Spray Foam Insulation in Roof Spaces – What You Need to Know
- Nick Baldin
- Aug 22
- 2 min read
Updated: Sep 24
Spray foam insulation has been installed in many UK roof spaces over recent years. It is often promoted as a modern way to reduce heat loss and improve energy efficiency. However, it has become a serious concern for building surveyors, mortgage lenders, and insurance companies.

The main issue is that spray foam is applied directly to the underside of the roof coverings and timbers. This hides the roof structure, making it very difficult to inspect rafters and fixings properly. Problems such as damp, rot, or woodworm can remain unseen until they become severe. Spray foam can also reduce ventilation, trapping moisture inside the roof and accelerating damage to the timbers.
Because of these risks, many mortgage lenders refuse to lend on properties with spray foam insulation unless it is removed. Insurance providers may also refuse cover or increase premiums, as they cannot be sure of the roof’s condition. This can make it difficult to sell, remortgage, or insure a home with spray foam in the loft.
Building surveyors always highlight spray foam insulation in their reports. We explain to clients that it masks the roof structure and can hide defects. The usual recommendation is that the roof structure should be re-assessed once the insulation installed between the rafters has been removed. Buyers are warned of the possible costs and the impact on mortgage approval.
Unfortunately, removal of spray foam insulation is often costly and may cause damage to the rafters and/or roof coverings. There are, however, safer and more practical alternatives. Traditional loft insulation materials, such as mineral wool or insulation boards, provide good thermal performance, allow the roof structure to remain visible, and are easy to replace if required.
Buying a property is a major investment, and having the right advice at the right time is essential. Our experienced surveyors provide independent Home Buyer Surveys Level 2 and Level 3 across Dorset, Hampshire, Wiltshire, Berkshire, Surrey and west London. You can receive an instant online quote, and once confirmed, your survey can be booked quickly and conveniently. Get started today and make your property purchase with confidence.


