mud pan- question about recommended 2x10 framework

[yakman]

Hello all,

I've torn out my old shower, moved my p-trap, and relocated/installed new shower valve based on my planned install for an all tile shower. I've read where the recommended "box" to be formed along the bottom of the shower is from 2X10's cut and nailed between the existing studs. Easy enough, however along the back edge of my shower to be, my existing plumbing takes a turn and has a t-fitting where the outside vent attaches to it. It runs down from the roof between two studs on the back wall, through the lower framing stud on the back shower wall and T's into the drain as it exits the shower area.

I'm puzzled as to what to do with that space where the vent pipe is when I'm building my 2x10 box around the shower. The round hole for this vent pipe actually cuts the front edge of the framing rail along the floor if you can picture that. I have 2 inches to the left of the pipe and about 12 inches on the right side and it backs up against an outside wall.

What do I do in this case? It's my understanding that the "box" will hold the mud and should not/cannot have any openings around the perimeter?

Thanks for your help.

Doug

[jadnashua]

The blocking does two things...it give you an edge to hold the 'mud' and it gives you a place to tack the liner up the wall.

The best place to research building a shower is www.johnbridge.com. There are other ways to do this, and the one I like is to use Kerdi. This makes the entire shower - walls, floor, etc., all waterproof right under the tile. Check out www.schluter.com and view their videos on Kerdi shower construction. You wouldn't need the blocking, can use drywall on the walls instead of cement board, and will end up with a better shower. The conventional one works fine, too.

[yakman]

Kerdi systems eh? I just realized that these trays could be cut to my dimensions. I previously thought that your rough-in had to match their dimensions to use that system. I should be able to purchase a Kerdi system at HD. I've seen another preformed system from Tile-Redi. Their 48X42 preformed pan is $749.

[jadnashua]

To save money, you can still make the pre-slope out of deck mud. that mode may be required if it is a non-standard shape, or the drain in not centered. For best results, you should try to ensure you cut one of their preformed trays equally, to keep the height the same on all edges. Now, if it is not a major difference, you probably won't notice the bottom row's bottoms aren't even all around (which you could do with a mud pan, or use the full-size preformed one). The preformed curb that is included with the kit is quite wide and high. It works fine - people are surprised how robust once thinset into position, but again, some pavers, or bricks, or stacked 2x4's work well on a subfloor and will save some money. SO, to save some money and not compromise things in any way, you can just get the Kerdi material and drain. The drain comes with some preformed corners. You may also want some kerdi-band, but you can just overlap the sheets instead of using the (thinner) band material...functions the same. The band is nice because it is thinner, but except for a very thin tile and a small notch trowel, you'd never notice the overlap verses the band.

HD can probably special order a Kerdi kit, but there are much faster and cheaper ways to obtain one if you can't find it locally in stock. Check the www.johnbridge.com website....they have an on-line supplier that has good prices, and really quick delivery linkable on their store.

I installed a kit about a year ago, and later had an opportunity to take one of their classes. I believe in the system...it works. In class, they had a cardboard box that they covered with Kerdi using thinset. It sat as a drink cooler all day, for months, with ice, water, and drinks in it. The cardboard never got damp...impressive. A shower dries out much faster, since you don't have the cbu or deck mud to absorb moisture...it is stopped right underneath the tile. Their drain is a pleasure to use...the receptor can be moved a bit to help center it right where you want it and, it is square. Much easier to fit the tile up to. In the shower I did, I used 2x2 mosaic, and just cut 4-tiles out of the sheet...fit perfectly around the drain. SOOO much easier than trying to fit them around a fixed, round drain.