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What are the differences between closed cell and open cell foam?


Closed cell foam isn’t the only kind of spray foam available for insulation. Open cell foam allows air in for a low density, whilst closed cell foam is much denser and stronger as a result; read on to find out the key differences between the two.

Thermal characteristics

Closed cell spray foam insulation offers better insulation than open cell spray foam insulation, thanks to the lower thermal conductivity. Closed cell foams can offer a K value as low as .0.25W/mK, compared to open cell foams, which offer 0.039, which is how materials are measured for transferring heat.

Closed cell spray foam can be up to three times denser than open cell foam.

Water and water vapour resistance

Because of its structure, closed cell foams only allow for extremely low levels of water vapour to pass through its surface; it is completely water resistant too. Closed cell foam can significantly reduce condensation when applied to any kind of roof or wall.

Open cell foam expands much further than closed cell foam, and thus is not as water-tight. It’s a more flexible material and is softer as a result.

Compressive strength

Because the core density of closed cell spray foam is much higher than the core density of open cell spray foam, closed cell spray foam has compressive strength that open cell doesn’t.

Closed cell foam can be used to even enhance the structural stability of a building’s framework. It’s a rigid material, and doesn’t feel as spongey as open cell foam.

Are you looking for spray foam insulation? Get in touch with us today to find out about how we can tailor a service to your property or call 0800 690 6338.