One of the most common questions we get from people trying to figure out what spray foam insulation product is right for their application is what is the difference between closed and open cell.

There is a great difference between the 2 and each has it’s uses.

Closed cell spray foam is extremely dense, approximately 2 lbs. per square foot., and that density is what makes it such an effective insulation. It blocks moisture, air, and provides a rigidity that makes your building stronger.

Most building applications call for closed cell foam.

Open cell spray foam has a much lower density, anywhere from .4 – 1.2 lbs. per square foot. Due to the lower density it’s r-value is only 3.5 per inch.

Although it is less expensive than closed cell spray foam, more is required to achieve the same insulating value.

Open cell is permeable to moisture vapor, so it might be necessary to employ an additional moisture barrier when using it.

It does however make for an excellent sound barrier, about twice as effective as closed cell spray foam.

Closed Cell Spray Foam Insulation Facts

  • Density is approximately 2 lbs. per square foot
  • R-value is approximately 6 per inch
  • Highly effective air barrier
  • Extremely low moisture vapor permeability (perm rating is < 1.0)
  • Excellent resistance to water
  • Provides optimum insulating and strength characteristics for most building applications
  • It is the most efficient insulation available

Open Cell Spray Foam insulation Facts

  • Density is .4 – 1.2 lbs. per square foot
  • R-value is approximately 3.5 per inch
  • More permeable to moisture vapor (perm rating is 16 per 3″ thick)
  • Very effective sound barrier – twice as effective as closed cell
  • Not for exterior use
  • Should not have any direct contact with water

Foam Kit Solutions Products

We offer 2 kinds of all purpose closed cell kits: Our standard closed cell and our E-84 class 1 compliant kit. Our E-84 product has been tested and been certified as a Class 1 Fire Retardant Building Material.

Closed Cell E-84 Class 1 Fire Retardant Kits

605 Board Feet Closed Cell Spray Foam KitIf the area to be insulated is going to have exposed insulation it is recommended that you use the E-84 Class 1 Fire Retardant product. With an R-value of 6.8 per 1 inch depth, you are sure to create an extremely well insulated area that is air and moisture impermeable, safe, and will pay for itself in energy savings.

Quick Cure Closed Cell Kits

605 Bd. Ft Quick Cure Spray Foam KitIf your insulation application is going to be covered by drywall you can save a little money and use one of our standard closed cell kits. Although not E-84 Class 1 rated, all of our products contain flame retardants. This product is best used where it will be covered by drywall.

Open Cell Sound Barrier Kits

For a superior sound barrier, use our Open Cell Sound Barrier Foam. It features a Sound Barrier Class Rating of 35 at 3 inches thick, and an r-value of 3.5 per inch.

Other Applications

We offer products for every application including roof patch, and commercial vehicle insulation.

You can see them all in our shop.

If you have any questions we are always ready to answer them. Just give us a call. We have helped thousands of people just like you to make their project a success.

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Todd Hensel

With 17 years experience applying spray foam and 10 years operating Foam Kit Solutions, Todd knows how to do the job right. Todd is always happy to answer questions or offer advice.