# MgO board



## bkvanbek (Jan 31, 2014)

Has anyone used MgO board? I used it on my new house, Magnum Board is the brand I used. The reasons I used it are; No paper so it won't mold, much much stronger, two layers of fiberglass. Half inch and you can stand on the back side when on trusses 2' oc.

I always hated gypsum; weak, heavy and falls apart and molds if it gets wet.

It is tougher to cut, of course it is much stronger, I wouldn't use paper tape or water soluable mud as that would defeat the purpose of mold resistant. Magnum Board recommends fiberglass tape and Rapid Set One Pass. 

I distribute BuildBlock ICFs and may want to sell Magnum Board, interested in opinions.


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## icerock drywall (Aug 16, 2012)

bkvanbek said:


> Has anyone used MgO board? I used it on my new house, Magnum Board is the brand I used. The reasons I used it are; No paper so it won't mold, much much stronger, two layers of fiberglass. Half inch and you can stand on the back side when on trusses 2' oc.
> 
> I always hated gypsum; weak, heavy and falls apart and molds if it gets wet.
> 
> ...


I would use fibefuse...and I have seen mold on durarock and glass...mold will grow anywhere


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## Ancient Rocker (Jul 25, 2009)

I did a little research and it sounds promising. Can you really cut 1/2" with a utility knife blade? What is the approximate cost per sheet? How heavy is it? Did your hangers or tapers give you any feedback? I would love to learn more from you rather than the manufacturer.


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## icerock drywall (Aug 16, 2012)

Ancient Rocker said:


> I did a little research and it sounds promising. Can you really cut 1/2" with a utility knife blade? What is the approximate cost per sheet? How heavy is it? Did your hangers or tapers give you any feedback? I would love to learn more from you rather than the manufacturer.


I like what you said... I have done skim coating to durabond and on the first job I got hair line cracks like a plaster job. so I had to use 36'' rolls of fiberfuse to fix it ...so will this also make hairline cracks because there in no paper on the face?


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## schaefercs (Jul 10, 2008)

We used MgO on a 27 unit commercial job for tile backer on both walls (1/2) and floors (1/4). First time using it and if would use it again.

It cut pretty well with a utility knife, easier than other tile backer products. 2 or 3 scores and it will snap right off. Small cut offs were a pain, though. 

Although I don't remember the exact pricing, I think we were around 7-8 bucks a sheet. We got a pretty hefty discount buying in such a large quantity. We were only able to source MgO from one dealer locally. Not sure how it is in other areas, but availability may be an issue.


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## bkvanbek (Jan 31, 2014)

A carbide cutter for cement board works better than a utility knife. A 4" grinder with a diamond or abrasive disc cuts fast.

We found that a 20ga steel stud would strip before a black drywall screw would counter sink, so we had to drill a dimple for the screw. Not an issue with wood studs.

The mud, OnePass, sets fast but does not need a second coat. Any gaps at the joints need to be completely full to prevent cracking.


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