AskCodeMan

I am adding a second bathroom and have a question regards type of drywall to use. it will have a enclosed shower tiled to teh cieling and a standalone tub 3" from wall. can I use green board in entire bathroom including area's getting tiled? House is in FL and is CBS construction.

Thanks in advance

"Green board", which is "moisture-resistant" gypsum board (MR Board) is not suitable for use on ceilings (without special changes (supports closer spaced that regular gypsum board (i,e, regular "drywall").

MR board is not "water resistant", it is only "moisture resistant" - and there is a big difference between the two. As such, MR board is suitable for use behind ceramic tile in "dry" areas, such as tiled walls in a bathroom which are not behind a sink, not around a tub with a shower, not in a shower - but can be used on walls around a tub without a shower.

Basically, MR board is not suitable for use where there is water.

"Water resistant" gypsum board is available for those areas which get wet from water, such as behind a sink, around a tub with a shower, and for shower walls.

However, the best type of board to use on shower walls is a cementitious board (often called "cement board"), such as Durock (by US Gypsum) and PermaBase (by National Gypsum), however, there are other brands available too.