The foam insulation material used to insulate your roof, attic, floors or walls is open cell spray foam insulation which is a type of polyurethane composed of isocyanates and polyols. It can expand to over 200 times its size when sprayed, filling every available space.

It is impermeable to air and therfore gives high levels of airtightness. Open cell spray foam achieves low levels of thermal conductivity creating a stable temperature that can maintain a regulated temperatures, warm in the winter cool in the summer.

Open cell foam is semi-permeable allowing water vapour to escape preventing harmful damp and mould to build up while maintaining a continuous airtight seal.

If you have a roof that is not counter battened then you will be required to maintain a 50mm air gap between the insulation material and the roofing felt. This can be achieved by adding a breathable vent card between the rafter 50mm from the roofing felt and spraying on top of the cards.