Frequently Asked Questions

Q: What is extremegreen?

A: extremegreen is a high-density structural magnesium oxide cement board designed to replace plywood, OSB, fiber-cement board and interior and exterior gypsum based sheet building products.

Q: What is extremegreen made from?

A: extremegreen is made from Magnesium Oxide (MgO).

Q: What is Magnesium Oxide?

A: Magnesium Oxide (MgO), is a naturally occurring inorganic mineral that is mined from the earth much like Portland cement.

Q: Is extremegreen structural?

Yes, extremegreen can be used in place of plywood, OSB, fire-treated plywood, fire-treated OSB, exterior gypsum board and interior gypsum board.

Q: Can extremegreen be used externally?

A: Yes, extremegreen can be used internally or externally

Q: Where is extremegreen most commonly used?

A: extremegreen is most commonly used as exterior sheathing, interior wallboard, subflooring, ceilings, roof decking, fire-resistant wall and subfloor assemblies, tile backerboard, siding and trim.

Q: What sizes is extremegreen available in?

A: extremegreen is available in 3’ x 5’, 4’ x 8’, 4’ x 9’ and 4’ x 10’.

Q: What thicknesses is extremegreen available in?

A: extremegreen is available in 1/4”, 1/2”, 5/8” and 3/4″.

Q: Is extremegreen sheathing expensive and how much does it cost?

A: extremegreen is a high-performance building material, so sheet for sheet it is more expensive than traditional gypsum board, but it is fire, water, mold and insect resistant.

extremegreen™ is a far stronger, high impact product and requires fewer layers than gypsum, fire treated plywood or OSB in fire-rated assemblies, thus saving money in material in labor. Significant savings are also achievable when it comes to finishing.  Typically, 50% less joint compound and paint is used to achieve a Level 5 finish.

Q: extremegreen flooring expensive and how much does it cost?

A: extremegreen flooring outperforms most other floor sheathing products on the market and can save 40% – 50% when compared to poured concrete. It also eliminates the need for lightweight gypsum use in mid-rise, high-rise and multi-family construction projects.

Q: How do you install extremegreen?

A: extremegreen is installed in a similar fashion to gypsum board, plywood, or OSB.

Q: Can you nail extremegreen?

A: extremegreen can be nailed or screwed.

Q: Does extremegreen feed mold?

A: extremegreen does not rot, mold or feed mildew and has a 0/0/0 mold rating.

Q: Is extremegreen flammable?

A: No, extremegreen is non-combustible and is Class A fire rated, with a 0 flame spread and 0 smoke developed rating. No other plywood, OSB or gypsum based product can claim this.

Q: Is extremegreen heavy?

A: No, a ½” sheet of extremegreen weighs approximately the same as 5/8” gypsum board – +/- 2.4 pounds per sq. ft.

Q: Is extremegreen people safe?

A: Yes. extremegreen is completely non-toxic.  It is manufactured from 100% natural inputs and does not off-gas. It is exceptionally good for Asthma or chemically sensitive people.

Q: Is extremegreen contractor friendly?

A: Yes, and the dust generated when cut with a circular saw is non-carcinogenic. extremegreen does not contain known toxins such as formaldehyde, crystalline silica or fly ash.

Q: How do you cut extremegreen?

A: extremegreen can be scored and snapped like gypsum board, or you can use a circular saw.

Q: Is extremegreen an approved building material?

A: Yes, extremegreen is a listed and certified building product and complies with the 2009, 2012 and 2015 International Building Code and International Residential Code.

Q: How do you finish extremegreen?

A: extremegreen is taped, mudded and painted in a similar fashion to gypsum board.

Q: Can you achieve a Level 5 finish with extremegreen?

A: Yes, a Level 5 finish can be achieved with one coat of extremegreen Primer and one coat of top coat.

Q: Is extremegreen termite proof?

A: Yes, extremegreen is completely resistant to all wood boring insects.

Q: Is extremegreen waterproof?

A: extremegreen is impervious to water, both fresh and salt. Being cementatious, it does however absorb some water.

Q: What happens when extreme greengets wet?

A: Nothing. It dries out and is unaffected.

Q: Is extremegreen dimensionally stable when wet?

A: Yes, very.

Q: When should extremegreen be used?

A: extremegreen should be used wherever there is a need for a fireproof, mold proof, insect proof, waterproof and high impact alternative to gypsum board, plywood, OSB or fiber cement board.

Q: What kind of screws do I need to fasten extremegreen?

A: We recommend powder coated, yellow zinc or stainless steel #10 screws for fastening into steel framing or a #12 screws for fastening into wood framing.

Raised nibs under the head of the screw help countersink the screw beneath the surface of the board and deliver a superior finish. We do not recommend traditional bugle-head gypsum screws.

Q: Is pre-drilling necessary?

A: No, not with the recommended screws.

Q: Do I need blocking to hang pictures when using extremegreen?

A: No. You can hang practically anything off extremegreen with no additional blocking needed. (See Data Sheet for maximum capacities).