What is the difference between open and closed cell spray foam?

Asked By: Yaniris Sequera | Last Updated: 2nd March, 2020
Category: home and garden indoor environmental quality
4.9/5 (19 Views . 9 Votes)
Closed cell foam has cells which are sealed off so air doesn't get inside the structure at all. The major difference between the two foam options is that closed cell foam tends to be harder or firmer while open cell foam is softer or less firm.

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Besides, which is better closed or open cell foam insulation?

Closed cell foam has a higher R-value than open cell foam, usually about 6.0 per inch. This higher rating makes closed cell foam better at keeping heat in or out of a structure. Open cell foams have an R-value of around 3.5 per inch.

Additionally, what type of spray foam insulation should I use? The types of spray foam insulation Primarily in residential and commercial construction, open-cell and closed-cell spray foam is used while high-density spray insulation is used as roofing foam in commercial or industrial construction.

Similarly, it is asked, what is closed cell foam insulation?

Closed cell foams are the most popular type of insulation used in remodeling and new construction applications. They can provide support to the structure due to the composition of their cells. They protect against water damage, and generally provide a higher r-value per inch than open cell foams.

Is closed cell foam waterproof?

Open cell foam is not waterproof or water-resistant. In contrast, closed cell foam is water-resistant. However, only high-density closed cell foams are waterproof.

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How long does closed cell foam last?

With proper application, Spray Foam will last the lifetime of your home. Even roofing applications will last upwards of 30 years, with proper long-term maintenance. Spray Foam insulation adheres extremely well to virtually all substrates, and maintains its rigidity once dry.

Does closed cell foam need a vapor barrier?

Closed cell foam is higher density foam, and a moisture barrier. Most closed cell foam used for insulation range from 1.7 lb to 2 lb. Open cell foam is not a moisture vapor barrier, and will allow moisture to pass. Closed cell has a higher R-value than open cell.

Does Spray Foam cause mold?

Sealing the attic is probably the most critical, in terms of counteracting moisture. As a product, spray foam insulation does not attract mold. And unlike wood or metal, spray foam does not rot, rust or deteriorate. It will control indoor humidity and condensation, and therefore prevent mold from growing and spreading.

Is expanding foam water resistant?

Product Q&A
Moisture-curing, self-expanding foam adheres to all common building materials. Resistant to water, heat and ageing. Ideal for filling large holes, voids, gaps around window and door frames and around exterior pipes.

Does spray foam insulation cause moisture problems?


Spray Foam Myth: Insulating with spray foam insulation at the roof line will cause moisture problems with the roof sheathing. In an unvented attic scenario, to limit air leakage as well as any associated condensation at the roof line, a continuous air barrier is required.

Does spray foam stop water?

Using expanding polyurethane foam is one of the best ways to stop water leaks because the foam will expand into the cracks and help prevent future leaks. Expanding foam bonds to any type of surface and will quickly and effectively solve your water leak problems.

Does spray foam insulation kill mold?

Closed cell foam will kill mold. It cooks it. Molds cannot survive the exothermic heat and the ensuing encapsulation.

Does open cell foam absorb water?

Open-cell foam can absorb more water than a closed- cell product when submerged (although some open-cell foams absorb much less water than others).

What is the R value of 2 inches of spray foam?


Open-cell spray foam absorbs and holds water. It has a lower R-value per inch than closed-cell foam and is vapor-permeable. The R-value is R-3.5 to R-3.6 per inch, so filling a 2×4 cavity yields about an R-13.

What is the R value of closed cell foam?

Open-cell spray foam has an R-value of about R-3.7 per inch, while closed-cell spray foam has an R-value that may be as high as R-6.5 per inch.

Can you spray foam insulation yourself?

Quick & Easy Spray Foam Insulation:
An Air Barrier – Just 1 inch can seal the air leaks that cost you bundles. A Vapor Retarder – Our closed cell insulation does not absorb moisture, unlike open cell spray foam insulation, cellulose, or fiberglass. High-R Value Foam Insulation – R-7 in 1 inch of cured foam.

Is closed cell foam good for soundproofing?

Closed cell foams, such as our “Super Soundproofing Mat” absorbs readily but does not pass sound easily, making it a good barrier as well. Made of vinyl nitrile, it will not absorb odor and has excellent moisture, durability and fire resistance.

Can you spray closed cell foam over open cell foam?

No, you do not want to spray closed cell foam over open cell foam or fiberglass or cellulose. If you had a roof leak the water would not have anyway to get out.

Is spray foam insulation worth it?


The EPA's Energy Star Association has shown that monthly energy bills can be cut by up to 20% when air leaks are sealed and efficient insulation is installed. The initial cost of spray foam insulation is well worth the investment, when factoring in the overall savings that will be headed your way over the long term.

Is closed cell spray foam safe?

According to the EPA, “homeowners who are exposed to isocyanates and other spray foam chemicals in vapors, aerosols, and dust during or after the installation process "run the risk of developing asthma, sensitization, lung damage, other respiratory and breathing problems, and skin and eye irritation."

Can you spray foam the underside of your roof?

Open- or closed-cell spray foam is applied to the underside of the roof sheathing, and additional fiberglass or cellulose insulation is blown in as a cost-saving method for meeting high insulation requirements and filling in the cavity space between the rafters to the ceiling deck.