Can you mix open and closed cell foam?

Open cell foams have a surfactant that is designed to “overblow” the foam cell and crack or open it. Closed cell foams have less surfactant and it is designed to keep the cell wall closed. If you mix the open and closed cell foams together, you get extemely poor cell structure that is very course.

Is EPS foam open or closed cell?





closed cell insulation

Expanded Polystyrene Insulation, more commonly referred to as EPS, is a closed cell insulation that has been around since the 1950’s. EPS is made of 98% trapped air and only 2% plastic, making it an efficient insulator with a small amount of raw material.

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. But some closed cell foams, like Tiger Foam’s E84 Closed Cell formula, have even higher ratings that go up to almost 7 per inch. This higher rating makes closed cell foam better at keeping heat in or out of a structure.

How thick does closed cell foam need to be?

Closed cell spray foam should be 4- to 5- inches on the ceiling and 2- to 3-inches in the walls. This might come as a surprise to you, but honestly, this is all the spray foam it takes to get the biggest bang for your buck with the air seal and thermal resistance needed for certain areas of the home.

Does closed cell foam need a vapor barrier?





Closed-cell spray foam insulation, on the other hand, is completely moisture-resistant. Because it creates a moisture barrier on its own, there is no need to install a separate vapor barrier as long as a sufficient quantity of insulation has been implemented—typically around 1.5 inches thick.

Do you need a vapor barrier with open cell foam insulation?

Open cell spray foam is not a moisture vapor barrier, and will allow moisture to pass. So, if you’re considering spraying foam to the roof deck of your new or existing home, you want open cell. If there’s a roof leak, water will pass through the foam, and you will quickly be able to find your problem.

Which is better XPS or EPS?

In general, when comparing EPS and XPS board densities, the compressive strength of XPS is greater than that of EPS. For EPS to achieve the same compressive strength as XPS, the density of the foam would need to be increased, often resulting in a greater thickness of board being required.

Is EPS insulation any good?

EPS is an extremely durable material
Expanded polystyrene will last the lifetime of any building where it’s installed. The thermal performance of EPS does not degrade over time, meaning the U-value you first achieve with EPS will not change.

Is EPS and XPS the same?



EPS (expanded) and XPS (extruded) are both closed-cell rigid insulation made from the same base polystyrene resins and manufactured differently, EPS is beads that are molded or cut into various sizes and shapes while XPS is extruded sheets.

What is the R-value of 4 inches of closed cell foam?

This microscopic difference in the two products creates a dramatic difference in performance. Closed cell spray foam has an R-value of R-7 per inch. In comparison, open cell spray foam has an R-value of R-3.8 per inch.

Is closed cell foam insulation worth the cost?

Closed-cell spray foam is the king of the insulations when it comes to both R-value per inch and cost. Nothing else comes close, really. Unlike its open-cell cousin, closed-cell spray foam is not vapor permeable and will not hold water. This makes it an excellent option in case of water intrusion.

HOW MUCH DOES closed cell foam expand?



approx. 1 inch thick

Closed cell foam expands to approx. 1 inch thick when applied. Open cell foam expands to a whopping 3 inches thick. It’s this ability to expand that allows the foam to completely fill every crevasse and open space it encounters, providing a superior air seal that far outperforms other insulation types.

Where should you not use spray foam insulation?

For areas too close to ceiling light boxes:
You should not use spray foam to insulate areas around recessed ceiling canister lights. If you spray too close to the top of ceiling light boxes, you can trap heat and increase the risk of a fire.

Is EPS foam a vapor barrier?

A: No, although EPS has a low water vapor transmission rate, EPS is not a vapor barrier. Rather it “breathes”, and therefore does not require costly venting as do other insulation materials, which would otherwise trap moisture within walls and roof assemblies.

Does spray foam create moisture problems?



While the benefits of spray foam are multifaceted—it can reduce energy costs, increase a home’s structural integrity, create a moisture barrier and prolong the life of an air conditioning unit—it can also cause problems.

Will closed cell foam rot your roof?

Well, will it? It’s a reasonable question to ask, considering that some homes with open-cell spray foam insulation installed on the underside of the OSB roof sheathing have reported moisture problems. There’s also a pretty reasonable answer to will spray foam will rot your roof: No spray foam will not rot your roof.

Is spray foam insulation in attic worth it?

A properly done spray foam job not only insulates but also greatly reduces the air leakage of a home. But that only works if the installer can get it into the places where most of the air leakage happens. In an attic, the eaves are one of the most critical places to get good coverage with the foam.

Will closed cell foam stop condensation?

Spray foam insulation minimizes moisture-related problems caused by random air leakage because it fills all the cracks and crevices where air enters. Spray foam insulation can effectively seal roofs and other spaces where condensation is more likely.

Will closed cell foam stop water leaks?



Closed cell spray foam can keep that water out, but that’s not a fix because it isn’t going to magically disappear or dissipate. Closed cell is water impermeable, which makes it great for a lot of projects, just not this one and here’s why.

Can exterior foam insulation cause mold and moisture problems?

The benefit of foam insulation in the exterior wall when it comes to moisture is it doesn’t provide a favorable material for mold to grow in and most foam products contain no food value for mold. Foam insulation also creates a needed air seal that will keep your home comfortable and energy-efficient.