Vapor barrier for roof: the types and effectiveness of the use of

Heat retention - is not only a component of the economy. First of all, it is the health and comfort. Excess moisture in conjunction with the cold air leads to the formation of damp and mildew. Be in a room where there was a fungus, not only uncomfortable but also unsafe. In addition, this leads to the inevitable destruction of building structures, which are under constant exposure to moisture. Modern reliable vapor barrier for roof will help to avoid the above problems.

What is a vapor barrier

dryness level of comfort, keeping warm in the room depends on the condition of the roof. It is a barrier between the cold external environment and internal heat of the building. Use of heaters in the absence of a waterproofing roof ineffective. Waterproofing prevents penetration of steam from the housing in insulation layers.

For a long time as conventional polyethylene vapor barrier film used in the device of roofs. But this material is mechanically vulnerable. In addition, it is characterized by relatively high levels of moisture permeability. Modern roofing vapor barrier film has a water vapor permeability of 0.4 g / m² and a conventional polyethylene - 13-20 g / m². It applies to all types of roofs: flat, pitched, when the device attic floor. Especially important is a reliable steam, cold attic ceiling.

Vapor barrier is a component of "roofing pie", which also includes a waterproofing and insulation. If the "pie" laid correctly and with quality materials, the basic functions of the vapor barrier can be considered:

• preservation microclimate, ensuring ventilation, maintenance of optimal temperature and humidity levels in rooms of the building;
• protecting roof structures from penetration of moisture from the outside and the inside steam, condensation prevention, damage, mold, mildew;
• reduction of heat loss in cold weather, thereby saving on the cost coolants;
• increasing the fire resistance of roof structures;

• reduction in the cost to repair the roof and building.

The lack of implementation of at least one of the above functions speaks about the poor quality of the film or of the mistakes made during its installation.

Useful advice! Before acquiring vapor barrier material necessary (in the absence of knowledge) to consult with a skilled roofer. Wrong choice can result in damage to the thermal insulation material with steam.

Types of vapor barriers and their features

Modern insulation film, actively displacing simple polyethylene, roofing felt, asphalt, and a wide assortment assignment. The most common, affordable and a method for the following types of installation:

• Standard vapor barrier film. It does not form condensation on the roof and a heater;
• foil vapor barrier. In contrast to the standard reflective layer has a function and provides increased Vapor proof barrier, and reflects and returns some of the heat in the room;

• membrane film. It has the effect of isolation and limited water vapor permeability, which allows you to control the removal of excess moisture from the room.

Insulation film may be made of polyethylene or polypropylene. Polyethylene - the material fragile, because plastic products are reinforced with a special cloth or wire mesh. Polypropylene films are woven material, laminated on both sides of a very thin polypropylene. This type of product is durable, resistant to ultraviolet light.

There are options when polypropylene film is applied to the antioxidant layer, which absorbs and retains moisture, and after termination Incoming steam layer dries by ventilation. Apparatus vapor barrier of this type allows to stack it in only one way: gritty antioxidant layer located underneath, smooth surface - on top.

Film laminated on one side foiled layer have the highest qualities and vapor resistance They are the most suitable type of vapor barrier for ceiling rooms with high humidity (saunas, swimming pools and so on. d.).

Variety of membrane films

A special type parozaschity are podkrovel'nye membrane. It is durable, resistant to changes in temperature material. It is different low water vapor permeability, but it is effective in the construction of certain types of roofs. It characterized by a more complex structure than a conventional film. Membrane pores resemble microscopic funnel. Due to this property it does not let the steam from the outside, but perfectly removes moisture from the inside. Currently available are several types of underlay membranes:

1. Perforated membrane. This fiber reinforced film or composite fabric having stab openings. It is used for arranging cold slanting roof. It can not be used for parozaschity insulation. In frosty weather the steam may settle on the inner surface of the membrane.
2. The porous membrane. It has a plurality of interfiber pores for passing therebetween the water vapor. Water vapor permeability material may be different, it depends on the pore sizes and the degree of hydrophilicity of their walls. It is not recommended to use this type of parozaschity in extremely dusty conditions. The dry and windy weather dust through the gaps may settle on the diaphragm and to close pores.
3. Superdiffusion three-layer membrane. They are made of several layers. They have no openings into which can penetrate dust or moisture that is a significant advantage. The membranes do not lose their high vapor permeability in a dusty environment. Also worth noting is their excellent ability windproof.
4. Two-layer film membrane. A cheaper version of the multi-layer product. The absence of one of the protective layers significantly affects the reliability.

