I'm hearing and reading a lot about magnesium board as the skin for SIPs. What I have found out is that it is good as a 'stressed skin' member, not 'structural'. For companies selling and installing SIPs, I would have to think that this distinction is extremely important for consumers to be aware of! I am also hearing that there are issues with cracking as the MAG board is not structural, it cannot withstand the forces and starts to crack. That cannot be good long term! If MAG board was structural, we'd see every stick construction project abandon OSB and use it. We're not seeing that happen. Plus in our market, a 4X8 MAG board is $32 per sheet, OSB is $8/sheet. So how can MAG boards be used in SIPs cost effectively? I don't know or understand. Plus when we look at the whole purpose of this website/forum, it is about GREEN building. I can't see how a product extracted in China (known for dubious product quality), shipped via truck to a sea port, put on a freighter for a trans Pacific Ocean shipment, then offloaded and shipped again by rail or truck, is truly GREEN? Meanwhile our North American industries can supply us with OSB from purposefully grown and harvested trees using USA or Canadian workers, keeping an industry here vs. outsourcing it. I know I titled this discussion to find out from everyone if MAG board SIPs are truly structural and truly safe? If you can help me and answer this so I know with FACTS, I would appreciate it. From what I am being told it appears the answer is no and I'd like to know what other points I am missing? Plus all the press about severe issues with MAG drywall sheets leaves me to wonder further. I look forward to constructive information. thanks.

The sheetrock problem is not related to mag board in any way.
As I understand it (and I have reason to understand it)

The problem with the sheetrock stems from the use of FGD (flue gas desulphurization)

When high sulphur coal is used they inject lime (Calcium Carbonate) to miticate the sulphur dioxide emission.  The Ca attaches to the So and forms CaSo3 (Calcium Sulfide) And to some degree (related to the methodology) CaSo4
Gypsum is CaSo4 which is what sheetrock is made from.  CaSo3 can be calcined further to create CaSo4.
Naturally occuring Gypsum is normally used where available but the dirty little secret is that FGD is used in the US as well .  Right now the finger is pointed at the imported Chinese product--and rightly so.  The future will see the finger being pointed at the US companies doing the same thing.

There is no MGO (magnesium oxide) in the equation in this issue.  MGO is what is the base for Mag Board.
The structural conscerns are hopefully address by certification testing in the US???

 I actually talked to Paul the other day and I mentioned something to him that has happened to some friends of ours. The seams between the two panels where they have been taped and mudded keep cracking, not the actual panel. Luckily it happened while still under construction so they just added a layer of drywall to the interior. The supplier has informed us that he has it figured out now but it leaves me a little skeptical.

 It is a new build out in the country so it could be caused by a number of things such as foundation settling, high wind loads or I'm not sure if the heat was on during our cold spell but I thought maybe the mud wasn't rated for -20 C. Other than that I wondered if it could be the panel flexing under load but it is a single storey ranch and they sure seemed strong to me???

 This has me looking towards OSB SIPs now thinking I should be able to get them cheaper (given the cost of OSB vs. Magboard sheets) but so far they are about 40% less/sq foot.

Maybe I'll just stick frame it...... (just kidding)

Sean

I am a partner in two companies MagBoard and MagWall we have testing on both... MagWall is the strongest SIP panel on the planet..MagBoard has been tested and our plant in China is the only Manufcturing Mill of Mgo board certified and QC'd by Intertek...my partner and I probaly have more knowledge and experience on this subject then anybody else in North America  and we sell our board a lot less then $32.00 and if you build the way we do you will have no problems with cracking or anything else...there are a lot of folks out there who buy boards from brokers in China and pawn it off as tested board we are the only ones in the US who owns the plant in China  with a on going QC program that is very strict... assays.. core samples.. moisture testing ext..

Magdaddy;

do you have a recognized approval to attach Hardie siding?

Where did they get their MgO Sips make sure the borad and the panel have been tested and the plant in China is certified or you wont know what your getting..there are over 800 plants in China making MgO board and probally only 3 that I would buy from

MagDaddy, I'm just curious as to your reasoning for locating your plant in China? Is it for labor economics? or availability of raw materials? Maybe it's easier to build a plant there with friendlier regulatory bodies? Or energy costs? Just curious.

is it you don't know or don't want to say?

You dont need to put Hardie on shoot it with MagPlus our MgO stucco chemical bond can't get it off with a hemmer and chisel

I want a bead board siding look

Three reasons

* high quality raw materials ..they have mountains of it

* expertise.. making boards for a hundred years

* labor... 6 dollars a day... and there happy for a job.. we also give them good perks... we are now putting one of our guys over there to help with management

hardie sucks..why would you put hardie on a superior product

Thats a great answer, I guess your all  hype and no credability

If your married to hardie put it on the same way you would on OSB

So your answer is to apply an inferior produt to another inferior product is the same approved method of attachment to Mag Board?
sounds like you don't have ducks in a row yet, these are simple questions you will need to address if you plan to move your product.

You will need more than "ITS FANTASIC STUFF"

Thanks for the response, MagDaddy. I read a while back that making Magnesium Oxychloride boards is pretty labor intensive. Is that really true? And, do you use a fiber reinforcing element? Since MOC is pretty neutral, it doesn't degrade e-glass or s-glass the way that portland cement does.

And, let me say that I have a real hardon for Magnesium Oxychloride. It is exceptionally strong, and Sorel cements bond to just about everything, unlike portland cements that work by encapsulating reinforcing members. But I also know the history of MOC additives for portland cement that really tarnished the reputation, and the efflorescence issues with earlier Sorel cements.

GeorgiaTom.. what I am trying to do here is educate you on the benefits of MgO board and anyone else that is interested and not make the same mistakes I did 6 years ago and buy crap board and if you want to compare credentals call me.... Timothy J Faust   775 338 2252 www.mag-board.com or www.magwall.com

No thanks if I want insults I'll buy a used car from Don Riccles, If you dont have the answer s, you just don't have them....the simple answer is "I don't know" no need to throw around insults..it won't win friends and influence people

 Whoa, that was a little harsh, and in fact I do drive a Model A.

I wasn't trying to knock the product, I am really interested in the Magwall, in fact your links look like the same ones I was considering up here in Calgary. I'll agree they are super strong and don't burn, believe me my friend tried on the scraps. It is something that most people aren't used to and it takes time to build confidence sometimes causing people to step backwards. This is a huge investment for a homeowner and I want all the details before I spend half a million on a house.

 If I have to drywall the inside and I know ahead of time, I'm okay with that but I don't like surprises. I still want to see what the finished interior walls look like as compared to a regular wall.

 I am leaning towards the Magwall but responses like that will push me as well as others away. Play nice.

Sean

I;m cool it seems GergiaTom woke up on the wrong side of the bed..but if you have any questions or want to see finished product in the field we have a MagWall plant in Edmonton that I can arrange for a tour and my partner I assure you can get you comfortabe with the technology..if you are going to build a house I will put our panel up against any and all...do your self a favor and call Gordy @ 780-760-1270

  PS nice ride... you should bring it here to Reno for Hot August Nights