Open-cell spray foam removal is usually quicker than removing rigid foam, because soft foam cuts easily and tends to come away from felt and timber more readily. The main concern with open-cell foam is moisture: it can let damp air reach the cold roof underside, so we remove it carefully, clean the timbers back and moisture-check them before recommending re-insulation.
What is open-cell spray foam?
Open-cell foam is a lighter, low-density polyurethane foam. Its cells are not sealed, so it stays soft and flexible and lets water vapour pass through it. It was often sold as a “breathable” option and applied thickly between the rafters to insulate the roof slope rather than the loft floor. It does not grip as hard as closed-cell foam, but it still sticks to felt and timber and it hides them completely.
How to tell if you have open-cell foam
- Soft to touchIt squashes easily under your thumb and slowly springs back.
- Light and spongyIt looks and feels a bit like a bath sponge or bread.
- Thick layerIt often fills the whole rafter depth or bulges past it.
- Matt surfacePale, matt and easily marked or torn, rather than glossy and hard.
If yours is hard and barely dents, read about closed-cell foam removal instead. Paperwork from the installer can also confirm the type.
Why moisture matters with open-cell foam
In winter the house produces a lot of warm, damp air from cooking, washing and breathing. Some of that rises into the loft. Because open-cell foam is vapour-open, that air can move through the foam to the cold underside of the roof, where it may condense on the felt or timber. In a well-ventilated roof this can dry out. Where foam has also blocked the eaves, or the felt is an old non-breathable type, moisture can build up with nowhere to go.
Signs of this include dark staining on timber at the foam edges, a damp or musty smell, wet patches on the foam surface, drips onto stored items, or mould spots on the loft hatch and ceiling below. None of these prove there is decay, but they are good reasons to have the foam taken off and the timbers checked. Our spray foam problems guide explains condensation and ventilation in more detail.
Signs you need open-cell foam removed
- A lender, valuer or surveyor has asked for removal or a specialist report.
- You notice damp smells, staining, or condensation in the loft.
- The foam is sagging, splitting or falling away in places.
- You want the roof timbers visible before selling or carrying out roof work.
- You would rather insulate at loft-floor level and keep the roof cold and ventilated.
How we remove open-cell foam
- Talk it through. We ask about the house, the foam, any damp or smells you have noticed, and whether a sale or remortgage is waiting.
- Visit the loft. We confirm the foam type, look at thickness and coverage, check eaves ventilation and note any visible damp.
- Quote in writing. You get a written quote and a plain explanation of how long the work is likely to take.
- Protect the house. We sheet the landing and hatch area and keep the loft as the working zone.
- Cut out the bulk. Soft foam is cut out between rafters in large sections, which is where open-cell removal saves time.
- Clean back gently. The remaining layer is scraped off timbers and felt by hand, taking care with fragile or damp felt.
- Bag and remove. Open-cell foam is bulky, so there are usually plenty of bags; all of it is taken away for proper disposal.
- Moisture checks and report. Timbers are inspected and moisture-checked, and you receive a written report with photos.
This follows the same careful method as all our loft spray foam removal work, adapted to soft foam.
Open-cell foam in Liverpool and Merseyside houses
Liverpool’s damp, mild climate and the many older homes with limited loft ventilation mean we pay close attention to condensation. Semis and detached houses in places such as Woolton and Childwall often have larger lofts where thick open-cell foam was used to insulate the roof slope instead of the floor. Coastal homes in Formby and Crosby face wind-driven rain, which makes dry, well-ventilated roof timbers even more important. Wherever the house is, our spray foam insulation removal across Merseyside follows the same steps.
What affects the cost of open-cell removal?
- Roof area and foam thickness, since thick open-cell foam produces a lot of waste to bag and remove.
- Loft access and headroom.
- Whether the felt behind is fragile or damp and needs extra care.
- Whether old mineral wool or debris on the loft floor needs clearing too.
- Whether you want the loft re-insulated as part of the same job.
Open-cell jobs are often quicker than closed-cell ones of a similar size. See the spray foam removal cost guide for published figures.
After the foam comes out
Once timbers are dry and any roof repairs are sorted, most homeowners choose to re-insulate the loft at ceiling-joist level with mineral wool, with the eaves kept clear so air can move under the roof. That keeps the roof cold and ventilated, which suits most older Merseyside homes.
When to call a professional
Call us if you can smell damp, see staining, or have been asked about the foam by a valuer. Soft foam can look easy to pull out, but loft ceilings are fragile, felt tears easily and the work creates a lot of mess. A local spray foam specialist will remove it safely and give you the photos and report a surveyor will want.
Soft foam in your loft?
Tell us what you have noticed and whether a sale or remortgage is involved. Call 07777 659786 or fill in the form and we will call you back.
Frequently asked questions
What does open-cell spray foam look like?
It is usually pale white or cream, matt and quite thick, often filling the full depth between rafters. It feels soft and spongy, squashes under your thumb and springs back, and you can tear a small piece off fairly easily. If it is hard and rigid instead, it is more likely to be closed cell.
Is open-cell foam easier to remove than closed-cell?
Generally, yes. It is softer and does not usually bond as hard to felt and tiles, so removal tends to be quicker. It still needs care, because the bulk is large, it is messy, and the felt or membrane behind it can be fragile. Every roof is different, so we confirm timings after seeing the loft.
Can open-cell foam cause condensation?
It can contribute. Open-cell foam lets water vapour pass through, so warm, moist air from the house can reach the cold roof underside behind it and condense. If ventilation is poor, that moisture can sit against felt and timber. Not every loft is affected, which is why we moisture-check timbers once the foam is off.
Do lenders accept open-cell foam?
Some lenders are more relaxed about open-cell foam than closed-cell, while others are cautious about any spray foam. Policies vary and change, so check with your own lender or broker. Our page on spray foam and mortgages explains the usual scenarios.
My open-cell foam smells. Should I be worried?
A musty smell often points to damp, either in the foam or in the timber behind it. Some people also notice a chemical smell from a poorly mixed install. Either way, it is worth having the loft looked at. We can inspect it and tell you what we find before you decide on removal.