Waterproofing films or diffusion membranes , are used in the construction of pitched roofs to protect insulation and other internal roof structures (rafters, battens, fasteners, etc.) from condensation that can form on the inner surface of the roof covering. Also, waterproofing films protect the roof space from moisture that gets in due to heavy rain with wind or snow in winter.
What is the function of a roof membrane?
The main task of a roofing membrane is to protect the attic and warm up from possible roof leaks. In addition, the diaphragm depletes the water vapor that forms in the insulation of the attic due to temperature fluctuations during the day. When the sun goes down, the temperature drops to a few degrees after dark. Fluctuations in temperature over a 24-hour period lead to a condensation effect, that is, to convert water wandering through the membrane towards the sheet of water vapor that settles on the underside of the sheet metal or trapezoidal sheet.
Modern roofing materials, to a greater extent, have a service life of 30 to 100 years, and it would be unreasonable to use under-roofing membranes that serve only 5 years. Replacing the roofing material often leads to the replacement of the roofing itself, which is expensive, unnecessary and unjustified.
Therefore, it makes sense to pay attention to the large selection of roofing films offered by various manufacturers today.
The water then drips by gravity onto the roof membrane, which is a few centimeters below the sheet metal. Condensed water flows freely through the indestructible top layer of the membrane to the gutter. In addition, during heavy rainfall, each roof is exposed to water flooding, which gets under the sheet through various leaks in the roof structure. Thanks to the diaphragm, the water passing under the sheet is effectively drained in the gutter.
Why is a roofing membrane the most important roofing element?
In conclusion, the task of the roof membrane is to release water vapor from the bottom and on the side of the sheet to protect the attic from moisture. The critical task of a functioning roofing membrane is invisible to the user and uncontrollable. The diaphragm is installed once on the rafters, that is, under the roofing sheet, but over the insulation in the attic, and therefore the function of this element is invisible to the user. The effectiveness of the roof diaphragm, its high quality and delicate method of fastening ensure that the client is not harmed by moisture.
How to properly mount the under-roofing film in the roof structure?
Diffusion membrane... It is a type of single layer films or multilayer membranes, which are able to pass through the vapor of water vapor, while larger and heavier water molecules they do not pass back. If you bring such a membrane to your lips, and slowly exhale through it, it will slowly but let air through itself without creating the typical sound.
In the first case, the damaged roof membrane does not protect against falling water from the underside of the roof sheet, which causes wetting of the attic insulation. Second - The cheap, poor quality roofing membrane breaks quickly and swells quickly after assembly. Then its remains are blown out by air currents towards the ridge, so after two years traces of its existence are insignificant.
What are the characteristics of a roof membrane?
There are several data that determine the effectiveness of a roof membrane. Most often this is information available on price lists or on product labels. Unfortunately, they can be significantly at odds with reality by examining these membranes, which are made in different atmospheric conditions. The lighter the condition, the better the result for the client.
Diffusion membrane often referred to as waterproofing or vapor barrier, but such names overlap with other broader concepts. Will be right call the upper membrane namely a diffusion membrane , since, regardless of what purpose it is, and by what technology it is made, it will still participate in diffusion of water vapor with simultaneous waterproofing protection against condensation moisture.
How to care for the roof membrane when installing the cover?
The second indicator is the weight, which measures the thickness of the roof membrane - the membrane, square meter which weighs 125 grams, is the most common on the market. Generally, the thicker the membrane, the better. Any damage to the diaphragm during assembly must be repaired using appropriate tape. Dripping oil chains are very harmful to the roof membrane because it chemically reacts with its structure, causing the holes to burn progressively.
The roof is one of the most important building elements and at the same time very complex. Prefabricated films and vapor barrier films are very important elements of every modern sloped roof. In combination with an insulating layer, they form an independent insulating partition. The comfort of the apartment largely depends on their proper functioning. The wrong choice of materials or the wrong installation leads to very expensive repairs.
