Waterproofing of the roof of the house for metal tile: materials, installation

The main purpose of the roof is to protect the premises from a number of climatic factors: precipitation, temperature, wind and humidity. Therefore, the construction of a modern roof consists of several layers, which ensure its durability, reliability and high thermophysical parameters. Waterproofing the roof of the house under the metal tile is one of the stages of protecting the residential object from the penetration of moisture into the insulation and supporting the microclimate in the room.

Elements of pitched roof

Building a house involves creating an object with a stable, comfortable temperature and the relative humidity of the air inside it. A modern erection of housing is also based on the preservation of expensive heat in it. The difference in temperature inside and outside the room leads to the appearance in the layers of the roof of various thermophysical processes. This causes the use of different building materials in the structural elements of the roof, each bearing its own function.

Basic layers:

1. Bearing roof system - rafters.
2. Steam insulation.
3. Thermal insulation.
4. Lower and upper laths.
5. Control grating.
6. Waterproofing.
7. Roof covering.

If you neglect at least one of the listed items, you can suffer from the leakage of the roof, the appearance of a pungent odor and, as a result, the destruction of the rafter system.

Steam insulation and waterproofing

These two layers in the upper structure of the building have different functions. Steam insulation is placed under the insulation, thereby protecting the main material from fumes coming from inside the house. But the waterproofing is mounted on top of the insulation, that is closer to the roofing material. This is if these activities are carried out during the new construction. If the top structure of the building is not reconstructed and the attic space or attic is insulated, then the roof is waterproofed from inside the house and the moisture-proof functional layer is laid under the control bar.

That is, the main purpose of these layers: fencing the insulation from the condensate on top of the structure, and from below - evacuation of water vapor from within the living space.

Material selection

From the type of roof, pitched or flat, and from the main cover depends on the choice of the material acting as moisture protection. For example, the waterproofing of the roof of the house under the metal without the use of a heater, the so-called roofs with cold attics, allows the use of ruberoid and pergamina. They are a good protection against moisture, wind and dust, but the operational period is short-lived. Their main advantage is low cost.

Waterproofing the roof of the house under the soft roof requires the use of materials based on cardboard or fiberglass, with different impregnations, for example: roofing felt, ruberoid, glass.

On the flat upper structures of the building or with a slight slope (up to 3%), as waterproofing, mastic sealants can be used: bitumen, polymer or bitumen-polymer.

Materials for waterproofing the roof of the house under the metal roof in warm attics should be more resistant to condensation. Since the temperature difference is significant, because under the roof is a heated room, respectively, and the probability of moisture is higher. Modern construction in this case involves the use of materials based on polypropylene.

What is the waterproofing of the roof of the house for metal roofing? Types of Films

The simplest for performance characteristics and cheap material is considered a classic polyethylene film. As a rule, it is mounted for pitched roofs for slate, corrugated board, metal and ceramic tiles. And it is used in combination with mineral wool and expanded polystyrene. Can be reinforced or not. Unreinforced polyethylene has three times less properties than a strengthened analogue in its transverse and longitudinal fracture properties.

A more durable and reliable material with high vapor permeability among film waterproofing agents is the diffusion membrane. This insulation material is similar in properties to human skin: it also does not let the moisture inside, but it perfectly removes it from the inside.

Antikondensatnaya film - this is the best waterproofing of the roof of the house. Metal materials, such as tiles or profiled sheets, have a high thermal conductivity, resulting in condensation. Films with protection against moisture penetration are endowed with the properties of absorbing it. Therefore, when installing it, a requirement is made: the presence of a lower gap between the heater and the waterproofing so that moisture from the material can be eroded.

Diffusion membranes

The advantage of these building materials in high vapor permeability. They are used to convert a cold attic without changing the truss structure, as well as for roofs in the attic. According to the ability of membranes to pass steam, they are divided into:

• Pseudodiffusive membranes, the vapor-permeability of which is 20-300 g / m2 per day. This indicator is insufficient to neglect the ventilation gap.
• Diffusion films (400-1000 g / m2), the ventilation space can not be done.
• Superdiffusion membranes, capable of passing more than 1000 grams of steam per day through 1 m ² . Therefore, manufacturers of such a waterproofing film allow for the absence of a gap between the heater and the superdiffusion membrane.

Important! Since the membrane is a perforated film and passes through itself incoming steam from the room, its use is prohibited in metal roofs. Therefore, the waterproofing of the roof of the house for metal tiles excludes the use of membrane films. The material can be used for composite metal, cement-sand, ceramic tiles.

Ventilation gaps

Waterproofing the roof of the house under the metal tile provides in the insulating cake small spaces between the layers. This is necessary for air circulation and removal of condensation. The upper ventilation gap is arranged between the main roofing material and the protective waterproofing film. It does not allow moisture to get on the heater, which is the bottom layer behind the film. And also the waterproofing material passes through itself evaporation, coming from the side of the heater. Therefore, it is important that the moisture barrier material has a good vapor permeability.

The lower ventilation gap is created between the heater and the film. This allows the multi-layer structure to be ventilated and keep the wooden and thermal insulation elements of the roof within the limits for normal operation.

Experts' opinions about the arrangement of the lower gap between the membrane and the heater are divergent. Some say that the ventilating layer is not needed, since the membrane type of waterproofing is highly vapor-permeable and there is no condensation, and the second experts nevertheless strongly recommend leaving the lower gap between the listed elements of the structure. In the case of metal and the use of anticondensate films, both gaps are a must.

When there are no gaps

When waterproofing the flat roof of the house on a concrete base, use liquid glass, rubber spraying or roll, bituminous materials. In this case, the layers of the upper structure of the building are laid without gaps.

If roll materials are used, then a primer is applied as a waterproofing before they are welded. In addition, it is possible to protect the roof from moisture with the help of paint materials, which cover the main waterproofing layer.

For mastic roofs, a waterproof carpet is formed with a glass fiber mat impregnated with hot bituminous or rubber bituminous mastic.

Factors determining the choice of waterproofing material

• The purpose of the upper structure of the building. A cold attic or a heated room under a roof.
• Constructive type of roof: a complex configuration, pitched or flat.
• Roofing material: profiled sheet, metal, slate, mastic.
• The presence of insulation.
• Cost and installation methods.

Installation of waterproofing carpet under metal roofing

When the rafters are prepared, the cornice board is mounted, all the structural parts of the roofing system are impregnated with antiseptic, the stage of laying the waterproofing layer begins. The film is rolled out by horizontal lapped strips, beginning from the eaves, gradually rising to the roof ridge. Fastens the material to the rafters with a staple gun. And joints of strips are pasted with an adhesive tape. The waterproofing layer is mounted with a 2 cm slack to avoid a drop in the temperature of its rupture.

Over the waterproofing carpet are packed along the rafters of the beams 50x50 mm. The next stage is the installation of a crate of boards of 32x100 mm in steps equal to the step of a wave of metal tile. Then the main roofing material is mounted with screws.

Conclusion

Roofing is a system whose longevity depends on the reliability of the constituent elements and the correct installation. Therefore, in order to avoid leaks, it is necessary to approach professionally the choice of underlay materials and the nuances of their installation.

Waterproofing the roof of the house for profiled sheeting, metal tile is a polypropylene fabric with a pile on the inside, thanks to which the moisture coming from the room is absorbed. Therefore, additional dampness in the elements of the roof does not occur, which prevents corrosion of the metal.

Popular roofing anticondensate films on the Russian market: "Yutakon", "Stroizol", "Ranka".