Gypsum Ceiling BOard; Gypsum wallboard

[ajk1]

I am reviewing a set of drawings for a proposed new house on which is written for the ceiling construction: "1/2 inch gypsum ceiling board OR 5/8 inch gypsum wallboard".

Question: what is the difference between "gypsum ceiling board" and "gypsum wallboard"?
Is gypsum wallboard weaker than gypsum ceiling board, such that it is required to be a greater thickness when used on the ceiling, than gypsum ceiling board used on the ceiling?

 

[Splitrings]

I had never heard of it either. It is available. 1/2" ceiling board limits deflections to the same as 5/8" wall board.

http://www.nationalgypsum.com/resources/construction-guide/NGCGypWallBoard.pdf

 

[ajk1]

Thanks splitrings for the speedy response and interetsing link. Much appreciated. The link that you sent me refers to it as special "high strength" product. To me that implies that normal 1/2" ceiling board is not such high strength. And if that is the case, then the drawings should be specifying this particular product if that is what is wanted. Do you agree?

 

[Splitrings]

I just looked at astm c1396, section 12, and it is for ceiling board. It does have a considerably higher bending stress than does wall board. Based on this I would specify it needs to meet or exceed this astm.