A Real-World Look At Magnesium Oxide Board
Check out this video for a brief rundown of a new multipurpose building material that's making its way onto job sites.
Magnesium Oxide (MgO) board is water resistant, high strength, fire proof, mold proof, and insect proof. It can be used in applications from siding and trim to drywall and tile backer, and comes in thicknesses from 1/2 in. to 3/4 in. It can be easier on tools than fiber cement. In this Tool Tech video from Fine Homebuilding’s tool and product editor, Patrick McCombe discusses the new material and demonstrates how easily screws can be sunk and countersunk into it. He warns that the heads may snap off conventional drywall screws, so you’ll want to use more sturdy screws for this material. MgO board can be cut with conventional carbide-tipped circular saw blades, bimetal jigsaw blades, and oscillating multitool blades for cutting penetrations and the like. You can also score and snap the material without too much difficulty. This product is becoming more prevalent and you may soon see it at a job site near you.
Extreme Green MgO Board
Sold by BlueLinx
Price: 1/2-in.: $1.10 per sq. ft.; 5/8-in.:$1.40 per sq. ft.; 3/4-in: $1.60 per sq. ft.
Senior editor Patrick McCombe has been testing power tools on behalf of national publications for more than 15 years, and he regularly meets with product manufacturers to try out new introductions. In the Tool Tech series, Patrick reviews the latest tools and materials, discusses building technology, and shows time-tested techniques for better, more-efficient home building. Consider becoming an online member to watch other Tool Tech videos.
View Comments
Does it shrink like Azek does? What's the cost? Can it be used where structural integrity is required? Does it give off gasses when it burns? If we breath the dust will our unborn children suffer? Any US manufacturers?
Pretty superficial review. Same comments would apply to Masonite siding, particle board, Chinese drywall in their day. Cuts easy, drills easy, allows screw penetration - WOW !?
Expect a bit more from a subscription site. How long is it water resistant, how about paint retention, sanding, shaping, molding? What about different manufacturers, storage?
Fracture resistance, picture hanger compatibility, edge strength, painting edges.
I’ve sunk MGO in water for months… came out like new, left outside in rainy NW weather, nothing, but… metal attachments, screws, nails is a no no… coated only! Many lawsuits from this…
I agree with Carver above. I read recently that MgO board from China often has chlorine in it. This destroys most screws and nails. That means before purchase it should be shown by the supplier to be chlorine free. They did not show it being sawn. I believe a respirator needs to be worn. There are American and Canadian manufacturers that do not have chlorine in their MgO products.
I have read that it can be "spackled" like drywall and painted with a variety of paints and textures. An 8' sheet can also be bent into a cylinder.
I hope FineHomebuilding shows us a lot more information regarding this product.
MGO is built with Limestone-bonded Portland concrete which remains a 19th Century technology with serious cracking, corrosion and environmental limitations.
What MGO should be made with is phosphate-bonded concrete instead!
What is the R insulation value? Is it available in sheets that have an R value of at least 10 that are reasonable in cost?
I read this article and did a little research. MgO was used from 2010 to 2015 on Danish homes. A study showed that MgO is not good for exterior wet climates because the magnesium salts absorb water and leak salty water to the inside of the wall where fasteners are quickly corroded. See article here:
https://reader.elsevier.com/reader/sd/pii/S1876610217349378?token=8BB87AF033BC6D579A6ED1860FEB4744A6C1DB70B01BE301689195ED273F4296ABFD36243E2A3DF37487DCC881D83655