FOR houses with the serious problem of failing wall ties one useful solution assists in both stabilising and insulating the walls.

This is an insulant that bonds the walls together but also has a much higher insulation value than the more commonly used injected cavity wall insulation materials.

Called polyurethane foam, it is also pumped into cavity walls, but at lower pressures to prevent stress on the walls. Once set the closed cell foam acts as a strong bonding agent.

The insulant is also commonly used for locking on roof tiles, when roof tile fixings have failed. A thick coating can impart high efficient insulation to the roof, reducing air leakage and draughts. Used also at rafter level a warm roof void can be created, obviating the need for air vents, pipe lagging and tank jackets.

The liquid polyurethane foam system is injected by specialist members of the British Urethane Foam Contractors Association into the cavity formed in a traditional masonry cavity wall.

Members of the British Urethane Foam Contractors Association agree to the Association's Code of Professional Practice. To find a local member contact the association at PO Box 12, Haslemere, Surrey, GU27 3AH, on (01428) 654011 or email info@bufca.col.uk