Spray Polyurethane Foam, also known as spray foam insulation, has come under the spotlight recently but continues to be used even today and is regularly offered to homeowners in an attempt to improve the thermal insulation within roof spaces of properties. There are typically two different types of spray form insulation, open cell and closed cell.

Spray foam insulation is really as it sounds and involves spraying insulating foam within a roof space and is often marketed as a space saving and quick way to improve properties thermal insulation within the roof space. It was also in previous decades used in cases where the roof coverings were failing and, in this instance, was commonly used to provide stability and act as a glue to hold the roof coverings in place as a temporary measure.

So, what are the potential issues and risks with this method of insulating a roof space?

Homeowners should be aware that having spray foam insulation applied to their roof space may affect the mortgageability of the property. In today’s market, many lenders will not lend against properties that contain spray foam insulation, whilst limited lenders will only lend against properties containing a small amount of spray foam. Lenders have different lending criteria that they consider which is also frequently subject to change however, it is important for homeowners to be aware that this type of insulation could affect the mortgageability and therefore, the saleability of their property.

As spray foam insulation typically encapsulates roof timbers and can even block off vents there are concerns that moisture and condensation could be consequently caused, risking deterioration to roof timbers and high levels of moisture being trapped within the roof space. As any areas concealed by spray foam such as timbers are then concealed from view, defects can remain hidden for long periods of time, often not being discovered until significant in nature. There are also concerns about the fire safety of this method and material, as spray foam is typically highly combustible. It is also worth noting that more roofs are typically designed to act as either cold or warm roof systems and the application of spray foam insulation if applied incorrectly, could prevent the roof system from acting as designed.