Problems arising from the installation of Spray Foam insulation are becoming ever more frequently publicised, raising questions as to why this insulation method, that has been used for over thirty years prior, is such a topic of concern?
In recent years mortgage and property professionals have highlighted issues regarding the mortgaging of properties where spray foam insulation has been installed. To the extent that certain lenders will not offer mortgage deals on properties with the insulation.
What is spray foam insulation?
Spray foam is a liquid foam that expands and hardens in situ to form a layer of insulation, typically used in roofs and attics. The application is often ideal for difficult to reach areas or tight spaces as a quick alternative method of insulation.
There are many different types of spray foam, each with slightly different performance properties, however, the most common type is spray polyurethane foam (SPF).
Although it may be considered a simple and easy way to improve a home’s insulation, SPF should be viewed as a serious modification to the home that shouldn’t be undertaken without serious consideration.
The benefit of using SPF is its better insulation properties. When compared to a traditional insulation material such as mineral wool, 100mm of spray foam insulation is equivalent to around 170mm of traditional loft insulation making it a quick, space saving, alternative.
As the cost-of-living crisis is creating an only increasing inflation to household utility bills, many homeowners are being persuaded to install spray foam insulation to combat the costs and make their homes more energy efficient with, at the time of writing, the government even including it on its approved list of measures for energy efficient home improvement initiatives.
So, why is it an issue?
SPF comes in two varieties: open cell and closed cell. While open cell SPF is spongey and lets water vapour pass through, it is not as good an insulator. Closed cell spray foam comparatively is a great insulator but doesn’t let water vapour pass through it. This can lead to severe condensation issues.
Whereas newer build homes are often designed to incorporate this type of insulation, older homes are not and do not have the correct ventilation for this type of material. As hot air rises through the property, this lack of ventilation creates a build-up of moisture where the air cannot escape, causing condensation to become trapped. Overtime this can lead to rot and structural damage to the timber and roof materials.
If spray foam insulation is installed to the structure of the roof, it can make it difficult to fix or identify issues where the spray foam conceals the roof to visual inspection.
This means that if there is damage to the roof or any leaks, they can go unnoticed, allowing for water and moisture to enter the roof space and rot the timber structure.
As the governments drive towards more energy efficient homes, more contractors have been pushing the sale and installation of SPF. However, with the high risk presented from incorrectly installed insulation, a lot of lenders will not lend on a home where spray foam has been installed.
Given the high risk to the mortgageability of a property with the insulation, and the unregulated nature of the spray foam industry, there have been calls for the government to step in and, at very least, issue a warning to homeowners to prevent them falling victim to shoddy spray foam installation.
However, as energy costs continue to rise and contractors continue to push the benefits of spray foam, it is essential that homeowners take the initiative to research the implications of installing the material into their homes before making any serious alterations.
For more information on the installation of spray foam insulation in residential properties, read the latest RICS consumer guide (March 2023) which offers a detailed and impartial breakdown on the subject tailored specifically for consumers:
https://www.rics.org/news-insights/rics-release-new-spray-foam-consumer-guide