Spray Applied Insulation – Domestic roofs

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When insulating the roof of a domestic building, spray foam must be installed in line with the manufacturers’ instructions and must be carried out by a registered and professional spray foam installer.  IMA has developed a code of practice for installers which sets out the requirements for the procedures involved when specifying and installing spray foam
products to the inside of roofs of domestic properties.

Whilst IMA does not represent installers or contractors of spray foam, it does represent some manufacturers and distributors of spray foam.  These manufacturers only ever supply to their approved contractors and we have worked with these suppliers to promote best practice and highlight the correct procedures for a spray foam installation.  These procedures include pre-installation surveys and including a roof condition analysis, condensation risk analysis, product identification and supply information, as well as a post-installation homeowner pack.  This information should be made available to lenders and surveyors who should always use it to support their decisions about mortgage finance.

All our spray foam members’ products are independently tested to achieve BBA or KIWA-BDA certification and installation must be carried out in-line with this certification in order to validate performance.

For those considering having spray foam installed, or who may have been cold called about installation we urge you to consider the following list of what to do or not do.  Similarly, if you are approached by a company to have a spray foam installation removed, seek professional advice as to whether this is necessary.  IMA was involved in the development of a protocol to provide a framework to assist property professionals and residential surveyors undertaking non-invasive visual inspections of spray foam applications to the inside of pitched roofs (see below).


– Ensure that the installer carries out a survey before installation and that you see a copy of this. Get advice from a construction professional if you do not understand it.

– Get a second quote from another reputable company.

– Ask the installer which brand of spray foam is being installed

– Check with the spray foam manufacturer that the company proposing to install the product is a registered, trained contractor to install that product.

– Ensure installers are licensed to install only the brand of insulation they have been trained to use.

– Ensure that you have all relevant permissions before work is agreed or started.

– Ask about product guarantees and installation warranties


– Respond immediately to cold calls trying to sell insulation, but do some research

– Be afraid to ask questions and to verify answers before agreeing to anything

– Let a sales person tell you that spray foam can be used to repair a roof*

  1. – Let the thought of rising fuel bills press you into making hasty decisions
  2. – Use spray foam to repair a damaged roof *

* It is possible to spray directly onto the underside of roof tiles in very specific circumstances and under very strict conditions, not least the roof must be in very good condition, be made of certain materials as well as other criteria specified in its certification to achieve compliance.

Surveys and mortgage lending

IMA is aware of the problem that some homeowners appear to be experiencing where the lender makes a snap judgement causing real consternation for the homeowner, only to reverse that decision when challenged by another experienced party.  If an installation has been done correctly with all accompanying pre-installation checks and post installation documents, there should be no reason for the lender not to provide the necessary finance.

Mortgage lenders should assess each project on its merits and if the installation has been carried out by a registered contractor, all information will be available for the mortgage company to confirm that the work meets all necessary standards.

In 2022/23 IMA spent time working as part of a group to develop a protocol to assist surveyors when inspecting homes with spray foam in roofs so that the default position is not simply to give a zero valuation where spray foam is present.  The group was established by the Residential Property Surveyors Association and Property Care Association and drew in contributions from a wide range of organisations and individuals including lenders, surveying groups, surveyors, spray foam suppliers, trade bodies and heritage organisations.  You can find the protocol here.

It is expected that this protocol will provide sufficient knowledge for surveyors to recognise competent and professional installations and to provide a route to lending approval.

IMA has also produced a Code of practice for the application of spray foam into domestic roofs, so this along with the stringent training regime provided to contractors by IMA’s supplier members should give confidence to both homeowners and lenders.