If you want to reduce your carbon emissions and keep your energy bills low, installing insulation and draught-proofing can reduce heat loss and, therefore, your energy needs and bills. Spray Polyurethane Foam (SPF), hereinafter referred to as ‘spray foam’, is a form of insulation material that can be applied to roof spaces, walls and floors.
Is it a good idea?
Spray foam insulation may seem like a simple way to reduce heat loss in your home, but it should be viewed as a serious modification. This consumer guide aims to inform the homeowner on the ways in which spray foam insulation could impact a property. Like all insulation, its material properties, design and installation need to be considered properly before application to ensure it is suitable for your property. Introducing new materials can have an impact, both positive and negative, on how your building performs. For example, sealing hot air inside can keep you warm but can also seal water inside and make roof repairs more difficult. Insulation of all kinds can also negatively impact how other parts of the building perform depending on its form, position and most importantly, the condition of the existing materials. Incorrectly installed insulation can negatively impact ventilation and result in moisture damage.
What else do I need to consider?
A property needs to be wind and watertight before any money is spent improving its energy performance. If a property is not maintained, it will be vulnerable to rainwater getting inside. Adding insulation to a poorly maintained roof will increase this vulnerability and accelerate the decay of any untreated timber roof structures.
A typical pitched roof loft void is designed to have ventilation to balance water vapour in the air, reducing the risk of condensation. Traditional insulation is typically laid above habitable rooms at ceiling level. This is called a ‘cold roof’ because the loft becomes cold. Installing spray foam to the underside of a roof structure is called a ‘warm roof’ because the roof space becomes warm.
Before installing spray foam insulation, consider the following:
• Do not accept ‘cold-call’ or unsolicited offers relating to spray foam installations.
• Do not install spray foam insulation in a listed building or other protected building or structure without obtaining listed building consent in advance.
• Do not carry out isolated alterations without careful due diligence and planning.
• Do get advice from an independent, impartial professional if you are considering alterations or modifications at your property (someone who does not have a commercial interest in selling you their product).
• Do look after and maintain your property in good repair, keeping it wind and watertight.
• Do consider the whole property before carrying out any alterations.
• Do consider how your property is designed to perform – specifically, understand where ventilation is needed in your property.
• Do consider where you live in the building and consider installing more insulation next to your living spaces, for example, at ceiling level in the loft to keep the heat near the rooms you live in.
• Do check with your mortgage provider whether their lender policy allows the installation of such products.
• Do check with your insurance provider whether their policy allows the installation of such products with potential increased fire risk.
The RICS (Royal Institution of Chartered Surveyors) have produced a consumer guide relating to ‘Spray Foam Loft Insulation – a clear and impartial guide’. RICS members can help property owners in a variety of ways, so whether you want expert advice and a professional assessment of your issue, an opinion on costs, representation, or a professional to manage a project for you. RICS website - Find a Surveyor - to find a RICS member in your area.
