Twistfix

Guide to Fixing Pitched Warm Roof Insulation

Successfully fixing pitched warm roof insulation involves installing and securing the insulating material above the rafters using counter-battens structurally connected to the roofing frame by helical fixings. A common problem of the fastening process concerns imprecise nailing when driving a fastener into narrow rafters concealed beneath a thick blanket of insulation, causing timbers to split. 


Thor Helical manufactures an easy-to-use fastening system that offers the most reliable solution to these practical difficulties. Thors' innovative WRBF tool aligns and guides its Super 7 warm roof fixings, to the central portion of the counter-batten to rafter arrangement to conform to edge distancing codes and prevent the wood from splitting, thus improving build quality. The guide tool's profiled base fits 38mm and 50mm wide counter-battens. 


Stainless steel, a material renowned for its strength and resistance to corrosion, is used to create Super 7 warm roof nails. The components feature a patented precision helix, which rotates the fixing as it drives in. This innovative corkscrewing action prevents any splitting or bouncing of timbers, providing excellent holding power and maximising resistance to bending. Exceptionally versatile, roofing contractors can use these corrosion-resistant fasteners with all significant brands of insulation boards, including Celotex, Kingspan and Eco-Therm. 


Compared to standard 6mm helical nails, such as Inskew 600, Super 7 warm roof fixings have a 20% greater cross-sectional area. The additional material increases performance and stiffness, reduces the fixings required, lowers cold bridging potential, and offers tremendous cost and working time savings.  When expertly fixed, the over-rafter assembly will resist sliding and wind loads and not compress the intervening layer of insulation, resulting in the insulation's efficiency and performance combined with exceptional structural integrity.  


Super 7 warm roof fasteners have undergone extensive independent testing, repeatedly proving that they fully comply with the NHBC's exacting technical requirements. Calculating the correct size and quantity of Super 7 fixings for any given project is simple with HeliCalc. This accurate calculation tool is freely available to use on the Twistfix  website.  


A design method approved by the BRE, HeliCalc, can be used to provide details about the resistance of Super 7 warm roof nails to applied wind loads and bending moments. In addition, using HeliCalc is invaluable in establishing a project's warm roof fixing specification and ensuring that a proposed project complies with building codes.  


Here at Twistfix, you can purchase Thor Helical Super 7 warm roof insulation fixings in packs of 50 at the most competitive price. A comprehensive range of sizes is available from 130mm to 240mm in increments of 10mm. Please visit the the product page on our website for more details and, as always, do not hesitate to contact our expert technical team if you need further information or advice.  

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