Expert: Bruce E. Johnson - 3/2/2010

Question
I am gearing up to install mosaic stone tiles on a living room wall (approximately 170 square feet).  The wall's construction is steel studs with gypsum wall board.  The tiles we are installing weigh approximately 5.5 lbs/square foot and the wall height is 7'-4". I contacted USG and they stated that the gypsum board will typically hold any material up to 10 lbs/sq. ft in a dry area such as a living room (where the real threat of failure is due to wet areas delaminating the gypsum paper).  My concern is if I am placing too much of a load on the metal studs and would that affect a floating wood floor (floating over a concrete slab) below the wall base? Knowing this is a uniform load and not a point load gives me some comfort in that approximately 45 lbs are bearing down on each linear foot spread over 20 ft in length.  Am I worrying too much here about the studs and floor carrying the load or should I look to reinforce the wall?

Answer
Hi Sean, I build a lot of commercial bathrooms which often involve tile over gypsum board and steel studs.  Weight has never been an issue that I can remember. The weight is mostly verticle and once grouted the tile layer becomes solid and actually puts little stress on the wall, in fact it reinforces the wall to some extent.  I hope this information helps, please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com