What is open celled foam?

Category: home and garden indoor environmental quality
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Open cell foam is a rubber-like product made by incorporating an inflating agent, such as sodium bicarbonate, into the rubber compound; this agent gives off a gas, which expands the rubber during vulcanization. Foam is usually classified as “open cell” when more than half of its cells are open.



Similarly one may ask, 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).

Secondly, does open cell foam mold? According to Frank, moisture can be a concern if you construct a home and insulate it with open-cell spray foam. If closed cell is used, the moisture cannot make its way to the wood and present mold issues.

Besides, where is open cell spray foam used?

Open cell spray foam has a very high expansion rate, sometimes as much as 100 times over. This makes it an ideal option for homes because it gets in the nooks and crannies in attics, crawl spaces, and rim joists. Closed cell spray foam has very minimal expansion when applied.

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.

37 Related Question Answers Found

Is spray foam waterproof?

Answer: Some spray foam insulations are waterproof. This depends on the density of the foam. Lower density closed cell foams are water resistant, but not completely water proof. However, higher density closed cell foams can be water proof.

What is the R value of open 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.

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 foam insulation flammable?

Yes, spray foam insulation is considered flammable. No matter what a salesperson may try to tell or sell you, all foam plastic materials must be considered flammable in accordance to the international building code.

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.

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.

What happens if open cell spray foam gets wet?

Open cell spray foam insulation will still dry completely after getting wet. In addition, because spray foam is not a “food” for mold, there is little danger of mold becoming a problem even if it gets wet. Closed cell foams also do not absorb water, which is very beneficial in flooding zones.

Will polyurethane foam absorb water?

Moisture absorption in foams is dependent on the type of foam but also on the environmental conditions. Closed-cell spray polyurethane foams do not absorb water like wood does; in fact foam that is sitting in water may retain some of that water when it is removed from the water, but it dries out within a few days.

Is great stuff open or closed cell?

Closed-cell foam provides a vapor barrier, a harder finish and higher R-value. Canned foam like GREAT STUFF™ is a closed-cell foam that comes in "single-component" form. The closed-cell foam that contractors use on large-scale spray foam jobs is also known as "two-component" foam or polyurethane foam.

Is urethane foam waterproof?


Closed cell Spray Polyurethane Foam (SPF) lies at the heart of the Dura-Foam roof system. SPF is a waterproof material that also has a high insulation value of R 6.25 per inch. When exposded to water, this roofing material remains dry because its foam cells are closed and impenetrable by water.

Which is better closed cell 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.

Does Foam soak up water?

Home / Does the foam absorb water? No. However, water can work its way through the foam under pressure or by gravity force. When the foam is placed on water it will float and upon removal it will not contain any water and it does not lose any of its insulating properties.

Does closed cell foam absorb sound?

Closed cell foam is a specific type of foam that boasts a higher R-Value than its open cell counterpart. Because of this, closed cell foam results in a denser material that works better at absorbing low-frequency noise.

Is foam board porous?


The foam surface is less porous than paper, but you should be able to get things to stick pretty well with enough time and effort. The removable paper coating on foam board can also cause problems if you're trying to glue two pieces of foam board together.

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.

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.