Closed cell foam trapping condensation against roof felt
Why it happens here
Closed cell foam is impermeable, so when it is sprayed directly onto roof felt it seals the roof and stops it breathing. In Stirchley's damp climate, moisture from inside the house rises into the loft and condenses on the cold felt. Over time this leads to wet timbers and rot.
Our approach
We remove the foam with dry ice blasting, check the timbers for rot, and fit ventilation trays or breathable membrane to restore airflow. We also advise on breathable loft insulation that will not trap moisture in the same way.