Pie of metal roofing - types and arrangement
Experienced craftsmen rightfully call metal tile one of the most practical, affordable and reliable roofing materials. It is suitable for use even in difficult climatic conditions, as it has high weather resistance. However, in order for this functional coating to reveal its full potential, it is necessary to properly equip the roofing pie for it, using combined insulating materials. In this article we will talk in detail about the structure of the roof of metal.
Roofing Cake Composition
The metal tile is a profiled roofing sheets of galvanized steel with polymer coating, the relief of which resembles a wave. This material is recommended to use if the slope of the roof is 15-45 degrees. Roofing pie for this coating is made in such a way as to minimize its disadvantages - high thermal conductivity and resonating ability. Therefore, it consists of the following elements:
- Vapor barrier. This roofing layer is designed to protect the insulating material from exposure to air saturated with water vapor and condensate. It is made from durable polymeric materials.
- Thermal insulation. Insulation fits between the rafters to maintain the temperature of the roofing room. Mineral or polymeric materials are used as insulation for metal roofing.
- Waterproofing. Waterproofing is a mandatory element of the roof of metal, which serves to protect the roof frame and insulation from atmospheric moisture, condensate.
- Counterbribe. It is a 3-4 cm thick softwood slats. The counter grille is fixed along the rafters over the waterproofing to provide a ventilation gap.
- Crate. The metal tile is laid on a sparse crate of wooden bars or edged boards, the pitch of which is 50-100 cm, which provides lightness and durability of the roof.
Note! The finish coating, metal profiles, overlaps, so the roofs are sealed, well protected from leakage. The smaller the slope of the roof, the more do overlap during installation. Roofing pie under the metal provides durability of the finishing coating and the truss frame.
Types of roofing pie
Depending on the shape and purpose of the roof, the roofing cake for metal tile flooring can be modified. Its composition and thickness of layers are significantly influenced by the climatic conditions in the region where construction is underway. There are 2 main types of metal profile roofing:
- Cold Cold called the roof of metal, which is mounted on an unheated attic. They do not provide for thermal insulation, so they are cheaper. As a waterproofing they use low-cost materials, in particular roofing material. More simple in arrangement, cold roofs are used for the construction of seasonally used or garden houses.
- Warm Warm roofing is mounted if a living, heated attic is installed in the under-roof room. To avoid heat loss through a large area of the roof, in contact with atmospheric air, the roofing cake includes a layer of insulation, vapor barrier and vapor-permeable waterproofing.
Important! The roofs of any type of metal tiles can serve more than 25 years, provided proper installation, timely maintenance and proper operation. The composition of the pie of the roof, the desired sequence of layers and the selection of materials to be combined prolong the operation of the finishing coating, preventing corrosion and decay of the truss frame.
Thermal Insulation Requirements
The high resonating ability of metal tiles is a feature of the material that must be taken into account when making up the roofing pie. In order to reduce the noise caused by gusts of wind, rain or hail, a roof insulation with such a coating must also perform a noise insulation function. Therefore, the following requirements are imposed on it:
- Insulation should have a high noise absorption coefficient, not less than 0.5. Therefore, for thermal insulation metal does not use foam. Basalt fiber, glass wool, mineral wool has good sound-absorbing properties.
- Thermal insulation material must have a low modulus of elasticity. This indicator reflects the relationship between the density of insulation and the speed of propagation of sound waves in it.
- It is important to choose a resilient, well-preserving heat insulation that cannot be creased.
- Low hygroscopicity. Insulation with low hygroscopicity will not lose thermal insulation when wet, which will do a good job when leaks into the roof frame.
Consider that most thermal insulating materials lose their effectiveness when wet. Thermal insulation properties of insulation with an increase in humidity are reduced by more than half, therefore, in the roofing pie for metal tile they include reliable membrane waterproofing and vapor barrier.
