Open Cell vs. Closed Cell Foam

Let it first be said that ANY foam, when applied correctly, is going to eliminate drafts, heat loss and moisture from entering your space, providing exceptional energy efficiency. At this point it becomes a matter of determining a “best value solution” for your project – which happens to be Spray-Tec’s specialty!


  • Lightweight, pliable
  • Looks “rougher” (less smooth) because of quick expansion rate
  • R-3.5 per inch
  • Moisture CAN permeate open-cell foam; closed cell foam allows for a very controlled diffusion of water vapor
  • Reduces sound transfer; almost twice the sound resistance than closed cell
  • BEST used for: attics, crawlspaces, filling all “nooks and crannies”

Some examples of open cell foam:



  • Rigid, dense
  • Higher R-value per inch; R-6 per inch
  • Provides strength to structure
  • More expensive to produce and must be applied in thinner, more accurate “passes” (which increases the cost of installation)
  • Acts as air AND moisture barrier
  • BEST used for: pole barns, commercial wall/ceiling insulation (can be blacked out and left as an exposed ceiling!), exterior applications (ask us about our TANK insulation!)

Some examples of closed cell foam:

Best insulation in Kentucky
Shelbyville insulation
Black out ceilings
Pole Barn with Open Cell Foam

An example of BOTH closed cell and open cell! Note the open cell on the ceiling and closed cell on the walls. 

Note the open cell on the ceiling and closed cell on the walls. 


Spray foam that is located in a living/working area MUST be covered by a fire-resistant material. Attics and crawlspaces are typically not subject to this rule.

Examples of thermal barriers include:

  • Drywall and plywood
  • Gypsum board (a drywall material with a fire retardant built in)
  • DC-315 paint that is sprayed directly onto the foam insulation

This is a great video if you’d like a little more information on the matter.

OR you can give us a call–we’d love to find the best solution for your project! 502.633.5499

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