Closed Cell Vs Open Cell Insulation

As is common knowledge, spray foam is a chemical mixture which has the capacity of swelling up to 10 times its liquid volume after it is allowed to harden. This expansion property has helped it become useful as a lucrative alternative to conventional insulation like fiberglass in buildings.

Now spray foam insulation can be classified into two broad divisions – closed cell and open cell.


Closed Cell foam

In closed cell foam insulation, the cells are completely closed,  densely packed together, and smaller in size. They are inflated with a gas which helps the foam expand and insulate effectively. Since the cells are closed they prevent air and water vapour from getting in, a nifty advantage that its open cell counterpart does not offer. It also works well as a roofing insulatory material aside from being used in other outdoor projects.  But it can be used anwhere. Aside from all this, closed cell foam has another key utility factor working in its favor – it can be obtained in varying shapes and densities.Closed Cell vs Open Cell Insulation


Open Cell foam

As has been mentioned above, open cell foam is composed of tiny cells which are not enclosed. This type of foam is less expensive for obvious reasons of having fewer chemicals as constituents. It succeeds in blocking out air but is not much of a barrier against the entry of water vapour. Since the cells aren’t closed, air fills up the open space inside the material sometimes causing the foam to become weaker and easier to penetrate in comparison to closed cell foam. It is not much useful for insulation purposes in the outdoors but when used in the interior walls it can help in sound reduction.

The following are the advantages of closed cell over open cell insulation.

Pros –

  • Closed cell foam has greater strength, higher thermal resistance, and prevents leakage of air and water vaour

Cons –

  • Closed cell foam is denser, requires more material
  • More expensive than its open cell counterpart
  • Even though it has a better R-value (higher the R-value the more effective is the insulation), the rate per R is higher than that of open cell foam

Irrespective of closed or open, spray foam insulation has been proven to reduce energy expenses. Buildings in the U.S. which come with spray foam insulation are at least 50% more effective at preventing energy loss through air infiltration. Spray foam insulation also helps guard against the growth of mold and mildew and the decay of wood. In addition to controlling temperature and keeping moisture out, it also helps in soundproofing.