Rafter insulation is an ideal solution when you want to insulate the roof without renovating the attic. Shielded from the outside, the roof truss is protected from changes in ambient temperature, improving the energy balance of the building. With this method, all work can be done from the outside.
This method has many advantages over traditional roof thermal insulation technologies: not only does it reduce the heat loss of the building, but also protects the roof structure. In addition, it gives more options for the arrangement of the attic and does not further reduce its height.
For structural reasons, roof over-rafter insulation is possible for sloping roof structures, where the angle of inclination is greater than 20°. PIR boards are most often used for insulation by this method, but both rock wool and wood wool have a number of technical parameters that determine their thermal insulation efficiency.
Screws for roofing insulation
Correct installation of the roofing insulation depends on the proper selection of screws. Klimas Wkręt-met offer includes carpentry screws WKPC, which are dedicated to the installation of the roofing insulation. Keep in mind that the material between the structure and the roofing will carry a lot of load, so its proper fastening is crucial for the safety of the structure. The WKPC roofing insulation screws have been equipped with a double thread, which makes it easier to catch the wood in the first step of screwing. This installation convenience significantly affects the speed of work. The screws have been equipped with a reaming cutter, a proprietary solution introduced by Klimas Wkręt-met, which effectively reduces resistance during screwing. Together with the cutting notches on the thread, it allows a 20% reduction in resistance during screwing.
The key solution of WKPC screws is the additional thread under the head. It is he who ensures stable fixing of counter-battens and transfers loads directly to the rafters, thus relieving pressure on the insulation and protecting it from damage. It is worth remembering that when installing rafter insulation, counter-battens with a thickness of min. 4cm.
How do you properly make a roofing insulation?
The selection of the right carpentry screws is of utmost importance in the proper execution of the roofing insulation. Standard installation requires screws to be installed both at 90 degrees and at an angle of 60-67 degrees, according to insulation manufacturers’ recommendations. When screwing at a 90-degree angle, the length of the fastener should be determined by the sum of the thickness of the materials to be joined, such as counter-battens, insulation sometimes additional boarding, and the required thread length. In the case of installation at an angle, screws should be selected with a longer length depending on the angle of screwing. Typically, the screws should be 10-15% longer than the thickness of the materials to be joined.