Not automatically. Government-commissioned modelling found low moisture risk for open-cell foam installed to the BS 5250:2021 standard, and high risk where foam is sprayed directly onto tiles or slates[1]. What matters is the type, where it is sprayed, the paperwork and the condition of the loft. Check those calmly before deciding anything, including removal.
On this page
Key facts
- BSR moisture modelling (Mar 2024): open-cell foam to BS 5250:2021 low risk; foam directly on tiles or slates high risk in every scenario[1]
- Government answer (Jun 2025): an installation meeting scheme standards would not be expected to need removal or to prevent a mortgage[2]
- PCA survey (May 2025, as reported): major works recommended in 27% of 500+ inspections, a sample of homes already under suspicion[3]
- The Building Safety Regulator said in May 2024 that the research is theoretical modelling of a finite set of scenarios[4]
- Spray foam is combustible (reaction-to-fire Class E), and RICS advises checking your buildings insurance[5]
Step by step
Step 1 of 4
What best describes your situation?
Find out which type you have and where it is sprayed
Open-cell foam is soft and closed-cell foam sets rigid[6]. What it is sprayed onto matters more: the modelling found high risk for foam directly on tiles or slates, and for open-cell foam on felt-type underlay with no vapour control layer (a membrane on the room side)[1]. How to tell what you have
Find the paperwork
Look for the contract, product approval, condensation risk assessment, photographs, moisture readings and any warranty[5]. If there is none, the industry consumer guide suggests asking the installer, the manufacturer or the Insulation Manufacturers Association, and otherwise a specialist surveyor[7]. What paperwork you should have
Look out for signs of moisture
The PCA says incorrectly installed foam can cause condensation leading to timber rot, mould and mildew, and rusting of metal parts[8]. Foam also hides the timbers and can hide leaks, so what you can see is only part of the picture[5]. Does spray foam cause condensation or rot?
Keep the roof watertight and the loft ventilated
The industry consumer guide advises fixing slipped tiles promptly and keeping ventilation adequate, such as extractor fans[7], and the Planning Portal says eaves ventilation must be kept clear[9]. See Hoping to keep the foam: why vents at the top would not fix filled eaves. Ventilation and moisture
Check fire safety around cables, lights and flues
One Kiwa product approval asks for 75 mm clearance around recessed lights, flues isolated with non-combustible insulation and 30-minute plasterboard in habitable rooms[10]. RICS advises checking with your buildings insurer because the foam is combustible[5]. Is spray foam a fire risk?
Decide on evidence whether removal makes sense
The government has said an installation meeting scheme standards would not be expected to need removal[2], while the PCA reported, via the press in May 2025, major works recommended in 27% of inspections of homes already under suspicion[3]. Trading Standards advises an independent report before agreeing to removal[11]. Do you need to remove spray foam?
What to do next
- Don't let a cold call or a single quote decide for you.
- If you plan to sell or remortgage, check lender criteria early, because positions differ.
- Keep any paperwork, photographs and notes of problems in one place.
- If you want independent evidence of what is in your loft, see the inspection below.
Check your loft once, calmly
If you'd rather know than wonder, an independent inspection records the foam type where possible, what it is sprayed onto, and moisture readings at points that can be reached, with photos.
Report within 48–72 hours of inspection. Independent: no installation, no removal, no referral commissions.
Travel included within about three hours of the North West; a fixed supplement further away, shown with your total before you book.
It records what can be seen and measured. It can't see timber under the foam, and it isn't a report for a lender.
Questions first? Call or WhatsApp 07349 718935 WhatsApp (opens in a new tab)
Case files like this
Anonymised inspections Jan has carried out. Every loft is different.
Tenants saw winter damp marks: foam bonded to the tiles, and timber up to 19.6% in summer
Liverpool · Recent inspection · Spray Foam Inspection
Closed-cell foam from 2017, bonded straight to the tiles with no membrane and no ventilation, above a let house with winter damp marks. Timbers read 13.6–19.6% in summer. If a sale or remortgage lies ahead, the report sees removal as the realistic long-term fix.
Read case file Worried about damp or condensationHoping to keep the foam: why vents at the top would not fix filled eaves
Rochdale · Recent inspection · Spray Foam Inspection
Open-cell foam from 2022, mostly on a breathable membrane, with the eaves filled. Nothing required removal now, but the loft air held 2.3 g/kg more water than outside, and timber in the foamed zone averaged 5.3 points wetter than timber outside it.
Read case file Is there spray foam in my loft?No spray foam found, but rafter after rafter carried marks consistent with condensation
East Hampshire · Recent inspection · Spray Foam Inspection
No spray foam anywhere reachable in the main loft, nor any sign of removal. But more than a dozen rafters carried the same two-part water mark, the eaves were open in seven places and packed in four, and a plate at the eaves had rusted.
Read case fileGo deeper: the original sources
3 original documents, each with a note on what it covers.
Questions people ask
Does spray foam rot roof timbers?
Not automatically; the risk depends on how the roof is built and how the foam was installed. Government-commissioned modelling found low risk for open-cell foam to BS 5250:2021 and high risk for foam directly on the roof covering[1], though the regulator stressed it is theoretical modelling[4]. The PCA says incorrectly installed foam can lead to rot[8].
Do I need to remove spray foam?
Sources
13 sources, numbered as cited in the text. Tap a footnote number to jump to its source.