According to experts, about 15% of heat can escape through the roof and attic space of a residential building, even with basic insulation. If you do not use insulation at all, then the remaining cold bridges in winter will neutralize the effect of the heating systems. At the same time, modern truss structures and roofing provide extensive opportunities for improving the energy efficiency of the building. A properly arranged warm roof will provide not only microclimatic comfort, but also extend the service life of the attic space materials.
Insulated roof design features
In its purest form, an ordinary pitched roof is a load-bearing frame formed by beams, mauerlat, support posts and battens on which the roof is laid. The configurations of the truss system may vary, but the most important thing is that even when assembled and in operation, they can be insulated. Thermally insulatedthe roof structure is distinguished by the presence of several layers of insulation in the transition areas. The lowest level is the ceiling that separates the attic from the living space. This is followed by direct insulation of the slopes from the back sides and in the layer between the crate and the roofing. In addition, the device of a warm roof provides for the presence of technological ventilation zones. They may have different designs, but the task of ventilation gaps is the same - to exclude the accumulation of condensate in the under-roof and attic space.
Selection of thermal insulation material
The layout of the insulation will largely determine the effectiveness of the thermal barrier, but if the wrong material was initially used, then the highest quality installation will not solve the problem of heat saving. Roofers recommend paying attention to the following types of heat insulators:
- Glass wool is a cheap and easy-to-install material with acceptable insulation performance. Its strength will be the complete exclusion of biological destruction processes, and its weakness will be the loss of insulating qualities after wetting.
- Bas alt slab. Also a moisture-sensitive insulator, but it is fire resistant, which is also important for the site in question.
- Mineral wool. A variety of structural designs and durability can be put in a number of the main advantages of this insulation. A warm roof with mineral wool retains its characteristics for 50 years. But this material should also be protected fromany contact with moisture.
- Polyfoam. Another option for budget insulation, which has decent insulating properties, but a lot of design flaws. Styrofoam should only be used if there is good mechanical protection.
- Polyurethane foam. Foam insulation with low thermal conductivity. It is difficult to do without it when spot sealing hard-to-reach cracks and gaps.
Installation of heat insulator
The insulation is built into the design of the slopes from the inside. As a rule, the form of heat insulator for the roof is a slab or thick roll material such as mats. Laying is carried out on a prepared surface with profile bearing strips. On the beams of the truss system, a crate of wooden bars is mounted, to which a heat insulator is subsequently fixed. Fastening can be done with mounting brackets, screws or glue. This is not fundamentally important, since the slab or mats must be covered with a counter-lattice, the planks of which are nailed to the warm roof rafters. Insulation is carried out according to the method of continuous sheathing with complete sealing. Slots, technical gaps and joints are sealed with either moisture-resistant sealants or the aforementioned polyurethane foam. For greater structural reliability, it is advisable to continue the outer crate up to the Mauerlat beams, where the walls of the house begin.
Laying hydro and vapor barrier
Review of heat insulators showed that without a reliableprotection from moisture, the material simply gets wet and ceases to perform its main function. Therefore, the next step should take care of hydro and vapor barrier. Membrane film materials are used for this, for fastening of which a supporting structure is not required. In particular, for arranging a warm roof, Uniflex, Linokrom and Technoelast waterproofers are recommended. In some modifications, they also perform the functions of a vapor barrier. Laying is carried out on a surface with a fixed heat insulator by gluing. There are self-adhesive films, but universal building compounds can also be used to fix insulators with a water-repellent effect. Without fail, the film is closed from the outside with planks in increments of 20-30 cm.
Creating a ventilated gap
The removal of condensate from under the roof space is not only a measure to protect the heat insulator. The wooden truss system is also sensitive to dampness, and if you do not think through the air circulation channels, then in the very first months of operation, you can find pockets of fungus and mold development. How to make a warm roof with a ventilation gap? The best option is to use perforated cornices on overhangs. These are special plastic boxes that are installed along the edges of the slopes, forming a buffer zone with air heat exchange. This will ensure effective ventilation of the space from the bottom without the risk of precipitation.
Choosing a warm roof
Roof decking can have different heat-savingquality. The roof in this sense plays a decisive role, but it is far from always possible in principle to use a dense cover with good sealing. For example, shingles, due to their severity, are contraindicated for installation on weak truss systems of many private houses. The output will be a multi-level warm roof - a roof, the upper level of which is formed by several technological layers. The first layer along the slopes can be laid out with a vapor barrier, and then wind and water insulators will follow. The task of thermal insulation in this part is not the most important, since the already mounted rear skin will be responsible for the regulation of heat flows. In the structure of the roofing system, it is important to provide protection from physical influences, including wind, precipitation, snow, etc.
Floor insulation
The main barrier to the cold outside from the top of the house is the interfloor overlap that separates the attic from the lower rooms. In this zone, there are much more opportunities for warming. They should be used to the maximum benefit. A layer of expanded clay or sawdust can be poured into the very niche of the warm roof overlap. These are loose heat insulators, the advantages of which include environmental friendliness and affordable cost. However, expanded clay gives a large load by weight, and sawdust are combustible materials and are prone to biological damage. Well, then a horizontal crate is already mounted on the surface of the ceiling, in the cells of which heat-insulating plates are also laid. If the design allows for height, then you canperform a double crate with the arrangement of different heaters with fibers crosswise.
Features of flat roof insulation
In this case, the emphasis is on the use of loose heat insulators and liquid waterproofing. As for the first, it should not be expanded clay with sawdust, but special lightweight materials like expanded polystyrene crumbs, penoizol or foam glass. But the main feature lies in the design solution - the creation of a special hatch under the roofing in the form of a niche 15-20 cm thick. This space is completely covered with an insulator. Outside, the flat structure of the warm roof is covered with molten bitumen using a gas burner. A fully sealed roof deck is formed to provide hydro and vapor barrier.
Conclusion
When choosing a roof insulation method, one should be guided by a simple rule - stable moisture removal with maximum heat retention. It is important to strike a balance between the ventilation ducts of a warm roof and its sealing. And at each stage, one should remember about the bearing potential of the truss system. Overloading with additional layers of heat and hydro barriers can shorten the life of a timber roof structure. Therefore, a balance is also maintained in the technical and physical parameters of the selected materials with consumable fasteners.
