What is better to use for waterproofing the roof: the choice
When arranging the roof structure in a newly built house, you will definitely encounter a problem related to which waterproofing material is best used for the roof.
In this case, the choice of a suitable protective coating for you, as a rule, is determined by such external factors as:
- the nature of the climatic conditions in your area (the presence of sharp fluctuations in air temperature, rainfall, wind force, etc.);
- design features of the roofing system and the estimated load on it;
- cost of purchased material.
Types of protective coatings
As for the parameters of the waterproofing material itself, it must meet the following technical requirements:
- creating a minimum load on the roof system (i.e., the material must be sufficiently light and elastic);
- protection of the insulation layer from mechanical stress and moisture;
- ensuring the possibility of ventilation of the under-roof spaces in order to bring out water vapor (wet evaporation) formed in a residential area.
When considering the known types of waterproofing coatings, there are two main groups of materials: under-roofing films (perforated or with anti-condensate layer) and polymer membranes.
Note! So-called perforated films are usually placed between the coating and insulation and can be used in roofing structures of any class. Due to the low vapor permeability of film materials during their installation, it is necessary to provide special openings that provide the possibility of additional ventilation of roofing spaces.
Waterproofing films with anti-condensate layer, as a rule, are used on metal-coated roofs and do not need special ventilation. But when choosing this type of protective material, special attention should be paid to its vapor permeability.
Membranes
Waterproofing membranes have the unique ability to pass out the accumulated indoor steam, while also preventing the penetration of moisture into the space under the roof. Material of this type can be mounted directly on the insulating material (without arranging a special ventilation gap). In this case, condensation on the surface of the insulation is not formed.
Membrane protective coatings are widely used in buildings with heated roofing spaces, as well as in the conversion of cold attic rooms into residential lofts.
In terms of vapor permeability, all known membrane products are divided into two main classes. It:
- Pseudodiffusion membranes (the same perforated films with a low level of vapor barrier), needing to organize a special ventilation niche.
- Diffusion (superdiffusion) membrane films that do not require additional ventilation.
A cheap perforated film or a more expensive super-diffusion membrane can be used for roofs of conventional slate. In the latter case, the protective coating is placed directly on the surface of the insulating material. In this case, the total cost of arranging both types of waterproofing is about the same (although the membrane should be attributed to a higher quality type of protective coatings).
Video: mounting membrane roof
See also:
Installation of the membrane on the roof