Foam shrinkage leaving gaps at the rafters
Why it happens here
Most foam in Bulk's Victorian terraces was sprayed onto cold timber in poorly ventilated lofts. As it cures and ages it contracts, pulling away from the rafters. The gap that opens up lets warm, moist air reach the cold roof surface, where it condenses.
Our approach
We cut the foam back completely rather than patching it, because patches fail in the same way. Once the timbers are exposed we check for rot and clear the eaves ventilation, so the loft can manage moisture properly after we leave.