use is the creation of gaps for ventilation.

This will prevent the formation of condensation, since polyethylene is not capable of allowing air to pass through. Laying with the rough side facing out promotes the evaporation of steam particles.

Polyethylene film can be used for vapor barrier and waterproofing thanks to universal characteristics. Reinforcement with a special metal mesh helps increase the strength of the material.

Polypropylene films

High durability and strength are the main characteristics of this material, but at the same time it has one significant drawback.

How to choose a vapor barrier for an attic roof

The upper side of the reinforced film is covered with drops of condensation. If the choice of vapor barrier for the attic is made in favor of this material, then laying an additional layer of viscose or cellulose, which absorbs fumes, will help solve the problem.

Vapor barrier reflective membranes

This insulation does not require ventilation gaps, since the structure of the material is capable of allowing air to pass through and retain moisture.

In addition, the membrane is characterized by high quality and reliability. The attic vapor barrier should be installed on top of the insulation.

In addition, a vapor barrier is installed using isospan or penoplex.

These are high quality materials, characterized by a low thermal conductivity coefficient, excellent waterproofing and vapor blocking properties. One of the advantages of their use is operation at high temperatures.

Rules for installing vapor barriers

A reflective vapor barrier for the attic, installed in accordance with all the rules, can protect the insulation from moisture penetration and preserve its performance qualities.

First, you must first seal and insulate the main structural elements and all protruding parts of the structure.

Secondly, the method of fastening vapor barrier material depends on the type of surface. The material is attached to concrete, bricks or blocks using double-sided adhesive tape. On wooden surfaces The vapor barrier is fixed using nails or a construction stapler.

Thirdly, when using foil vapor barrier for the attic, the reflective layer must be turned inward.

Fourthly, for maximum efficiency vapor barrier should be used without damage. And during the installation process, the material should be tensioned to avoid sagging.