What other issues can substituting insulation cause?
In addition to raising energy bills, substituting one insulation product with another could also lead to other potentially serious issues.
For example, in some cases we have seen contractors combine two or more insulation boards in a single layer. This may happen because the merchant has run out of the original material or simply because they have spare boards or offcuts from another area of your project or another project altogether.
Installers may assume that because certain products look very similar, they are interchangeable. However, these products may have very different performance characteristics which can lead to problems. For example, if certain areas of a wall are insulated with a lower performing insulation than others, they can allow heat to escape more quickly leading to cold spots forming. This can cause condensation to form and potentially lead to damp and mould issues.
Aside from their thermal performance, there are several other aspects of the performance and design of insulation products that can lead to issues when a product is substituted without proper consideration. These include:
Fire performance – all insulation products are given clear ratings for reaction to fire performance. In some applications, the insulation may need to achieve a specific rating to comply with the Building Regulations.
Compressive strength – floor insulation boards may be designed to withstand additional compressive forces than boards used for walls or roofs. If the insulation is not designed to withstand everyday foot traffic, it can compress overtime, reducing its performance. In most cases, Kooltherm K103 Floorboard would be suitable for residential installs as it has a compressive strength of 120 kPa.
Specialist facings – some insulation boards are manufactured with facings which allow them to be used in specific ways.For example, our Kooltherm K106 Cavity Board features a vapour-open polypropylene fleece outer facing which resists moisture penetration. This can allow it to be fitted with a 10 mm residual cavity, rather than the 50 mm which is needed for many other boards.If it is replaced with another insulation materials without changing the cavity width it could potentially lead to damp issues.
These are just a handful of examples of the problems that can occur where insulation is substituted without proper planning. To avoid these problems, it is crucial to ensure what is being installed matches the plans.
