Waterproofing of the roof of metal

Successful exploitation of the roof coveredmetal tile, its longevity is largely dependent upon the creation of the optimal temperature and humidity conditions in the roof space. We know that sometimes the condensation on the inside of the roof covering, which, penetrating into the insulation, can damage its functional properties, and even penetrate into the living quarters. In order to avoid such negative phenomena carried the roof waterproofing of metal.


  • What is the roof waterproofing of metal?
  • Types of waterproofing under roof metallocherepichnoy
  • Preparatory work
  • Installation of the waterproofing step by step

What is the roof waterproofing of metal?

Conduct metallocherepichnoy roof waterproofingnecessary for several reasons. Chief among them - the roof protection against contact with water, since water destroys the building materials, particularly metal. Even when installing a new slab is required to conduct a waterproofing, moisture as a means not only water but also the condensate which is formed during the temperature drop. Therefore, the main tasks under the metal roof waterproofing are:

  • exclusion of penetration of external moisture (melted snow and rain water);
  • to prevent accumulation of condensate in the insulation;
  • maintaining the insulation is in good condition;
  • preventing the ingress of dust and dirt in the roof space.

Waterproofing is an important milestone competent roofing, which ensures reliable operation of the house for a long time.

Waterproofing roof metallocherepichnoy

Waterproofing of the roof under the metal roof to protect from the effects of atmospheric moisture and prevent the formation of condensation on the inside roof deck

Types of waterproofing under roof metallocherepichnoy

Waterproofing materials are different andselected depending on needs. For example, the temporary protective film may come cheap, you should buy a waterproofing membrane for the permanent protection. How do they differ?

Plain film for waterproofing consists ofthe base layer and polyethylene. It only protects the internal overlap and often used only as a temporary measure (for example, during repair) to prevent precipitation in the house. Accordingly, the price of this type of materials is very low.

Types of waterproofing film

Waterproofing materials are different and are selected according to the needs

If waterproofing is necessary to install onetime for many years, should buy a more expensive option - a waterproofing membrane, which is characterized by practicality and durability. It consists of a reinforced and absorbent layers, which perfectly complement each other. Reinforced layer perfectly protects the surface from precipitation and absorbent, respectively, absorbs moisture, preventing the appearance of condensation and mold. It is obvious that such a material will have to spend fairly, but it will avoid problems with the roof in the future.

In roofs with a cold attic for waterproofingunder the metal used, as a rule, asphalt and roofing felt. They provide good protection from wind and moisture, but when exposed to increasing pressure, have a short life span. For a mansard roof should choose higher-quality materials, such as waterproofing film based on polyethylene.

Film for waterproofing under metal roofing is of three kinds:

  • classic (it has dual-circuit insulation);
  • superdiffuzionnaya membrane (with the single-insulated, increasing the lifespan of roofing insulation);
  • anti-condensate (a dual-circuit ventilation, fleecy material that absorbs moisture).

Preparatory work

Before you lay a waterproofing material, you need to competently make a preliminary roofing works:

  • roof system according to the calculations made in the design of the roof. This work is recommended to perform in dry weather;
  • laying eaves board in prearranged slots to attach rafters and fascia boards to the end of the rafters. These two elements will give additional rigidity to the structure;
  • the location of the gutter hooks for drainage systems.

Possible waterproofing assembly

Waterproofing under the metal roofing is installed in one of two ways:

  1. By rolling strips of film in parallelcornice. In this method, a film is mounted to a special sagging lathing apparatus. Overlapping strips should be at least 10 centimeters. And in order to provide ventilation between the film and the film is attached by means of a metal tile nadstropilnoy kontrobreshetki.
  2. By placing the film perpendicular to the eaves. Gidroizolyatsionnny material lay with the finished and already crate attached to the tightness. In this case, the overlap between the stripes of the film should be more than 10 centimeters.

Installation of the waterproofing step by step

Waterproofing metal roofing is laid withso that the air flows freely from the roof eaves to the ridge and out freely through the vents installed at the highest point of the roof, and through the ridge seals.

Laying waterproofing film

The film is laid horizontal stripes from the eaves to roof ridge with overlap (15 cm) and fastened to the rafters or joists

The film lay horizontal stripes oneaves to roof ridge with overlap (15 cm) and fastened to the rafters or joists using construction stapler or using nails stainless steel flat cap. To isolate overlapping locations using adhesive tape. Care should be taken so that overlaps the place fell on the wooden structures. Furthermore, when the film stacking slack should be left in between the rafters 2 cm. This is done in order to avoid excessive tension or film rupture during sudden temperature drops.

It is not allowed to confuse the part of the film. She laid the bright side edge tape to the roof covering.

This need to know! There is a rule: a rolled film, so it fits, it can not turn over, otherwise the waterproofing characteristics of the material are lost.

When using classical orAnti-condensation film is necessary to provide two-circuit ventilation, so in this case should not exceed the height of the rafters insulation thickness of 3-5 centimeters. If this condition is not met, then hammered wedges remote section of 3x5 centimeters. This will create a ventilation space between the insulation material and the waterproofing.

Not allowed film flooring directly on the formworkor other flooring, as well as contact with the heater. If gidrobarer placed on the repaired roof, which has a formwork or other flooring, then laid on the slope of the roof joists section 2x5 cm. The distance between them should be from 1.2 m or more.

roof structure of metal

It looks like the roof of a multi-layer cake with metallocherepichnoy coating

Upon contact with an insulating filmdecking it loses its waterproofing properties, so under the roof slope is necessary to ensure clearance of 5 centimeters, as well as take into account the air flow requirements for securing the edges of the material at the bottom of the roof. On the ridge ventilation space must be at least 5 centimeters. If the structure is provided with a lower groove, waterproofing film should reach to the edge of it, but if it does not exist - it is desirable to perform the bottom edge of the film, combining a roof gutter. All openings for the circulation of air flow performed so that through them they could not penetrate biological organisms - birds, insects.

To attach to the waterproofing layerroofing elements used rubber adhesive tape. At the junction rays film overlap should be 15-20 centimeters. At the exit stations and furnace vent pipes film stack on a data element walls with 5 cm overlap.

The only waterproofing material, whichIt does not require the presence of the gap over the insulation, a new progressive superdiffuzionnaya membrane. It can be rolled directly on the rafters. If rafter insulation thickness greater than the thickness, the rolling out of the membrane when wrapped around the rafter, repeating their profile.

In areas where there are attic windows,waterproof film is attached, guided by a specific design solution windows, because each manufacturer skylights gives its decision on fastening waterproofing to their own products.

After the laying of the waterproofing layeryou can proceed to the next stage of the device roof. Properly executed installation of waterproofing is the key to the reliability of the design as much as the roofing itself.

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