What paperwork should I get for spray foam insulation?

The reason the paperwork matters more for spray foam than for most insulation is that the material is hard to undo. Spray foam can be used in floors, but it is difficult to remove from the floor joists, wires and pipework, so it can present a problem when maintenance work is needed in that area in the future². It has been in use for more than 30 years and can be used in a number of ECO-eligible insulation applications to fill voids and gaps³. Once it is in, the certificate and the guarantees are the only record of what was done.

There is also a market problem behind the paperwork. Many cases of consumer harm involve cold calling, mis-selling, and rogue traders⁴, and rogue traders are known to use aggressive sales tactics to pressurise homeowners into installing spray foam insulation⁵. In Parliament it was noted in June 2026 that many households who had spray foam installed have found they have encountered problems when selling their home⁶. Documents obtained before work starts, and kept afterwards, are the household's defence.

Paperwork on a spray foam job: survey report, product certificate and guarantees

The four documents form a chain. The survey report establishes that the property was assessed before anything was sprayed. The product certificate identifies the material. The trader guarantee covers the workmanship. The manufacturer guarantee covers the product. Independent guidance lists exactly this set: a report from a survey that was done before any work started, a product certificate showing what type of spray foam was used, a guarantee from the trader who carried out the work, and a guarantee from the manufacturer of the insulation¹.

Each document answers a different question later on. The survey report answers whether the roof or floor was suitable. The product certificate answers whether the foam is open cell or closed cell, which matters because the two behave differently in a roof. The guarantees answer who pays if something fails. Where a scheme is involved, the same principle applies: grant recipients are told that if they offer guarantees or warranties, they should make sure they get these documents after the installation⁹.

The material itself is usually made from polyurethane and filled with bubbles of gas or air, in open-cell and closed-cell types³. It can be sprayed on the inside of roofs, in walls and floors¹. Retrofitted spray applied closed and open-cell polymeric insulation to the underside of roofs of dwelling properties has been tested for fire performance, and such sprayed configurations can satisfy the highest demands for roof covering classification as currently included in Approved Document B guidance¹⁰. That testing evidence sits with the manufacturer, not the household, which is another reason the product certificate is worth keeping.

Pre-work survey report: what it should show and why it matters first

The survey is the document that decides whether spray foam should go in at all, and it is the one most often skipped when a household is under sales pressure. Independent guidance states that a survey should include a U-value calculation, which shows how well-insulated your home is, and an assessment of the risk of condensation occurring, along with identifying any problems and the measures needed to prevent them³. Without that assessment, a household has no record that moisture risk was considered.

The wider installer standards point the same way. Under the Kiwa Cavity Wall Insulation Installer Scheme, the property must be surveyed thoroughly before any material is installed¹¹. The Installation Assurance Authority requires evidence of pre and post works background ventilation test results, photos and floor plan drawings to prove the presence of existing wet room ventilation and to ensure due consideration of factors such as mould and condensation risk¹². Those are installer obligations, but they generate documents a household can ask to see.

Where a floor is being treated, a survey may carry a direct cost. For robotic underfloor installation, a household may also be required to pay for a survey in advance, to establish whether the floor is suitable¹³. That is a charge before any work, and it should produce a written report.

The moisture question is not theoretical. Official guidance on the moisture risk of spray foam insulation applied to timber sloped roofs applies to England¹⁴, and the government has published fire testing recommendations for spray foam roof insulation¹⁰. A survey report that records the roof construction, the ventilation provision and the condensation risk is the household's evidence that these issues were addressed before the foam went in.

Product certificate: identifying the type of spray foam used

The product certificate is the document that names the material. Spray foam insulation can come in two forms⁷, and both open-cell and closed-cell spray foam insulation are usually made from polyurethane and filled with bubbles of gas or air³. The certificate should state which one was applied, because the two have different insulation values, different vapour behaviour and different implications for a roof.

The certificate also ties the installation to a manufacturer. That matters because the manufacturer guarantee is issued by that company, and a claim under it will be assessed against the product that was actually supplied. A certificate that names a product but not a batch, or names a generic "spray foam" without a maker, leaves the household without a route to the manufacturer.

Independent guidance on the documents to hold puts the product certificate second in the list, after the survey report and before the two guarantees¹. The order reflects how a later inspection works: the survey says the property was suitable, the certificate says what went in, and the guarantees say who stands behind it.

Where the work was funded through a scheme, the certificate also supports the lodgement record. Under the ECO4 delivery guidance, measures should be installed by or under the responsibility of a TrustMark registered installer and have a relevant certificate of lodgement¹⁵. The product certificate and the lodgement certificate are different documents, and a household should expect to hold both where a scheme was involved.

Guarantees from the trader and insurance-backed guarantees: the two documents to check

Two guarantees are expected, and they cover different things. The trader guarantee covers the installation workmanship. The manufacturer guarantee covers the product. Independent guidance lists both, alongside the survey report and product certificate¹. A household that holds only one of the two has cover for half the risk.

