Air barriers (otherwise known as vapour control layers) aren’t new but their use has become increasingly common as standards affecting new build have risen. Roofing upgrade work has also brought greater demand for energy efficiency in older buildings.
A new development by Klober is a combined reflective air barrier. This can be applied over ceilings of loft conversions and rooms in the roof or in cold roof situations. Just as importantly, Wallint® solar offers contractors the opportunity of additional work by making walls airtight, even in timber frame buildings. With a vapour resistance greater than 500 MNsg it provides the highest performance. You don’t need to understand what MNsg means other than to know that the British Standard Code of Practice for the design of ceiling airtightness in pitched roofs (BS9250) requires a minimum performance of just 250MNsg. In conjunction with specialist Klober airtightness tapes and sealants Wallint solar enables heat loss to be greatly reduced while during a building’s critical drying out period prevents large volumes of water vapour entering the roof space.
Where a non-reflective air barrier is preferred, Wallint 50 can be used as an alternative in just the same way. Both products couldn’t be easier to install. At either edge of the roof area you simply need to leave a 150mm overlap to allow the air barrier to be sealed to adjoining walls. Fixing to rafters/ceiling joists is achieved simply by using corrosion-resistant roofing staples. Laps are sealed using a tape such as Permo® TR and where pipes pass through the barrier you can make a perfectly airtight seal using a Klober Pipe Sealing Collar. For refurbs, the barrier is laid vertically, either from ridge to eaves or vice versa, allowing small sections of roof to be worked on without restricting other trades.