Diffusion membrane always mounted on the outside of the structure ... The use of such a film on the inside of the structure will lead to unhindered penetration of vapors into the thermal insulation layer, which will require a qualitative improvement of the upper membrane, which will be able to remove all vapors from the roofing structure. We can say that using a diffusion membrane from inside the room is pointless - the effect will be exactly the same as if it is not there at all.
Choosing the right type of foil for a specific roof solution in a situation with a very wide range of different products is not an easy question, even for people with extensive construction experience. This is due to the most different ways definitions of product data by manufacturers and distributors.
Regardless of the type of roof, this is important. In the case of roofs, it protects the interior of the building from rain, snow and dust and can be covered with sheet metal from falling drops. With this low level of vapor permeability, it is very important to provide adequate ventilation under the preliminary mantle layer. It is very important for the investor to ensure that the film is used for many years.
High quality diffusion membrane for pitched roofs.
It is mounted directly on the insulation. It is made of two layers of non-woven polypropylene and an inner functional layer, which are connected into one membrane at the molecular level using ultrasound.
- DELTA VENT-N - Without self-adhesive strips. Adhesive tape is required to connect the canvases.
- DELTA VENT-N PLUS - With self-adhesive strips. No tape is required to connect the canvases.
- Weight: 150 grams / m 2
- Sd 0.02 m 6.0 x 10 -3 mg / (m x h x Pa)
Diffusion film for continuous flooring.
Another problem is the choice of foil system for a residential building with an attic. Always use a two-layer system on pitched roofs, from the top of the pre-coat and from the bottom of the vapor barrier. At the same time, it must provide the ability to wash out excess water, which, even in the presence of a vapor barrier, to some extent penetrates the thermal insulation of residential premises. On the other hand, the vapor barrier should stop the water vapor generated by the residents from entering the insulation layer and the roof structure.
Diffusion film with increased breaking characteristicsrecommended for installation in winter on a continuous flooring.
- High strength will avoid tears during installation, while maintaining the integrity of the waterproofing.
- Excellent steam permeability helps to keep the insulation dry, preventing snow from blowing out and thereby minimizing the cost of heating the house.
- Delta Vent-S without self-adhesive strips. Adhesive tape is required to connect the canvases.
- Delta Vent-S with self-adhesive strips. No tape is required to connect the canvases.
- Weight: 150 grams / m 2
- Equivalent diffusion thickness: Sd 0.02 m
- Vapor permeability coefficient: 4.5 x 10 -3 mg / (m x h x Pa)
It has adsorption bottom layer able to hold water
In practice, films with low water permeability are rarely used today due to the need for a ventilation gap between the foil and the thermal insulation layer. It is difficult to make such a layer a complex roof - in this case it is not recommended to use this type of foil.
Much clearer and easier to use are pre-melted films with high vapor permeability. They are increasingly replacing technologically advanced materials. The main advantage of open diffusion films is the ability to use full-length rafters for thermal insulation without fear of warming. They do not require a ventilation gap between the insulation and the foil and are therefore easier to install. The roof is denser and therefore "warmer".
- Can be used for both pitched roofs and ventilated facades.
- Has maximum strength.
- Delta MAXX - No self-adhesive strips. Adhesive tape is required to connect the canvases.
- Weight: 190 grams / m 2
- Equivalent diffusion thickness: Sd 0.15 m
This is a diffusion membrane with both anti-condensation and diffusion properties.
It has adsorption bottom layerwho in extreme moments able to hold water (up to 1000 g / m 2), keeping the insulation and roof structure completely dry.
This value is ideal for all insulated roof structures. Sometimes even products with lower vapor permeability are also recommended because they have other important advantages and are classified as open diffusion membranes.
Most of the most popular membranes on the market are made from polypropylene and polyethylene. There are single or multi-layer open roof diffuse membranes on the market. Among the multilayer layers, there are usually three-layer membranes made of a thin film, which are responsible for waterproofing and vapor permeability, and two layers of reinforcing non-woven materials and protecting the film. Nonwovens are usually made from polypropylene and polypropylene or polyethylene films. Of these products, the best performance is the highest thickness.
