This is not an exhaustive or a complete subject. It is likely to change over time, with edits, additions and deletions, and is simply a collection of my thoughts based on many years of experience. You should follow your instincts, and you must always seek your own professional advice.
The topic of spray foam insulation in roofs has generally been a lot quieter within the surveying profession for several months. I have written about it here previously. However, within the last month or so, I have received enquiries about it and have done four invasive inspections – all on roofs of Listed Buildings.
None of the cases had Listed Building Consent for the initial installation, but all will now require Consent for the removal.
In each case, the exposure of the old closed cell foam produced evidence of severe wet rot in the upper part of the rafters. This is the part of the rafter that can’t be seen during a normal building survey. It is the part facing the roof covering and hidden from view.
The roofs will need to be stripped, with most likely a 0% salvage of the slates/tiles. The exposed roof structure will then need to be reassessed to decide whether any rafter need to be replaced.
As it currently stands, we understand that properties with spray foam in the roof (whether closed cell or the more modern open cell variety) are not mortgageable. Lenders are unwilling to accept the risk.
Surveyors undertaking property inspections who find spray foam should be very cautious and should be advising their clients of the risks and the current situation.
If you are concerned about spray foam insulation in your house, or you are trying to buy a house where it has been seen, please do get in touch with me duncan@listedbuildingsurveys.co.uk
Disclaimer: Anything posted in this Blog is for general information only and it is not in any way intended to provide any advice, legal or otherwise, on any general or specific matter that you can rely on. You should always seek your own legal and surveying advice.