Vapor sealing materials must be flexible, durable and easy to use. When attaching the dowels, screws, staples, nails need, so they are not torn, but it is a close fit to the mount.

Useful advice! When choosing a vapor barrier material must pay special attention to quality, since this bottom layer of the roof structure and its repair almost impossible.

Basics correct choice

At arrangement of the roof is not only important to know how to stack a vapor barrier, but also as to determine the necessary material. Consider when choosing a need, above all, the type of roofing material.

If the roof deck will be produced from the materials of low thermal conductivity: slate, tiles, Ondulin, onduvilly - to use vapor barrier membrane diffusion.

Roofs of metal, corrugated and standing seam roof (Compound sheets by a bead) is recommended to protect using a vapor-proof film with anti-condensation layer.

The following parameters must be considered when choosing a vapor barrier materials:

• water vapor permeability;
• longevity of operation;
• mounting features;
• cost.

water vapor permeability level is measured in g / m² per day. The lower the permeability, the more reliably protected from getting wet insulation, decoration, design elements of the roof. To some extent, the film must provide ventilation, otherwise will create a greenhouse effect to the room. Anti-condensation and polypropylene films "breathing" diffusion membranes provide optimum parozaschitu.

Durability vapor barrier materials due to a number of qualities:

• tensile strength and tear;
• resistance to high temperatures;

• non-susceptibility to the effects of ultraviolet radiation.

Budget polyethylene film may be torn during installation and already disintegrate the temperature changes. Durability differ vapor barrier membrane of non-woven synthetic fibers with a protective layer. They are resistant to mechanical damage and exposure to heat.

installation of the new features need to know before purchasing a film, so how to calculate the amount you can only if you know the amount of laps. Also buying related material depends on the method of installation. If the adhesion of vapor barrier material to the mounting scotch low, then it is inevitable eventually lead to a breach of integrity vapor barrier. Therefore, it is necessary to buy another type of adhesive tape.

Price for a vapor barrier of the roof depends on its quality. Budget options are short-lived. Must be able to correctly calculate the cost of the material. Low price per roll may not mean the best value, and be the result of a small square footage. Only a comparison of prices per 1 m² of various types of vapor barrier will help to make the right choice.

Useful advice! film quality should be as roofing material. If the material is designed for continuous operation, and a vapor barrier validity smaller when replacing the need to disassemble the entire "roof pie".

The sequence of placing a vapor barrier: the ground rules

Vapor barrier is of two types: roll and sheet.

Mounting roll stacking is as follows:

• material is rolled;
• metered desired length and have their webs with a plate (100-200 mm) to adjacent moieties;
• fixed clamps or wooden rods;
• overlaps the joints and fastened to a vapor barrier tape (or other tape).

Sheet installation requires the creation of a wooden batten or frame of the profile, which will be laid waterproofing. Can be secured with screws or staples (or material).

When installing "roofing pie" question: "Which side of the vapor barrier stack" - appears among the first. Identical on both sides of the complexities of the film during installation does not cause: a vapor barrier or positive side - effect is the same. Film having a bilayer structure in which one side is smooth and the second rough (for retention condensate) is placed smooth side outwards (adjacent to the insulant) and rough - inside premises.

Related article:

Waterproofing roll materials foundation

Execution waterproofing work on the foundation of rolled materials of various types: a detailed instruction.

Which side of the stack to a heater foil vapor barrier, it is also easy to identify. Since this kind of a vapor barrier is not only for blocking moisture vapor but also for retention of heat, the reflecting side (foil) must be directed inwards to the room.

Membrane vapor barrier can be two-way, and then for its efficiency does not matter which side of the vapor barrier to a heater of this type is located. If the vapor barrier membrane unilateral manufacturer necessarily mean the wrong side.

The basic rules of a vapor barrier installation:

• purifying and drying the coating;
• vapor barrier film should be mounted without sagging, with a slight tension;
• necessary for the proper functioning of the ventilation system;
• obligatory sealing of joints.

Useful advice! When purchasing waterproofing should read the instructions (summary). Sometimes it takes not one, but two air blowing.

How to style your vapor barrier for roof

Mounting of roof vapor barrier - a process whose complexity depends on the type of roof.

