To insulate lofts we use an open blown method. This makes it easy to add cellulose fibre to any depth as required. Building regulations specify a minimum of 250mm, but the blown installation system means it is often cost effective to install to greater depths.
To insulate pitched roofs we use the ‘dry injection’ method. As when insulating walls, we cut a hole in the covering board or membrane and blow insulation into the void behind. Holes are patched once each cavity is filled.
Until recently, many houses we built with a bitumen felt underneath the roof tiles. This is impermeable to vapour. It is essential to leave an air gap between the insulation and felt to prevent condensation problems. Modern roofing felts are normally ‘breathable’ and do not require an air gap. With details of your roof construction, we can assess whether insulation is possible.
Flat roofs always have an impermeable covering, so an air gap must be left above the insulation. In many cases flat roofs lack access to create this space. We assess each customers needs on a case-by-base basis, so do get in touch to discuss your project.