What Does Foam Insulation Weigh

Closed cell polyurethane foam used in interior applications (also sometimes referred to as mid-density or two-pound SPF) typically weighs between 1.8 and 3 pounds/cubic foot when fully cured.

What is 2 lb spray foam?

2 lb spray foam, when applied at a thickness of 50mm or more, can act as a vapour barrier. They offer the highest R value per inch of all spray foam systems (typically R5. 5-6 per inch depending on the thickness).

Is 2lb spray foam waterproof?

Medium density closed cell foam is water resistant, but not waterproof (2 pound foam). High density closed cell foam can be water proof (10 to 12 pound foam).

What does expanding foam not stick to?

Because of the properties of SPF (sprayed polyurethane foam) it chemically bonds with most substrates; cement, wood, stone, gravel, and brick. However, spray foam will not properly stick to a surface if the construction surface is wet or is retaining moisture.

Where should you not use spray foam insulation?

When NOT to Use Spray Foam Insulation

  1. For areas that are too close to electrical boxes:
  2. For areas too close to ceiling light boxes: You should not use spray foam to insulate areas around recessed ceiling canister lights.
  3. Open-cell spray foam on your roof:
  4. For closed-cavity spaces:
  5. If you have a history of skin, respiratory, or asthma problems:

Is spray foam worth the cost?

Spray foam insulation is typically two to three times more expensive than cellulose or fiberglass insulation. Spray foam insulation does cost more than traditional options, but over time it pays you back in energy savings, and you can’t really put a price on the comfort of your family.

Can you spray foam around PEX pipe?

Stability of the PEX pipe should not be jeopardized providing the Great Stuff™ and Great Stuff Pro™ sealants are applied as per manufacturer’s instructions around the pipe. Adhesion, however, is questionable between any polyurethane spray foam and PEX surfaces.

Should I use expanding foam around windows?

Sealing around windows and doors is one of the most common uses for expanding foam. But the high-expansion stuff can actually push the jamb inward, making them impossible to open. Avoid this by using minimal expanding foam. It’s formulated to fill the space around windows and doors without excess expansion.

How many square feet does a 55 gallon drum of spray foam do?

Now an drum set (two 55 gal drums one part A one part B) of 2# closed cell will produce 4,000-4,500 board feet of foam and a set of . 5# open cell will produce 15,000 board feet of foam but will have more waste due to trimming.

Should I use open cell or closed cell foam?

Due to the lighter density of open cell foam, it will perform much better than closed cell when it comes to sound dampening. The thicker, softer material of open cell will reduce sound waves much more efficiently than that of the tight, dense closed cell foam.

Can you spray foam the underside of your roof?

Open-cell spray polyurethane foam or closed-cell spray polyurethane foam (ccSPF) insulation can be sprayed along the underside of the roof sheathing to provide a conditioned and insulated attic space that can be durable and efficient in all climate zones (see Figure 1).

What are the pros and cons of spray foam insulation?

Correctly installed, open cell spray foam insulation significantly increases the sealed envelope of the home. A better seal means conditioned air stays in and seasonal air stays out. Some of the drawbacks for spray foam is that it is more expensive to install than fiberglass.

How do I calculate how much spray foam insulation I need?

To calculate how much foam you require to complete a job, multiply the square feet of area by the thickness of the foam to be sprayed. If the area is 1000 ft2 and you want to spray the foam 2½” thick, then multiply 1000 ft2 x 2½” which equals 2500 bf of foam required to spray the area.

What is the R value of 3 spray foam insulation?

Open-cell spray foam has an R-value of 3.7 per inch, while closed-cell spray foam delivers an R-value of up to 6.5 per inch.

What are the disadvantages of spray foam insulation?


  • The upfront cost is higher than conventional insulation.
  • Payback period is 2-4 years.
  • It is not generally a Do-it-Yourself project.
  • The installation process is longer.
  • The process could be messier.

Will spray foam support weight?

Years of exposure to the elements can leave walls lacking support and in need of rehabilitation. Spray foam insulation offers many benefits as a structural support option. First, it is lightweight, which makes it a good choice in situations where the weight of concrete would further damage a structure.

How thick can you spray open cell foam?

While both materials can be used as an air barrier (open cell at 3.75” thickness or greater and closed cell at 1” thickness or greater), only closed cell spray foam creates a fully sealed system that can be used as an air and vapor barrier (at 1.5” thickness or greater).

Is 2 inches of spray foam enough?

The thickness of spray foam really depends on where it’s being applied and what you’re trying to accomplish. Closed cell spray foam should be 4- to 5- inches on the ceiling and 2- to 3-inches in the walls.

Can I spray foam insulation myself?

The answer is yes, but drywall needs to be removed before you can install the foam. Spray foam expands rapidly when it is applied to the inside of walls. As you can see, it is crucial to remove drywall before installing spray foam insulation.

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

During the winter, when the sheathing is cold, the sheathing will accumulate moisture. To prevent this type of risky moisture accumulation, cold-climate builders need to install a vapor retarder on the interior side of any open-cell spray foam installed on the underside of roof sheathing.

How much spray foam is too much?

The ASTM E84 tests for most spray polyurethane foams limit the maximum installed thickness of foams to 4 inches or less. The ASTM E84 tests for some SPF products limit installations to a maximum of only 2 inches.

How long does spray foam insulation last?

The International Association of Certified Home Inspectors states that spray foam insulation, wrap tape and housewrap insulation can last for more than 80 years. At the same time, cellulose, loose-fill, foamboard, loose fill and rock wool insulation can last up to 100 years.