Adequate floor support for new shower?
I am remodeling a second floor master bath. I am planning to install a new shower with 12x12 porcelain tile, a tiled floor, and a glass enclosure on two sides. The shower is 52"x33" with 8 ft. ceiling, so two walls, the floor and ceiling are 81 sq ft. I estimate that the tile will weigh about 500 lbs. not counting the thinset and grout and the enclosure a few hundred pounds, so the total weight of the new shower could be 800-900 lbs. Does that sound about right?
The current shower has an acrylic base and shower enclosure (I think it's acrylic or glass) and thin 4x4 tiles on the walls and ceiling. So, I am going to be adding lots of weight.
The shower subfloor is 1/2" plywood supported by 3 web truss joists spaced 24" oc. The shower is roughly in the center of a 12 ft. span. Because the span is so short the joists are rated at least L/480 according to the span table.
Even so, I am concerned about the extra weight of the new shower. How do I determine if I will get deflection in the joists from the added concentrated weight? I cannot sister the joists. I could possibly add a strongback or two if I tear out the first floor ceiling. Any other thoughts? Thanks.
Last edited by daveofnj; 05-06-2010 at 03:26 PM.
Reason: forgot something