I've recently experienced a situation where an MgO board supplier is doing anything BUT professionally responding to well documented problems in the materials that he supplied. The buyer has asked for Warranty service, but is getting nothing but finger pointing by the seller. The problems include boards that curl when they are removed from the original stack and left out on a floor for a day, pre-existing cracks in the boards, boards that crack after installation, and what appears to be shrinkage of the boards after installation. Has anyone else experienced anything similar or is this situation particular to the boards that the buyer purchased? Does anyone know the cause of such problems? Thanks!

RenoArch

If your mgo board longer than 2440mm,it is easily curl after stack on the pallet.There are three main factors cause the curl
1.Manufacturer's base board is too old that already curled.
2.Long time stack on the pallet.
3.big temperature difference.

About the crack,you can drill before you fix the boards on the steel frame with screws,and keep the screws a little bit far from the edge of the board.It is effective to avoid the crack.

You mentioned shrinkage after installed,I think your local temperature is cold.Expansion and Shrinkage can't be avoided due to mgo's physical characteristics.So when you install the boards,you should leave about 10mm between two boards and use the elastic joint compound(elastic putty) in the connection.It can avoide Expansion and Shrinkage obviously.

Hope it help u.