- It has a high vapor permeability (Sd \u003d 0.15), due to which it provides quick drainage of water and moisture from structures.
- It can be used for both pitched roofs and ventilated facades.
- Has maximum strength.
- Ensures the safety of roofers.
- Delta MAXX Plus has integrated adhesive strips for joining fabrics.
- Weight: 190 grams / m 2
- Equivalent diffusion thickness: Sd 0.15 m
Energy-saving diffusion membrane of extremely high strength with an absorption layer and two adhesive stripes.
Products with an additional reinforcing layer as well as hydrophobic materials are becoming more and more common. If a full roof is to be used on a roof, it is important to decide how durable the product is, as there is a high risk of damage during installation by contractors.
Most membranes have a "cover time" of 2 to 6 months. The longer this time, the better product, but it has already been adopted for 2-3 months. If the roof has a lower slope angle, the product with the highest water resistance and the entire system of adhesive and sealing additives must be used.
- Double layer diffusion roofing membrane for pitched roofs.
- High tensile non-woven polyester backing and breathable polyurethane cover. Primary raw materials.
- It is mounted on a heater.
- Effective roof protection against condensation due to its high absorption capacity.
- Has two built-in self-adhesive tapes along the edge of the roll.
- Weight: 210 grams / m 2
- Equivalent diffusion thickness: Sd 0.15 m
Diffusion membrane for continuous flooring to create a waterprooflower roof.
Despite the slightly higher cost, these are the most recommended products because they make the roof feel airy and warm. A tiled layer made in a full draft and moisture resistant system, while open diffusion is the most economical solution and the higher cost of such a solution is fully justified.
When designing the roof of a building where it will be attic, it is important to remember that what is underneath the roof is critical. It not only provides adequate thermal insulation, but also provides ventilation and adequate protection with membranes and roofing sheeting. The roof is visible as a whole, although in essence it is a complex structure, consisting of several layers, forming a coherent system of protection of the attic not only from precipitation, but also from winter heat loss, excessive heating in summer and proper ventilation of the room.
DELTA FOXX is a diffusion membrane with high water-repellency... With a high vapor permeability, this film has a compacted bottom layer structure, which gives a waterproof roof deck.
- Increased tensile strength will avoid damage during installation and during operation of the roof.
- Recommended for use on piece roofs made of slate or wooden shingles.
- Mounted only on a solid base... Is an reliable protection not only from rain, but also from melt water.
- Weight: 150 grams / m 2
- Equivalent diffusion thickness: Sd 0.02 m Vapor permeability coefficient: 4.5 x 10 -3 mg / (m x h x Pa)
Diffusion membrane for waterproof bottom roof.
Basically, a roof compartment is made up of six layers: the roof, the ventilation duct, the high permeability membrane, the insulation layer, the roofing film, and most often the gypsum board from the inside. Each of these elements is responsible for the smooth operation of the roof. It is especially important to choose high quality vapor barrier films and roofing membranes. They first protect the insulating material from moisture from the inside, which can significantly reduce the thermal insulation of the insulating barrier. The diaphragm is mounted outside the insulation. They not only provide effective moisture protection, but also allow the release of water vapor indoors.
Diffusion membrane for waterproof bottom roofing ”- a waterproofing base for flat roofs and for extreme weather conditions.
Complies with Class 1 of the industry regulation of the German Roofers Association (ZVDH).
- Hot air welded or glued (cold diffusion bonding).
- Record strength and durability.
- Suitable for use as a temporary roof.
- Weight: 350 grams / m 2
- Equivalent diffusion thickness: Sd 0.27 m
Diffusion membrane with a volumetric structured layer for folded metal roofs.