The trader guarantee is only as good as the trader. Where a business stops trading, a workmanship guarantee issued by that business is difficult to enforce, which is why insurance-backed cover is treated separately. Independent guidance on professional insulation installation describes the expected package as TrustMark registered installers, membership of a trade assurance body such as the Installation Assurance Authority, Cavity Insulation Guarantee Agency or Solid Wall Insulation Guarantee Agency, public liability insurance, employer's liability and an insurance-backed guarantee¹⁶. The insurance-backed guarantee is the element that survives the installer.

The Installation Assurance Authority operates a complaints procedure and requires proof of ownership before it will act: a copy of a Land Registry extract or Mortgage Statement and a copy of a utility or council tax bill, or a tenancy agreement if the property is tenanted¹⁷. That is a practical point for anyone assembling a claim file, because those ownership documents sit alongside the installation paperwork.

TrustMark registration and ECO-funded work: when the installer must be registered

For work funded through the Energy Company Obligation, registration is not optional. Installers under ECO must be TrustMark accredited and will have a registration number, except in the case of installers of district heating connections¹⁸. The same requirement runs through the ECO4 delivery guidance, which states that measures should be installed by or under the responsibility of a TrustMark registered installer and have a relevant certificate of lodgement¹⁵.

The requirement extends beyond ECO. Under the Warm Home Discount (England and Wales) Regulations 2026, the boiler or central heating system is installed by, or under the responsibility of, a person who is registered with TrustMark, with a certificate of lodgement issued by the operator of TrustMark¹⁹. In Scotland, Home Energy Scotland Grant and Loan funding requires a TrustMark registered contractor for external wall, internal wall, flat roof, room-in-roof or floor insulation²⁰, and the Private Rented Sector Landlord Loan requires a TrustMark registered installer for solid wall, underfloor, flat roof or room-in-roof insulation²¹. Where Home Energy Scotland funding is used for solid wall, underfloor, flat roof or room-in-roof insulation, the installer is required to be registered with TrustMark for those measures²².

TrustMark is described in council guidance as a government endorsed quality scheme²³ and as a competent person register for finding an installer that will assess your circumstances and property to identify suitable measures²⁴. It is also the body that reported quality problems in scheme-funded work: TrustMark notified DESNZ of suspected fraud involving retrofit businesses overclaiming for work undertaken in April 2024, and of high levels of external wall insulation installations that did not comply with the relevant quality standard in October 2024²⁵. A parliamentary committee noted that neither TrustMark nor DESNZ have been able to provide minutes of meetings which took place between 2022 and 2024²⁶. Registration is a starting point for checking an installer, not a guarantee of the work.

Listed buildings: consent needed before any spray foam is installed

In a listed property the paperwork question starts before the survey. Listed building consent must be obtained before installing spray foam insulation anywhere in a listed property, and this is unlikely to be granted⁵. Council guidance confirms that introducing new materials to the property, such as insulation, is a case where consent is required²⁷, and that more disruptive work like internal or external insulation will usually need Listed Building Consent²⁸. Listed buildings will require listed building consent for any significant work²⁹, and new roofing materials require listed building consent as an external alteration³⁰.

The practical consequence is that a household in a listed building should hold a consent decision, or a written refusal, before any installer arrives. An installation carried out without consent creates an enforcement problem that no product certificate or guarantee can resolve, and it sits alongside the mortgage and sale difficulties already reported for spray foam generally⁶.

For listed buildings, the relevant pages are listed buildings insulation and glazing and planning permission for insulation, cladding and windows. The consent regime is administered by the local planning authority, so the documents come from the council, not the installer.

When paperwork is missing: the TrustMark 'Find and Fix' service and free home checks

Missing paperwork is common enough that a recovery route exists. TrustMark offers a free home check in which a qualified professional will look at the insulation to see if it was installed correctly, for wall insulation installed inside and outside your home³¹. The free audit involves a thorough inspection of the work completed at your property⁸. The audit line is 0333 555 1234, option 1⁸, and the same number appears in Welsh consumer guidance as the TrustMark telephone contact³².

The first step is to approach the installer and the manufacturer, because the product certificate and the manufacturer guarantee originate with them. If the installer has ceased trading, the lodgement record becomes the main lead. TrustMark holds lodgements for measures installed under its framework, and the scheme rules require a certificate of lodgement for ECO4 measures¹⁵.

Where a home check is arranged, the household should expect contact to be verifiable. The letter or visitor will quote your 'unique measure reference' number so you know it's genuine³¹, and a household should ask for their ID and 'unique measure reference' number to check they're genuine³¹. The same verification applies to TrustMark contact³². A caller who cannot produce both should not be admitted.

Removal is sometimes the outcome. Independent guidance lists the reasons for removing spray foam as damp and condensation, damage to the property, or needing to make a repair such as a roof repair¹. Where removal is proposed, the paperwork held from the original installation is what establishes what was installed and when, which is why the document set is worth reconstructing even years later.

For related subjects, see spray foam insulation, spray foam roof rot, how do I know if I have spray foam in my roof, insulation scams and cold calling and finding an insulation installer.