2x8 Floor Closed Cell And R21

If you have 2 6 studs you can do 1 5 inches of closed cell and put r13 batts behind it for an extremely good envelope.

2x8 floor closed cell and r21.

Now that you understand insulation r values you can make sure your home is properly insulated. Three inches of spray foam has an nrc of 0 70. Open cell has an r value of 3 7 and closed cell has an r value of 6 5 based per inch of installed spray foam. R 3 2 polyisocyanurate rigid foam insulation board r matte plus 3 thermasheath 3 is rigid foam r matte plus 3 thermasheath 3 is rigid foam plastic thermal insulation board.

Enjoy better floor to floor climate control in your home by installing ceiling insulation. It s made of environmentally sound closed cell polyisocyanurate foam bonded to a durable white matte non glare aluminum facer and a reflective reinforced aluminum facer. If you want to install spray foam in a stud wall and price is no object then it would seem to make sense to specify closed cell spray foam right. Folks need to remember though that if you are relying on the closed cell foam for its vapor barrier properties many foams require at least 1 5 inches to be considered a sufficient vapor barrier.

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. That means if you used foam it green closed cell which is r 7 per inch it s r value for a 3 5 deep wall cavity would be r 24 5. Deciding whether to use r 19 or r 21 insulation is largely a matter of weighing immediate costs over long term savings. It s expanding properties ensure that it covers every little crack and hole but even with that ability it still needs to be installed correctly.

Rmax r matte plus 3 1 2 in. The damp foam can then transfer the moisture to rafters and decking materials leading to rot or leakage. While the denser closed cell variety does not readily absorb moisture open cell foam can draw it in like a sponge. The closed cell acts as a moisture barrier when cured is hard can be used indoors and can act as a structural reinforcer.

The insulation is blown into the wall or attic one layer 1 at a time. The closed cell also dampens sound but since it cures hard it can separate from wood frames causing sound transfer channels. Depending on the prices of each type of insulation and the total square footage of the construction project it may make more sense financially to install the more expensive insulation because it will save you money in the long run.