Only the use of a low bore membrane requires 2 cm of clearance. Another important layer is the ventilation gap, the space between the membrane and the tile. This significantly affects the lifespan of planks, adhesives and roofing membranes and reduces the likelihood of moss growth.
The high-quality roofing membrane guarantees the protection of the roof, attic and other rooms in the house on long years... There is a wide range of these products on the market and they are changing in many ways, for example, in terms of production technology, finishing additives, waterproofing - coating hygiene - impregnation, mechanical strength - tear resistance. As technology advances, new opportunities appear in the market.
- Membrane Delta trela is a Delta Vent S diffusion membrane, on top of which a three-dimensional three-dimensional lattice with a height of 8 mm made of polypropylene threads is applied. Such a structure provides a reliable basis for the subsequent installation of a folded or metal piece roof, at the same time ensuring the removal of excess moisture from the insulation, as well as successful ventilation of condensate in the space formed by the volumetric grating.
- Supplied includedwith specialized nails with EPDM sealing gasket for the most sealed fasteners.
- Delta trela No self-adhesive strips. You will need tape and glue to connect the canvases.
- Delta trela plus has integrated strips for joining the canvases.
- Weight: 380 grams / m 2
- Equivalent diffusion thickness: Sd 0.02 m
Micro-perforated waterproofing membrane for double ventilation gaps.
What is the direction of aperture selection?
An interesting suggestion is the reflective membrane. Otherwise the waterproofness of a membrane is its strength against the thickness of water, which is caused by a special protective coating, advises Marek Podeszwa. A roofing membrane, like any other material, grows and thereby reduces its strength. Their low diffusion resistance prevents too much moisture from accumulating in the insulation layer. Steam barriers in roof technology are designed to protect the insulation from moisture that occurs in the form of water vapor constantly flowing out from the inside of the house, from all utility rooms.
Film Dragofolrecommended for use on not insulatedpitched roofs, or insulated roofs of simple shape and length of the slope up to 5 lmat an angle of inclination not less 30 degrees.
Requires double ventilation gap: between the insulation and the film, and between the film and the solid base of the roof.
Not allowedinstallation directly on top of the insulation. Not allowed installation on a solid base.
Waterproofing film? made of reinforced polyethylene with microperforation and ensures the removal of water vapor from the lower ventilation space. It is also a windbreak for insulation.
No self-adhesive strips. Adhesive tape will be needed to connect the canvases.
Weight: 140 grams / m 2
Equivalent diffusion thickness: Sd 3 m
In new homes, this can also be from fresh walls, plaster, and even floors. Air absorbs a certain amount of moisture, but as the temperature decreases, its absorption also decreases. When excess moisture is not removed, it can reach the so-called. condensation, that is, condensation of water from the air on the surface of the partition from the warmer side. This phenomenon is most noticeable on the surface of window panels, the temperature of which is lower than at home. We must be aware that a periodic increase in humidity occurs in every building, even with efficient ventilation.
Breathable waterproofing membrane over a continuous deck.
DELTA-FOL PVG is used as a release layer in standing seam roofs made of copper, steel, aluminum and zinc instead of bitumen rolls.
- For roofs made of natural or artificial slate, it is used as an underlay.
- Leaves a solid roof base always dry.
- It can be used on continuous flooring as a "breathing" underlay for small piece roofing materials and folded roofs. Allows to dry a solid base after finishing roofing works.
- The film can also be used as a vapor barrier in roof structures with insulation over the rafters.
- The high strength of the Delta-Fol film provides durability during roofing work, and this film can also remain uncovered with roofing material for 6 months.
- Weight: 210 grams / m 2
- Equivalent diffusion thickness: Sd 3 m
One-layer hydro-windproof membrane with good vapor permeability for roofs and walls.
- The Tyvek Solid membrane has improved strength characteristics and greater weight.
- It can be used not only for waterproofing of pitched insulated roofs with one ventilation gap, but also for facades - improved strength characteristics will cope with the wind load arising in ventilated facade systems.
