Almost 40 firms banned from installing UK insulation amid botched jobs outcry

Spray-foam insulation has been found to cause 25% of roof timber to decay within five years if applied directly to roof tiles. Photograph: Danielle Amy/The Guardian

Almost 40 building companies have been blocked by the government from installing insulation amid a growing outcry over the profusion of botched jobs across the UK.

Ministers also announced that any homes found to have received botched insulation would have the issues put right by the installer responsible at no extra cost to the homeowner.