During the construction of a country house or cottage, an important stage is the construction of a roof, on which the safety and comfort of living in this building directly depends. This article will consider such an important aspect of roof construction as insulation - the roof must have reliable and high-quality hydro, steam and thermal insulation, which will allow it to last as long and efficiently as possible.
When installing a roofing pie, it is laid out of several layers, each of which is vital for the reliability and efficiency of the roof:
- Thermal insulation that allows you to keep heat under the roof in winter and not let it through outside in summer;
- Waterproofing designed to prevent the thermal insulation layer from getting wet by atmospheric moisture;
- Vapor barrier that protects thermal insulation from the action of water vapor;
- Ventilation of the under-roof space, providing the removal of water vapor, preventing their condensation on the insulation.
Let's take a closer look at the main layers of roof insulation.
Roof waterproofing
The roof waterproofing device is the most important element of the roofing pie, which determines the performance of the building, which depends on the quality and reliability of its roof.
When choosing materials for roof waterproofing, you should pay special attention to the cost of installing the roofing and its suitability for subsequent repairs.
Roof waterproofing, which is the most important stage in the construction of the roof, is designed to prevent moisture from entering the interior of the building into the internal layers of thermal insulation, which helps to avoid heat loss by the roof structure, maintain the effectiveness of the insulation material and avoid the formation of condensate in it.
When installing waterproofing roofing materials, all rules and regulations for roofing work should be observed.
In many regions, temperature fluctuations quite often occur, leading to fairly rapid wear of the enclosing structures of residential and industrial buildings and structures. It is the roofs that are most susceptible to such wear.
Roofing roll materials, as well as roofing waterproofing mastic, make it possible to achieve water tightness even at very small angles of roof inclination, while the maximum recommended angle is about 50º.
Data roof materials can be laid on any solid base (concrete, wood, etc.).
According to the method of laying rolled materials, roof waterproofing can be divided into several varieties:
- Waterproofing glued;
- Waterproofing, for which hot roofing waterproofing mastic is used;
- Waterproofing, in which polymer, rubber-bitumen or bitumen-polymer mastic is used for roof waterproofing;
- Welded waterproofing;
- Based on modified and oxidized bitumen;
- Waterproofing applied by a hot fire method using a gas burner;
- Fireless hot method using infrared radiation;
- Fireless cold method by dissolving a thickened bituminous layer;
- Waterproofing with an adhesive layer, in which the materials are provided with a protective coating of silicone film or paper on the inside, which is removed, after which the roll is rolled out on a pre-primed surface.
The most common method is the long-known method of continuous gluing of materials to the base of the roof. In addition, in some cases it is recommended to use partial sizing.
This method eliminates the possibility of excess pressure due to the air gap between the base and the waterproofing layer, which can communicate with the outside air through the roof contour or exhaust vents.
This method of performing waterproofing is called a "breathing" roof. . It allows not only to prevent the occurrence of blisters, but also to increase the efficiency of removing moisture from the material used in the manufacture of the base.
Useful: in the case of a fixed section of the air layer, special powders applied to the waterproofing roll material during the production process can increase the amount of moisture removed.
The device of "breathing" waterproofing also completely eliminates the possibility of its rupture at the joints or cracks in the base, since their deformations are not transferred to the roof carpet.
thermal insulation
When erecting a roof, it is necessary to solve a variety of tasks related to both engineering and aesthetic and architectural issues.
In addition to choosing the type of roof construction, the angles of inclination of the slopes and the material for finishing, it is also important to clarify the requirements for various thermal parameters of the roof.
This is necessary in order to determine whether roofing insulation needs to use a layer of insulation, what humidity is acceptable for the roof structure, whether roof heating equipment is needed, etc.
The thermophysical parameters of roofing have a significant impact on its overall vulnerability.
Absorbed by the surface of the roofing in the summer, it sinks down into the supporting structure of the roof, and in winter it is transferred from it upward, causing in both cases certain temperature deformations that differ in different layers of the roofing.
Important: the roof layer is more in need of seams that relieve thermal stress than the supporting structure with high-quality thermal insulation.
A sharp drop in temperature can cause breaks in a rather fragile roofing layer, so it is necessary to use expansion joints located as often as possible.
In addition, the load-bearing structure should be designed so that it can withstand the loads of wind and snow cover, as well as people who can climb on the roof.
Wind and snow loads on the roof are calculated in accordance with the climatic zone, wind rose and roof slope angle. In Russia, the load of snow cover varies depending on the terrain, taking values from 25 to 250 kg / m for the horizontal projection of the roof.2.
In Moscow, it is approximately 60 kg with a roof slope of 35 degrees, so in most cases mechanical cleaning is required at least three times during the winter.
vapor barrier
Depending on the type of roof structure, as well as the type of attic space and the load on it, solutions should also be selected to prevent the condensation of water vapor in the roof coverings. The presence of an attic allows the use of various methods of dealing with condensate.
The vapor barrier barrier is arranged under a layer of plaster on the ceiling on the warm side of the attic, and a layer of insulation is already laid under the vapor barrier.
In order to remove the steam that has passed through the vapor barrier, ventilation holes in the ridges and roof overhangs, exhaust pipes and other devices are used.
Steam-permeable, vapor-diffusion and vapor barrier films made on the basis of polypropylene and polyethylene, as well as special designs on ridge elements, are the most important element of the roofing of an attic or attic room.
Important: when performing vapor barrier of heat-insulating material slabs, one should not allow the installation of two layers of vapor barrier, one of which is arranged on the carrier plate, and the other is the roof covering made on the insulation.
Ventilated aprons prevent the condensation of water vapor in the space between the vapor barrier layers thanks to air channels protected from snow and rain, which allow water vapor and air masses collected in the under-roof space to be brought out under the action of solar heating of the roof surface.
Thus, roof ventilation will not be a problem for the owners.
Roof insulation
In the case of pitched roof insulation, the laying of the material can be done in different ways:
- The easiest way is to install insulation between the rafters, when the insulation material is laid horizontally, avoiding sagging that prevents effective air circulation in the under-roof space;
- When insulating the roof between the rafters, the material is placed in two layers, one of which is laid between the rafters, and the second - above the rafters.
- Laying insulation on the rafters is done by placing an insulating layer over the supporting roof system, preventing harmful atmospheric effects.
- Insulation under rafters when mineral fiber panels are used for insulation.
When using each of the methods, you should carefully check the condition of all wooden elements of the roof structure for the absence of damage by pests, the moves of which can be detected by heating.
In addition, the moisture content of wood should not exceed 18%. If necessary, damaged elements are replaced, after which the wooden elements are treated with special compounds based on artificial resins.
Roof insulation is the most important stage in the construction of any residential building and structure, since the efficiency and reliability of the roof depends on the quality of its implementation, which directly affects the performance of the building and the comfort of living or being in it, as well as the service life of the roof without unplanned maintenance or repair.
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