- Has a single-layer fiber structure made of 100% HDPE (high strength low pressure polyethylene). The outer side (front) is color-coded for easy installation. It is mounted only with colored side up.
- Has improved performance on the ability to hold a water column.
- Effectively conducts moisture from the under-roof space or from the facade insulation through its structure, keeping the structure of the roof and walls dry, keeping them bearing capacity and strength characteristics.
- Tyvek HouseWrap is mainly used in ventilated facade systemswhere large wind loads arise, especially with a high number of storeys of the building.
- So, to protect the layer of thermal insulation from blowing out, a windproof film Tyvek HouseWrap is used, which also has waterproofing properties to high wind resistance parameters - it passes warm air to its front side, keeping the insulation dry.
- It is lightweight, which greatly facilitates installation on large areas. At the same time, it has improved tensile characteristics: 300/310 N / 50 mm.
- Weight: 61 grams / m2
- Equivalent diffusion thickness: Sd 0.02 m
Previously in Russia, materials such as roofing felt or glassine were used as roofing insulation, but these materials are much inferior to the quality, functionality and durability of modern roofing materials.
So, glassine and roofing felt last about 3-5 years, degrading over time. They are actively affected by moisture. Another huge disadvantage of these materials is their dangerous flammability.
When choosing a film, you should pay attention first of all to its type: there are materials with high and limited vapor permeability (that is, "breathable" or "non-breathable").
Despite the vapor barrier, part of the water vapor still penetrates the thermal insulation. If there is good ventilation for the roof structure, this is not dangerous (steam is blown out by the supply air), but only on the condition that the steam passes through the insulation and enters the ventilation gap, which means that the roofing film should not interfere with its exit.
Diffusion membranes differ from each other in their technical parameters: basic material (polyethylene, polypropylene, etc.); strength, ability to diffuse, waterproofing properties, flammability, service life and other parameters.
The diffusion membrane is selected for each roof based on the operating conditions of the roof, the purpose of the building and the type of roofing.
Modern waterproofing films are also called anti-condensation films or diffusion membranes, or windproof films. All these names - refer to one general concept.
Such under-roofing films have some common properties:
- wind protection (films protect the insulation from damage due to blowing in a drop of rain or snow, actively remove the resulting moisture from the main structures.)
- protection against under-roof condensate leaks (diffusion membranes tend to release warm air vapors to their outer side, where condensation occurs, and such a film does not let the resulting water drops back into the roofing cake).
- in general, all films are designed to help keep internal structures dry - since moisture is the main enemy of the integrity and strength of walls and roofs.
Scope of waterproofing films:
- protection of the under-roof space (in the case of roof insulation)
- protection attic space - wind protection (for cold attics)
- insulation protection in ventilated facade systems (when facing with vinyl siding, metal siding, facade cassettes, etc.)
- wind protection of walls when facing the facade with any facade materials, with the exception of wet facades.
Also roofing waterproofing films differ in:
- its diffusion properties (vapor permeability index)
- its mechanical characteristics (tensile strength)
- heat resistance (different types of roofing coverings are heated in different ranges, respectively, the under-roofing material must meet these characteristics)
- density and type (there are films based on polypropylene, there are films based on polyethylene. The higher the density, the stronger the film).
- the ability to withstand a water column (an important indicator, especially for a roof, because the formed condensate sometimes accumulates on the outer side of the film in places of sagging, and the film must have sufficient properties so as not to leak)
- service life
Breathable and non-breathable under-roof waterproofing films
When choosing a roofing film, it is necessary to pay attention to the type of its vapor permeability: high or limited vapor permeability. ("Breathable" or "non-breathable" roofing films).
"Non-breathable" films presented on the market by the products Yutafol (JUTA, Czech Republic), Eurofol (BRAAS, Germany), Dragofol (DORKEN, Germany), Takofol (TAKOTTA, Finland), Technonikol (TECHNONICOL, Russia), Izospan ("GEXA", Russia) and others.
