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Spray Foam Insulation FAQs
Open-cell and closed-cell foam — common questions, clearly answered
Spray foam made simple
All your spray foam questions in one place
Spray foam is powerful — but it needs to be applied in the right places, by trained installers, using SEAI-accepted systems. This page answers the most common questions we get from homeowners, builders and farmers about where and how we use spray foam insulation.
What’s the difference between open-cell and closed-cell spray foam?
Open-cell foam is breathable and soft — ideal for sloped attic ceilings where ventilation is present. Closed-cell foam is dense, vapour-resistant and ideal for underfloors, metal roofs, farm sheds and commercial units.
Can spray foam be used on all types of roofs?
No — spray foam must only be applied to ventilated roof structures or approved substrates. We do not apply foam directly to non-breathable felt or sealed roofs without proper venting.
Is spray foam SEAI grant approved?
Yes — but only certain applications are eligible. We only use SEAI-accepted products and follow proper system specs. We’ll confirm grant eligibility during your survey.
Do you install spray foam in commercial or farm buildings?
Yes — we use closed-cell foam for agricultural sheds, concrete warehouse ceilings, milking parlours, and other commercial roof decks where temperature and condensation control are critical.
Can spray foam cause condensation or rot?
Not when installed correctly. We assess ventilation, moisture risk and substrate. Open-cell foam is breathable and used where airflow is maintained. Closed-cell foam must not trap moisture behind surfaces.
How long does spray foam take to install?
Most attic or roof slope jobs take 2–4 hours. Large commercial installs or crawlspace projects may take a day. We’ll confirm duration at survey.
Is it safe to stay in the house during install?
For domestic attic installs — usually yes. For larger or enclosed areas, you may need to vacate during curing. We’ll advise clearly when booking.
How long does spray foam last?
When installed properly, spray foam lasts 25+ years with no sagging or breakdown. It also helps reduce draughts and noise in key areas.
Will I get documentation after install?
Yes — you’ll receive a full handover pack with photos, system details, product data sheet and warranty certificate.
Can spray foam improve airtightness?
Yes — spray foam is often used to help meet airtightness targets in deep retrofits or passive builds. Closed-cell foam provides excellent air sealing when used appropriately.
Still have questions?
Book a free survey and we’ll confirm whether spray foam is suitable for your roof, attic, farm building or commercial space — or suggest alternatives.