Spray foam
Spray foam attic insulation
Spray foam on the underside of a roof can block the cross-ventilation that keeps roof timbers sound, and a valuer may mark a house down for it. SEAI's grant paperwork asks the contractor outright whether spray foam was used.
It's sold hard in Ireland. Here's what to know before anyone sprays your roof.
Free, no obligation. One SEAI-registered contractor prices it, not five.
- €2,000SEAI attic grant for a detached house
- €2,500at the higher rate
- €300 to €600typically left to pay on a semi-D
- 300 mmof wool: what SEAI's standard takes
The risks
What can go wrong
- Ventilation. A cold roof needs air moving under the felt. Foam sprayed between the rafters can stop it.
- Timbers. Without that air, condensation can build up; SEAI's standard warns that long-term condensation in a roof space can rot the structural timbers.
- Resale. Valuers can take the view that spray foam materially reduces what a house is worth.
The grant
Spray foam and SEAI
SEAI's Declaration of Works for roof insulation, the form the contractor signs for your claim, has a line asking whether spray foam was used for the roof or ceiling. Whatever is used has to meet SEAI's standard: CE-marked or Agrément-certified, suitable for Irish conditions, reaching the U-value, and leaving the roof ventilated. Ask the contractor, in writing, whether their product and method qualify before you go ahead.
If it's already there
Buying a house with spray foam
Our advice: find out who installed it and whether they were SEAI-approved, and have the roof checked for either a ventilated cold roof or a warm roof with a vapour control layer. Open-cell foam is the more breathable type.
The usual route
What most attics get instead
Wool to 300 mm on the attic floor, with the eaves open. It's cheaper, the roof stays ventilated, and it's what most grant-funded attics get. See how thick.
Grant check
Your attic grant and what's left to pay
Two taps: your home, and which rate fits you. The answer is SEAI's fixed grant and its own median cost for the job.
Your SEAI attic insulation grant
€1,500
- SEAI median cost, Jan to Jun 2026
- €2,101
- Left to pay at the median
- €601
SEAI's fixed grant for a semi-d or end of terrace at the standard rate is €1,500. SEAI's median cost for attic insulation on a semi-d or end of terrace from January to June 2026 was €2,101. €2,101 less €1,500 leaves about €601. Our sum; your quote can be higher or lower.
Send this for a real priceHow this is worked out
The grant is SEAI's fixed amount for that home type and rate, as Citizens Information lists it. The median cost is SEAI's own figure from grant-funded attic jobs completed between January and June 2026; the PDF doesn't say whether VAT is in. Left to pay is the median less the grant, our sum. The home must have been built and lived in before 2011, the contractor must be on SEAI's register, and SEAI must approve the grant before work starts. It's an estimate, never a quote.
Your grant
Your attic grant and a price, in 4 taps
Tap your home, when it was built, what's in the attic now and who you are. Then leave your number and one SEAI-registered insulation contractor who covers your area rings you to look at the attic and price it in writing.
FAQ
Questions people ask
Is spray foam insulation bad for an attic?
It can be, if it blocks the roof's ventilation. It can stop the cross-ventilation roof timbers need, and it can reduce a house's value.
Can I get the SEAI grant for spray foam?
The product and method must meet SEAI's standard and keep the roof ventilated, and the contractor declares whether spray foam was used. Ask for confirmation in writing first.
Can spray foam be removed?
Yes, but it's slow and costly, because it sticks to the timbers and felt.
Keep reading
Related guides
- How thick should attic insulation be?300 mm, 200 mm, blown wool or boards: what reaches SEAI's standard.
- Roof and rafter insulation grantRafters, rooms in the roof and flat roof extensions: the whole-roof rule.
- Attic insulation costSEAI's median cost by home type, before and after the grant.
- Attic hatch insulationWhy the hatch matters, and what SEAI makes the contractor fit.