The main dignity such films are good waterproofing properties and low price compared to breathable. However, the design with their use is not always cheaper. The fact is that the lower ventilation gap is created with the help of additional bars mounted on top of the rafters. This means more wood will be required and supplies - antiseptic and fire retardants, fasteners.
Plus the extra time, effort and money spent on assembly work... But there is also a more serious drawback: on a roof of a complex shape (with ridges, valleys, abutments, several dormer windows, etc.) it is extremely problematic, and often it is impossible to provide the necessary air flow in both ventilation gaps (primarily in the lower one), moreover, in each rafter span. Another disadvantage of such a design is the high risk of moistening the insulation with water vapor, penetrating from the premises under the roof through the non-glued overlaps of the vapor barrier rolls, unsealed adjoining of the film to walls, pipes, skylights.
Among the "non-breathing" films can be distinguished microperforated, with the smallest holes for steam outlet.
It is worth paying attention: despite the perforation, the vapor permeability of such films is not enough for mounting them directly on the insulation.
"Breathable" (diffusion) - these are the materials Delta (DORKEN, Germany), Tyvek (DUPONT TYVEK, Luxembourg), Elkatek (ELTETE, Finland), Yutavek (JUTA, Czech Republic), Divoroll (BRAAS, Germany), Technonikol (TECHNONICOL, Russia ) and etc.
Products are membranes with micropores (do not confuse with microperforation!), Which freely pass water vapor, but do not allow external moisture to pass through. Membranes are free from the above disadvantages inherent in "non-breathable" films. In particular, they can play the role of wind protection, allowing you to save energy spent on heating the attic. These materials are used on roofs of complex configurations, they are easier and faster to install. However, membranes are about twice as expensive as non-breathable films.
Wind protection for walls with high strength characteristics.
The article tells about the main properties of materials present on the construction market that protect the roof from moisture. In order not to be mistaken in the choice, we will consider the features of choosing a particular material depending on the type of roof and the type of roofing.
- Vapor barrier films
- Perforated waterproofing films
- Waterproofing films with anti-condensation coating
- Membranes.
STEAM INSULATING FILMS
Application. Vapor barrier films are used in houses with insulated roofs to isolate insulation from vapors that rise from inside the house.
Installation. It is very important to tightly perform all the joints of the vapor barrier (between the sheets of the film and at the points of abutment to the structural elements). In case of leaky joints, humid air from below (from the premises) will penetrate into the thermal insulation and worsen its properties. (These 2 paragraphs are on a different topic, so don't start with bullets.)
Choice. When choosing a vapor barrier, you need to pay attention to the vapor permeability of the material - δ (mg / m2 * h * Pa). Water vapor permeability shows how many milligrams of water vapor passes through a 1 sq. m for 1 hour (while the air temperature on both sides of the film is the same, and the difference in the partial pressure of steam is 1 Pa). The lower the vapor permeability number, the better the vapor barrier. (in the description of membranes below - another unit of measurement, you only need to select one ..)
WATERPROOFING PERFORATED FILMS
Application. Perforated waterproofing films can be used with all types of roofing.
Installation.The vapor permeability of these films is lower than that of thermal insulation, therefore, when installing them, it is imperative to make 2 ventilation gaps (for a description of ventilation gaps, see the article ).
Benefits:
- Low price. However, it is worth checking whether the roof structure is actually cheaper with such films than a roof with a membrane. As described, such films can only work successfully if there is a lower ventilation gap - between the thermal insulation material and the film. The lower ventilation gap is made with an additional lathing, which is mounted over the rafters. Thus, more wood will need to be used. In addition, you will need more consumables: antiseptic, antipyretics, fasteners and additional time for installing the roof.
- Such a film is the most economical (in comparison with membranes) option for waterproofing pitched roofs with a cold attic, it protects the thermal insulation of the floor top floor from moisture. If, however, a membrane is installed in this structure, then some of its characteristics will simply not be used, and perforated film is the best price / quality ratio for such a roof.
