QUESTION

Stone Installation Specification - Is there a specification for what needs to be prepped for installing marble in the shower and where do I find it? What needs to be on the green board for a water bearer?

ANSWER

ANSWER - The TCNA (Tile Council of North America) publishes an Installation guide that can apply to marble tile.  MIA (Marble Institute of America) publishes a manual and discusses wet areas briefly.  For their information you can go to the CTaSC web site to Expert Answers and find Industry Associations in the Resources column.

First of all you need to make sure you are aware that some stones are water sensitive and are not recommended for wet areas.  Some common problems could be that the stones can stain and have some degree of deterioration.  You can assume that all stones will tend to lose its shine from the polish caused by the constant exposure to the water and cleaning agents.  Granites are much more resistant than marbles.  Also Polish stones are not recommended for the wet area floors due to the chances of slipping.

People do install stone over green board (water resistant wall board), but it is not considered a good method of installation.  It will deteriorate if exposed to moisture which can reach it from the front, side or back.  Also it isn’t considered as structurally sound for a long lasting installation.  Considering all the mold litigation, it is further not recommended.  If you get a moisture problem and the green board gets wet then you are likely to get mold.  It is worst with wall boards because it is an ideal source of food for the mold that then further perpetuates the problem.  It is always recommended first to do a cement mortar installation and second best would be to install over cement backerboard.

If you choose to go ahead and install over green board, then several manufactures of installation products make products for this type of application.  Most important is to have a vapor barrier over the studs, make sure all transitional joints are sealed with a caulking, and apply a liquid or troweled applied waterproof membrane that you can use to paint over the surface of the green board and then thinset the marble to it.  You can go to the Resources column in Expert Answers of my web page to Installation Products for some of those manufacturers.

Good Luck!
ANSWER - The TCNA (Tile Council of North America) publishes an Installation guide that can apply to marble tile.  MIA (Marble Institute of America) publishes a manual and discusses wet areas briefly.  For their information you can go to the CTaSC web site to Expert Answers and find Industry Associations in the Resources column.

First of all you need to make sure you are aware that some stones are water sensitive and are not recommended for wet areas.  Some common problems could be that the stones can stain and have some degree of deterioration.  You can assume that all stones will tend to lose its shine from the polish caused by the constant exposure to the water and cleaning agents.  Granites are much more resistant than marbles.  Also Polish stones are not recommended for the wet area floors due to the chances of slipping.

People do install stone over green board (water resistant wall board), but it is not considered a good method of installation.  It will deteriorate if exposed to moisture which can reach it from the front, side or back.  Also it isn’t considered as structurally sound for a long lasting installation.  Considering all the mold litigation, it is further not recommended.  If you get a moisture problem and the green board gets wet then you are likely to get mold.  It is worst with wall boards because it is an ideal source of food for the mold that then further perpetuates the problem.  It is always recommended first to do a cement mortar installation and second best would be to install over cement backerboard.

If you choose to go ahead and install over green board, then several manufactures of installation products make products for this type of application.  Most important is to have a vapor barrier over the studs, make sure all transitional joints are sealed with a caulking, and apply a liquid or troweled applied waterproof membrane that you can use to paint over the surface of the green board and then thinset the marble to it.  You can go to the Resources column in Expert Answers of my web page to Installation Products for some of those manufacturers.

Good Luck!