The intricate truss structure and accordingly, the shape of the roof, the more costly and complicated task becomes the insulation quality. Installation of Hydro and roofing should be done from the inside.

stacking webs can be performed vertically and horizontally. If you select a horizontal way is to start is necessary to mount on top. Each successive web is laid on the previous one with overlap of at least 10 cm. The seams are sealed with adhesive tape. Sided tape can be used, it is placed on top. Double-sided tape is put inside.

If the installation of a vapor barrier for the roof carried out along the rafters, t. E. vertically, the overlap should be done paintings on wooden rafters. To a wooden structural elements vapor barrier material fastened with galvanized nails or staples. Designated sizing joints desirable to enhance the clamping bars, which are especially important to use on roofs with a slope up to 30 degrees and at a low density insulation.

Useful advice! Used wooden planks and bars should be treated with antiseptic. This will significantly extend the life of a full-fledged operation.

If the construction has roof windows, hatches or other passages through the roof, it is necessary at the periphery thereof paste butyl rubber self-adhesive tape, which excludes the passage of water vapor and firmly seal the cut-out space in the insulation film, even if they are adjacent to the not entirely smooth surface. In this type of tape high water-repellent properties and good resistance to thermal shocks. In addition, it easily eliminates irregularities.

When tested through the roof ventilating pipe, the film should wrap and the wrap tightly around them firmly securing sided adhesive tape.

Mistakes made in the process of laying a vapor barrier

In the absence of experience and professional advice when installing a vapor barrier may be a number of errors, which subsequently significantly affect the efficiency of vapor barrier performance. The most common of them:

• loose abutment film to purlins, beams, roof valley and spinal ridge beams;

• not knowing which way to put a vapor barrier to a heater;
• Use for sealing a narrow adhesive tapes (50 mm);
• when sealing the openings left no deformation margin of the film (20-30 mm);
• polyethylene product around skylights not locked from the inside, so that after some time it is destroyed under the action of ultraviolet radiation and low temperatures;
• film surrounds rafters. The gap between the rafters, and the moisture will penetrate parozaschitoy;
• at the junction of the film to a significantly uneven surfaces do not use special glue. Building scotch tape, butyl, and other types of adhesive tapes complete integrity in such cases do not provide.

Useful advice!When installing a vapor barrier should not be neglected, even seemingly minor rule or disrupt the installation sequence. A good result will be achieved only if all the requirements.

Vapor barrier for ceiling hardwood floor

Wood - organic material, because of evaporation passes. But also for her excessive moisturizing steam is undesirable, since under its influence expanded tree can rot. To the ceiling, which is a cold attic, maintained in good condition, you should arrange a proper vapor barrier. It is important to observe the sequence of installation. The first component is positioned, having a minimum vapor barrier. It should be zero or close to zero. The following layers - a permeability than the previous day.

From steam room should look like this:

• steam. A polyethylene or polypropylene film, a diffusion membrane. Stacked on top of the ceiling;
• insulation. Round, the filling material or tile. Fills the void between the joists;
• waterproofing. A layer of a diffusion membrane or perforated polyethylene. Fit only for use of the attic.

If the attic is not planned to use, the waterproofing layer is transferred under the ramps, where it performs the protection of the entire roof.

Laying vapor barrier material such as wooden beams made with rounding of each beam. Stripes are mounted perpendicular to the joists. The material in this case is not stretched, slight sagging are compulsory.

In panel wooden overlapping turns each compartment. The material cut out according to the size and height of the shield walls.

Useful advice! should not rewind the roll vapor barrier material, so as not to confuse the direction that should be in contact with the ceiling (it is specified by the manufacturer).

Vapor barrier for bath

Bath - room, which requires a high temperature and characterized by a high level of humidity. Vapor barrier of the structure used to store the heater, as well as to protect wooden structures from moisture. When choosing paroizoliruyuschih materials must take into account that different on the premises purpose it is advisable to use a different isolation:

• optimal variant for steam - steam foil reflecting heat and creating additional effect thermos;
• paroizolirovat shower can be a polyethylene or polypropylene film;

• in the dressing room and rest room would be appropriate membrane vapor barrier, which will provide the required ventilation.

Recognized as one of modern materials is paroizoliruyuschih "Izospan B". He has a fairly broad-based. The instructions on the use of a vapor barrier "Izospan B" indicates that it can be used for:

• roofing;
• sex;
• walls, both outside and inside;
• laminate flooring and parquet.

