Spray Foam Insulation near you

The report, Spray foam insulation applied to timber sloped roofs in dwellings, was initiated by the then Department for Levelling Up, Housing and Communities and completed and published by the Health and Safety Executive as the Building Safety Regulator in February 2024. It modelled moisture and timber decay risk for sprayed foam on typical domestic timber roofs, across open-cell and closed-cell foams, high- and low-resistance underlays, London and Newcastle climates, and roofs with and without an air and vapour control layer.

Its headline finding is not that spray foam fails. It is that risks are low when an open-cell, moisture-permeable insulant is applied in accordance with the prescriptive roof constructions in BS 5250:2021. Those constructions include an air and vapour control layer on the warm side of the insulation, and a space left between the insulation and the roof underlay, which needs to be specifically ventilated from the eaves where the underlay is a high-resistance type. The report notes such spaces can be created with card spacers inserted between the rafters or similar techniques.

The risk appears where those details are missing. Applied to a high-resistance underlay with no air and vapour control layer, open-cell foam modelled as high risk in both climates. Applied directly onto tiles or slates, the modelling returned high risk in every scenario tested, open cell or closed, with or without a vapour control layer, in both climates. The report also records a trade-off worth knowing: ventilating the loft void heavily would reduce mould and condensation risk but would almost entirely undermine the thermal benefit, so that the original purpose of insulating would be lost.

The Property Care Association's homeowner advice makes the inspection point plainly: sprayed foam creates a thick, continuous layer that completely obscures the underlying roof structure. A roof that cannot be seen cannot be assessed, which matters for a leak that has been running quietly for two winters, for beetle or rot in the rafters, and for a valuer trying to form a view without opening anything up. That is an evidence problem rather than a physics problem, and it persists even where the installation was competent.

The physics problems are the ones the modelling isolates. Additional scenarios in the 2024 report found that a colder loft void, which is what you get if the original loft floor insulation is left in place below a sprayed roof slope, increases mould growth risk; that more air leakage through the ceiling, from cracks or an unvented bathroom, increases the risk of condensation in the void; and that imperfect roof coverings letting water through, or small gaps between the sprayed foam and the rafters, both increase the risk of condensation gathering on the cold side of the insulation, with those risks likely to be highest where closed-cell foam was used.

The PCA's summary of the consequences is the familiar list: timber rot and decay, mould growth, corrosion of metal components, and difficulty and expense if the roof later needs repair. None of that is automatic. All of it is more likely where the roof was already tired, the underlay was a high-resistance membrane, or nobody left a ventilated space.

There is a real lending problem, and it is narrower than the headlines. RICS's consumer guide says the presence of spray foam could affect a surveyor's professional opinion of value, that surveyors may request specialist reports where they find it, and that homeowners should check with their mortgage provider whether the lender's policy allows such products. Concern started in particular parts of the market, notably equity release, and spread. RICS and the PCA both record that the difficulty valuers have in assessing a roof space they cannot see has led certain mortgage companies to refuse to lend on a property with sprayed foam applied to the roof.

What that does not mean is that lenders as a class refuse. Policy varies between lenders and between products, a surveyor works to the instructions and policy of the lender who instructed them, and a documented, competently installed and properly ventilated system is a different proposition from an undocumented one. Cornwall Council's trading standards advice puts the other half of it bluntly: removal is not always necessary and does not guarantee mortgage approval.

The route back to evidence is an inspection protocol. The Property Care Association, working with the Residential Property Surveyors Association and with input from lenders, policymakers and other specialists, developed a protocol for non-invasive visual inspection of sprayed polyurethane foam in domestic pitched roofs, published in March 2023, so that surveyors and lenders could make decisions about individual properties from observation and evidence rather than from the presence of foam alone. It is explicitly not an installation standard.

Removal has become its own industry, and a good part of it is a scam. Trading standards services have warned about unsolicited phone calls and doorstep visits, claims that insulation must be removed urgently, and businesses claiming to work with the government or the council, with consumers pressured into paying thousands of pounds for work that was not needed. The standard advice is not to agree to work offered through a cold call, not to be rushed into a decision, to get an independent assessment from a qualified surveyor first, and to obtain more than one quotation before anything is committed.

Whether removal is the right answer depends on findings, not on the presence of foam. The PCA reported to its members in 2025 on more than 500 sprayed foam assessment surveys carried out by its registered surveyors over fifteen months: 79 per cent of properties showed one or more divergence from the inspection protocol, 35 per cent had defects caused by the installation, 27 per cent needed re-quilting or re-roofing, 16 per cent needed no action at all, and 6 per cent needed nothing more than additional paperwork from the installer. Roughly one in five needed no physical work, and a further slice needed documents rather than demolition.

Where removal is genuinely required it is difficult and expensive, because the foam is bonded to the structure it was sprayed onto. RICS notes that it is not easily reversible and that it should not be installed in listed buildings, since removal could damage the existing structure. That is a strong argument for an assessment first and a decision second.

Quotations vary by more than the area sprayed. The variables that matter are the roof's construction and covering, whether the underlay is high or low resistance, whether a ventilated space and a vapour control layer are being designed in rather than skipped, the condition of the existing timbers, whether an independent survey and condensation risk analysis are included or charged separately, access and the state of the loft, and whether the work includes making the ceiling below airtight. Removal or remediation of an earlier installation is priced differently again, and depends entirely on what an inspection finds.

LokalMatch introduces you to firms; it does not do the work or judge it. Describe the roof and what you are trying to achieve once, add your postcode, and contractors covering your area come back to you. Using LokalMatch costs homeowners nothing, and the businesses pay for the leads they receive. LokalMatch does not install anything, does not set prices, and does not vet, rank or recommend the companies that respond, so the independent survey, the certification and the guarantee remain things you should insist on yourself.