Is spray foam insulation worth it? As my old lecturer used to say, if it sounds too good to be true… it is probably a con!
Something we are seeing an increasing amount of recently is beautiful old roof spaces covered with white, spray foam insulation. There are many different types, some of which even claims to be breathable. With extravagant claims and promises of reducing your heating bills and protecting your home from water ingress, many a poor and vulnerable people are being conned into buying this horrible stuff. One thing we can all surely agree on is that the material changes the look of the building, so it requires listed building consent, and your conservation officer would never agree to this, but why not?? If its breathable, going to reduce emissions etc. then why would a conservation officer not allow it? Simple, it rots the adjacent timbers, changes the pathology and character of the building and can never be reversed without causing significant damage.
What about newer homes? What we have seen recently is that valuers will down value significantly properties that have been spray foamed so much making some un-mortgageable or putting the owners in a negative financial position. Timber is a natural material, it needs ventilation.
So what is spray foam insulation and who is behind this madness? Spray foam insulation is a liquid foam which is sprayed into position and sets into an insulating layer. It goes onto say that it can stop “Air Leakage”!!! Alarm bells ringing anyone. What do us weird old conservation guys bang on about all the time? BREATHABILITY. The chemical list to create this whipped cream is extensive, if there is a fire in your house then I would just start running and don’t stop until you’ve reached the coast. Similarly, according to the U.S. Environmental Protection Agency (EPA), “exposures to [spray foam insulation (SPF)’s] key ingredient, isocyanates, and other SPF chemicals in vapours, aerosols, and dust during and after installation can cause asthma, sensitization, lung damage, other respiratory and breathing problems, and skin and eye irritation.”
To summarise, the reason it is considered “insulating” is because it is closed cell, i.e. not vapour permeable. Old buildings need to “breathe”. When the property was built, the roof space would have been un-insulated thus allowing airflow between the rafters. Many mortgage providers will not lend on properties with this insulation and many RICS Registered Valuers will value a property at £0 as the risks are to great.
We advise all our clients who are buying a property that has been chemically sealed with spray foam insulation to look elsewhere. If you are considering spray foam insulation for your old house, then think again. There are sustainable, green and economical ways of insulating your homes, but this isn’t one of them. If you’ve had this work undertaken in your old, listed building without consent, get your cheque book out and pack your bags for a stay at her majesty’s pleasure.
As always, we love to hear from you. If we can help, we will, send us an email with photographs. Old buildings love to be treated well and nothing is a lost cause, as they say, trust the professionals, not the chemical cowboys offering miracles.