Duplex structure of this material allows it to actively use a vapor barrier in baths smokers. How to lay a vapor barrier and a vapor barrier side mount "Izospan B", it suggests the existence of different structures sides: rough surface intended to absorb vapor, therefore it should be aimed inwardly premises.

Do I need a vapor barrier for insulation of mineral wool

Mineral wool insulation - effective type of thermal insulation, which is actively used in modern construction. But he has a quite significant drawback: when wet mineral wool collapses and loses its insulating properties. That is why the use of a vapor barrier film, along with the heater, it is imperative. It will create a barrier that will protect the layer of insulation from the effects of steam and will provide an opportunity to keep warm room.

Which side to put a vapor barrier when using mineral wool insulation?

If you use double-sided film with moisture-absorbing layer, it must be sent to the room, where a couple of streams rise. The smooth side is adjacent to the heater. When using a material with folgizirovannoy surface, the aluminide coating would be a barrier to penetration of moisture into the insulating material. Consequently, on the premises and it shall be directed precisely this surface.

Useful advice! If mineral wool is used for thermal insulation of premises with high humidity, it safer to use with a vapor barrier layer folgizirovannym, since it has the lowest level of water vapor permeability.

Prices and manufacturers

Technonikol Company - a leading manufacturer of vapor retarding materials in Russia and CIS. Production is issued on the basis of the polymer. The following types of vapor barrier Technonikol:

• for pitched roofs (partially has the ability to pass steam);
• for flat roofs (has high strength, elasticity);
• reinforced (enhanced high-strength three-layer film);
• universal (applicable to all types of roofs).

Price vapor barrier Technonikol for m²v average of 20 rubles. This low price level with good quality.

Vapor barrier Yutafol– European products manufacturer, which is varied to meet different goals when installing a vapor barrier. For the convenience of the buyer to easily distinguish between the material, not to be confused waterproofing, wind insulation and vapor barrier, they have Yutakon names Yutavek and Yutafol (respectively). In addition to the standard types of products, this Czech company produces film Yutafol SPECIAL H110 with self-extinguishing agent, which reduces to a minimum level of flammability. The price of the film for 1 m² - 17 rubles. Cheaper products due to ease of packaging - a good solution company.

Vapor barrier Axton - products of the French company Leroy Merlin. It has three types: B, C and D. In Axton - plastic film, a budget option. Will last a considerable time by avoiding mechanical damage and the right to fix, using not a stapler, and special nails with wide hats. This material is used only for internal installation.

Axton C - Polypropylene products, more durable, versatile. It has a variety of indicators of permeability. This double-layer material, it is recommended for insulated and non-insulated roof types with a variety of designs. Axton D looks like a tent. It is used for water and vapor barrier. It characterized by high durability, ease of installation. Products of this company are distinguished with a high level of environmental performance.

Vapor material Tyvek are produced at a factory in Luxembourg. Underlying - high quality polyethylene, non-woven structure. The main difference between products - environmentally friendly and innovative technology created by "breathing" membrane with a controlled water vapor permeability. Price vapor barrier Tyvek 7-10 percent higher than the price of domestic counterparts.

Price ceiling vapor barrier is most dependent on the quality of the material, its density and the producer. That is why branded products of foreign companies has a higher cost.

Vapor barrier for roof: modern solution to moisture protection

Roof - building element that can withstand constant double burden. From the outside it is exposed to atmospheric conditions: rain, sunlight, low temperatures and wind. From inside the internal impact it experiences temperature and humidity. In such circumstances, overemphasized the need for proper vapor barrier devices, the lack of which can lead to the destruction of the roof and then the building itself, it is simply impossible.

Modern technology has allowed the film to create polymers that can provide the necessary level of vapor barrier. A wide choice of materials allows to use it in accordance with the conditions and purpose. Having carefully considered how to put a vapor barrier, fulfilling all the technical requirements, you can create a healthy indoor microclimate and provide the structure as a whole for years of existence without major repairs, maintaining the aesthetic appearance view.

The price of a vapor barrier for roofing per m² no reason to think high, making the material available to any developer.

Implement reasonable and rational choice materials, the correct installation of vapor barriers do - the desire of every homeowner. The content of the article is intended to help install vapor barrier on their own. But even if such a solution is unacceptable, you must be aware, in order to properly assess their costs and quality of employed professionals.