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Building Products April 2017

ICYNENE | INSULATION AND ACOUSTICS APRIL 2017 | BUILDING PRODUCTS 31 Doing most of the work themselves to keep costs under control they quickly recognised some of the challenges they faced in bringing the building up to habitable standards in this exposed location. Son James Brakewell takes up the story: “The biggest problem we faced with the barn conversion was insulation. It’s a huge building measuring 19m x 10m with an eaves height of 10m. There are old cattle byres on the ground floor with a two-story overshot barn on top, all built of local Burlington stone” At the start of the conversion, an internal frame of timber studwork was installed, set 50mm off the external walls. Conventional rigid board insulation was considered but quickly rejected on the grounds of speed of installation and poor air tightness performance. James continued: “The main issue with insulation is air tightness. Most heat is lost from a building through air leakage and we knew we couldn’t seal the building adequately with rigid board material. The wind would always find a way through” he said. “What’s more, cutting and fitting boards to the studwork and beneath the roof would take weeks of work. We needed a system that would be both quicker to fit and give us better performance.” James looked at alternatives and contacted local contractor Greentherm Solutions, a company that specialises in spray applied insulation, using Icynene, a system originally developed by a Canadian company. It is a water blown breathable foam that expands 100-fold when applied and seals every little crack, joint and service hole completely. Greentherm sprayed Icynene between the stud wall frame and directly on to the exposed stone walls creating a homogeneous and un-interrupted blanket of insulation, 125mm thick. The roof structure was treated similarly, spraying directly on to the breathable underfelts. As Icynene is “vapour open” there is no need to maintain an air gap above the insulation. To prevent noise transmission between the dwellings, Icynene was also used as cavity fill insulation in the blockwork party walls. According to the manufacturer, because Icynene has a soft, yielding texture and open, cellular composition, it provides outstanding insulation performance yet still allows the building to breathe naturally, preventing the build-up of potentially damaging condensation. “The whole spraying process took less than a day and a half to complete rather than the three and a half weeks it would have taken to insulate with rigid boards” said James. Costs were broadly similar for both insulation methods but speed of installation and performance were in Icynene’s favour “you simply cannot fit any other kind of insulation faster” he concluded. Throughout the process, Local Authority Building Control was kept informed and was fully supportive of the process use. www.icynene.co.uk


Building Products April 2017
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