Disadvantages:
- If the roof has a complex shape (several valleys, transitions, different levels, roof windows etc.), then it is not easy to provide a ventilation passage free for air flow (especially in the inter-rafter space). In this case, there is a threat that the humid air will not be able to completely erode from the insulation, therefore, remaining in it, moisture can lead to the formation of fungus and mold.
- Such films are more difficult to install than membranes, since you need to make an additional crate for insulation for the device of the lower ventilation gap, as mentioned above.
Choicewaterproofing films should be based on:
- Water resistance (waterproof). Waterproofness, as the name suggests, is the ability of a membrane to resist moisture penetration from outside - rain, snow, etc. It is measured in millimeters (mm) of water column. This indicator should be at least 0.3 m. Water column. If the water resistance of the film is lower, then it cannot serve as a temporary roof even for a short time, so it must be covered with roofing material immediately after installation.
- Resistance to infrared (IR) radiation, since the film is exposed to a strong heat flux, and the UV resistance time must be at least 2 months.
- Strength. Strength must be no less than 150 N / 5cm
ANTI-CONDENSATE FILMS
Application. They are used with metal roofs - metal tiles, folded roofing.
Installation.The fleecy side of the film absorbs moisture, preventing it from entering the inner surface of the roof. Therefore, you need powerful ventilation of the under-roof space to remove moisture drops. For these purposes, it is imperative to make the lower ventilation gap.
- Films of this type protect the inner surface of the roof from moisture, but do not protect against condensation in the summer, when moisture penetrates under the roof from the outside during hot hours of the day and cools down at night.
Choice. When choosing an anti-condensation film, you need to pay attention to vapor permeability. It should be close to zero (about 0.3 g / m2 hPa) in order for the film to provide maximum protection metal roof from condensation and subsequent corrosion.
DIFFUSION AND SUPER-DIFFUSION MEMBRANES
Application. Membranes CANNOT be used in conjunction with roofing materials with high thermal conductivity: metal tiles and euro-slate *. The exception is special volumetric diffusion membranes (see below). CAN be used with ceramic, cement-sand, bitumen shingles, or composite metal tiles - these roofing coatings have a lower thermal conductivity than plain metal and corrugated roof tiles. In addition, a layer of acrylic primer on the inner surface of the composite metal tile protects it from moisture.
Installation. They are mounted on roofs of complex configurations, since it is difficult to make a lower ventilation gap on them with the help of an additional lathing.
Benefits.One upper ventilation gap is needed (saving materials, since no additional lathing is needed).
* The issue of using membranes with Euroslate is still controversial, and there are no final recommendations. In this case, we were guided by the fact that the Euro-slate has a high thermal conductivity.
VOLUME SEPARATING DIFFUSION MEMBRANES
Application. They are used for seam and other metal coatings - zinc, copper, steel, aluminum. Particularly good for titanium-zinc coatings on gentle slopes (3-15 °). Also recommended for complex roofs.
Benefits:
- Protects the roofing from condensation, as there is constant ventilation thanks to the volumetric grille.
- Only one upper ventilation gap is needed, which is often provided by the membrane itself.
Choice. For membranes, the main indicator of quality when choosing is vapor permeability. According to European standards, vapor permeability is assessed using the Sd value - an indicator of the thickness of the resistance to diffusion of water vapor, while the lower its value, the better the membrane: from 0.02 to 0.4 m. According to Russian standards, the vapor permeability of membranes is measured in g / (m2 day): at the higher the figure, the greater the permeability of the film: the optimal (sufficient) indicator is 1000-1100 g / (m2 day)
Anti-condensation films, as well as membranes, according to builders, are best suited for attics. Choice between anti-condensation films and diffusion membranes depends on the used roofing material:
- diffusion, super-diffusion membranes are mounted with one upper ventilation gap (between the membrane and the roof) - under roofing with lower thermal conductivity: natural and cement-sand tiles, bituminous shingles etc.
