Phenolic foam insulation is made by combining phenol-formaldehyde resin (note the presence of formaldehyde, a hazardous chemical and known carcinogen), a foaming agent and a hardener. When all three are mixed an exothermic reaction causes foaming followed by rapid setting.
Usually now available as rigid boards or panels sometimes as a backing to plaster or chip board.
- Relatively low embodied energy – in comparison to similar products.
- Good fire performance. Very low flame spread, negligible smoke emission and very low levels of toxic gas emission.
- Can be cut and shaped accurately. Often used to closely insulate pipes and can be reused.
- Lightweight, strong and durable in higher density applications.
- Can shrink. If applied as a foam then it can shrink when cured.
- Moisture resistant.
From 0.018 W/m.K, but typically in the range 0.020 – 0.023 W/m.K (Watts per meter Kelvin ~ lower value is a better result)
Kingspan Kooltherm is available for around £8 square metre.