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, not rely at all on any of this and you must always seek your own professional advice from a skilled, experienced and fully qualified building surveyor.


I first wrote about the use of these foam products in December 2016.

Expanding foams in Listed Buildings

Anecdotal reports suggest that spray foams have been used in the UK for about 35 years, or thereabouts.   They are sold on the basis of offering one of two main purposes – thermal insulation to a pitched roof space or exposed wall, or perhaps for stabilisation for a failing roof covering that might be suffering, for example, from nail fatigue or frost damage and having some leaks.

In the last few years, these products have been increasingly sold and advertised widely on TV, online and using social media and there has been a recent boom in the industry development.  There is no actual independent science to show ‘before and after’ scenarios to prove, or disprove, the claims made for the products and neither does there seem to be any guidance on their installation requirements.   It is all very vague, which leads to no one really understanding what they are or whether they are any good or not.   The industry that sells and promotes the products try to emphasise the credentials, will refer to BBA (or other) certification and the alleged vapour permeability of ‘open cell’ foams but they won’t tell you about the damage that has been already caused by the previous use of foams or that they don’t provide any warranty on the consequential use of the product.

There are reports of massive scams, misselling and inappropriate installations and I have joined an industry-wide task group to investigate it.   There are about 35 people in the group ranging from UK Finance, RICS, Historic England, Historic Environment Scotland, leading mortgage lenders, the national mortgage valuation firms, academics, residential surveyors and contractors.  I have been asked to join the group to assist with the heritage sector.  It is actually a very interesting research project and it seems from the outset that no one really has a grasp on the science.  It is timely that we can now try to find out.  We need to understand the use of spray foams in far more technical detail and we specifically need to better understand the building pathology consequences of the foams that were installed many years ago.

If you are a building owner with the foam installed and you would be willing to talk to me and possibly let me come and see it then please do get in touch.

While the group has been tasked with trying to devise an inspection protocol that can be agreed by the surveying profession and by mortgage lenders, I am not yet convinced that this is even possible without very instrusive investigations and ‘opening-up’ of the roof structure and covering.   Simply looking at the underside of any roof with a spray foam installed is not sufficient.

These products should not be used at all on any historic roof structure.   It is extremely unlikely that Listed Building Consent would be granted for the use of spray foam insulation.   Always talk to your local Conservation Officer if you have spray foam in your roof now, or are considering buying a property where it is already installed.

As far as we know, the lifetime/equity release mortgage market has pulled out and are apparently refusing to offer loans on properties that have foam installed.   The main mortgage market apparently has a ‘silent policy’ on the issue and will rely on their valuer and/or surveyor for advice and reassurance.   As it looks like it is currently not possible for that reassurance to be provided, we are hearing reports of mortgages being refused.   The conversations within the cross-industry are continuing and there is no positive outcome to report yet.


Update..:  November 2022

This article from the Home Owners Alliance contains a useful summary and update and is worth reading..:

Home Owners Alliance article on spray foams

This article was published on the BBC News website..:

BBC News website article


Update – February 2023

We have started on a series of site investigations to see and assess the condition of ten roofs that have had closed cell foam installed.


The photos shown below are from a variety of unknown sources/buildings that have been given to me for the purposes of illustrating the damage that has been directly caused by the use of foam spray insulation products.


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 advice.