- volumetric membranes are mounted, they are mounted with one upper ventilation gap (between the membrane and the roof) - under the metal roofing.
- anti-condensation films - they are mounted with two ventilation gaps - upper and lower.
Suitable for metal roofing - metal tiles, corrugated board, standing seam roofing and euro slate.
Let's summarize everything mentioned above by considering the use of roofing waterproofing materials with concrete roofing in heated houses.
Roofing made of soft (bituminous) tiles
As waterproofing, it is possible to use diffusion and superdiffusion membranes with one upper ventilation gap, or waterproofing films made of polyethylene or polypropylene - when installing two ventilation gaps. The rafters are installed, then waterproofing is placed, a counter-lattice is laid on top, then a lathing, solid flooring, tiles, insulation (thermal insulation) and then vapor barrier.
* Installation of waterproofing films is carried out by the same method for roofs with any coating. Read more about the installation of waterproofing and vapor barrier films in the next article.
Metal roofing (without internal acrylic coating)
An anti-condensation film is recommended as waterproofing, since the metal has a high thermal conductivity, and condensation appears on the lower surface of the metal coating with a daily temperature drop. It is also possible to use waterproofing films. DO NOT USE DIFFUSION MEMBRANES *, except for special volumetric separating diffusion membranes (see article "Roofing films and membranes. Types and materials of roofing films and membranes").
To eliminate moisture between the metal tile and the waterproofing, an upper ventilation gap with a height of about 40 mm is created using the crate. A lower ventilation gap is provided between the thermal insulation and the waterproofing. From below thermal insulation material (insulation) is protected by a vapor barrier film. The vapor barrier is mounted on the inner surface of the rafters with a stapler - a staple gun, overlapped and connected with adhesive tape.
* You can read more about installing anti-condensation film in the next article.
Composite metal roofing (with internal acrylic coating)
From below, the thermal insulation is protected by a vapor barrier. It is also possible to use waterproofing films as waterproofing, while two ventilation gaps are arranged.
* More details about the installation of diffusion membranes - in the next article.
Natural tile roof
It is recommended to use a diffusion and superdiffusion membrane with a single upper ventilation gap as waterproofing. Waterproofing films are also used. As a vapor barrier that protects the thermal insulation from below - a vapor barrier film. When using waterproofing films, two ventilation gaps are arranged - an upper and a lower one. 
Slate roof
Asbestos-cement slabs - it is possible to use as a waterproofing diffusion and superdiffusion membrane with the device of one upper ventilation gap between the membrane and the roof.
It is also possible to use waterproofing films made of polyethylene or polypropylene, then you need to arrange two ventilation gaps - upper and lower (between thermal insulation and waterproofing). A vapor barrier film is used as protection against steam from the inside.
Euroslate roof
Euroslate has a high thermal conductivity, with a daily temperature drop, condensation appears on its lower surface.
Therefore, anti-condensation films and other waterproofing films are used as protection, and DO NOT USE DIFFUSION MEMBRANES (as mentioned above, this is a controversial issue). Two ventilation gaps are required, an upper and a lower. A vapor barrier film is used to protect the thermal insulation from steam from the inside.
Seamed roof
It is also possible to use waterproofing films (both perforated and non-perforated) made of polyethylene or polypropylene and vapor barrier films with two ventilation gaps. DO NOT USE DIFFUSION MEMBRANES, except for special volumetric separating membranes for metal folded roofs (see article "Roofing films and membranes. Types and materials of roofing films and membranes").
Slate roof
It is also possible to use waterproofing films made of polyethylene or polypropylene and vapor barrier films with two ventilation gaps.
In unheated homes and homes with cold unheated attics vapor barrier is not satisfied. Only waterproofing is laid. It is recommended to use a perforated waterproofing film made of polyethylene or polypropylene for these purposes.
