Spray-foam insulation makes homes unable to be mortgaged
theguardian.com
Spray-foam insulation makes homes unable to be mortgaged
1–10 of 133 posts
Re: Spray-foam insulation makes homes unable to be mortgaged
#2Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
Re: Spray-foam insulation makes homes unable to be mortgaged
#3Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
I assume that it's due to the expanding nature of the foam -- they are afraid that the foam might continue to push against the roof timber and crack it I think
Re: Spray-foam insulation makes homes unable to be mortgaged
#4Re: Spray-foam insulation makes homes unable to be mortgaged
#5Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
From the article:
> Executive found that condensation could cause 25% of roof timber to decay within five years if spray foam is applied directly to roof tiles, or certain underlays. The general risks increase the further north the property is, because of colder climates.
Most houses in the UK will have a timber frame, condensation will cause the wood to rot.
Re: Spray-foam insulation makes homes unable to be mortgaged
#6Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
I assume that it's due to the expanding nature of the foam -- they are afraid that the foam might continue to push against the roof timber and crack it I think
No it's about trapping moisture.
>A report published in March by the government’s Health and Safety Executive found that condensation could cause 25% of roof timber to decay within five years if spray foam is applied directly to roof tiles, or certain underlays. The general risks increase the further north the property is, because of colder climates.
Re: Spray-foam insulation makes homes unable to be mortgaged
#7Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
Iirc using closed cell foam, or open cell badly installed, either will stop moisture getting out, causing damp amongst other issues.
Re: Spray-foam insulation makes homes unable to be mortgaged
#8Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
It’s basically the same thing as wrapping the wood into a plastic bag. When water condenses inside the plastic it has no way of escaping and starts to rot/mold the wood.
When using any type of insulation in places where temperatures can vary and humidity can get high you should always ensure the wooden parts have enough room to breathe (e.g. 10cm of empty space above them if the insulation is at the bottom).
Re: Spray-foam insulation makes homes unable to be mortgaged
#9Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
I assume that it's due to the expanding nature of the foam -- they are afraid that the foam might continue to push against the roof timber and crack it I think
No they specifically mentioned condensation and how it affects properties in colder climates more. I think they're afraid the improperly installed insulation will allow condensation to build up below the roof timber which will cause the timber to become wet and degrade.
Re: Spray-foam insulation makes homes unable to be mortgaged
#10Can someone explain the mechanism how the foam can damage the building? I didn’t quite get it from the article.
It traps moisture which leads to mold and for wood to rot. You nearly never want to install insulation without a vapor barrier. And especially not with spray foam. People do it because it’s cheap to do. You only have to punch a small hole in the wall and spray into it.
Also if you want insulate an old house consider you should install an HVAC system so that you are properly venting. Old houses self ventilate because they’re so loose compared to modern homes with tight envelopes.