I need to pour a concrete base for a shower that will have a tiled floor. The subfloor is 3/4″ OSB and the floor will be tiled. Can you give me advice on the concrete mix, minimum thickness and the sequence of materials that you would use (rubber barrier, reinforcement mesh, etc.)
Thanks for your help. I’m STILL new at this stuff.
Replies
Novice:
Constructing a shower without a proper idea of what to do and how to do it can be one of the biggest disasters you have faced. Doing it wrong can cause severe structural damage to the framing, flood the area, and cause the area to be a mold magnet. Beware. Get the Tile Council's book on tile and go the Nobel Company site or go to John Bridge's web site for information.
I don't have the time today to write an article for you on the subject, but here are a few pointers:
1. Pre-slope. This is a slab of mud (not mortar, not concrete) than slopes from the walls of the shower to the drain at the rate of a quarter inch per foot. Use mud, 5-1 mix sand to portland. Nail up 1x1 screeds along the perimeter as one half of the guide and use the top of the two part shower clamping drain as the other. OSB, tar paper, diamond lathe, then mud. Mix the mud very dry.
2. Use a 2 part clamping drain specifically designed for showers.
3. Use PVC or CPE membranes bought at a tile or masonry store specifically designed for showers. They need to be folder at inside corners, and wrapped up and over the curb. Along the jamb you need to use specially designed corner pieces. Use the manufacturers own glue. No nails except at the top and the outside of the curb. The membrane has to be about 4" above the curb and blocking has to be installed all along the walls to accept it. No nails except at the top. The studs have to be knotched to accept the membrane so there is no buldge at the bottom, or all the studs need to be firred out so the backerboard goes up and over the membrane.
4. Setting bed is same 5-1 mix at the same quarter inch per foot slope.
5. Curb is constructed with mud, not backerboard which has to be nailed. Did I say no nails except at the top of the membrane above the curb?
6. Backboard is OK for the walls, but put plastic behind it or waterproof it with a brush on rubber liquid like Laticrete 9235. It needs to be installed after the preslope and membrane so the final setting bed locks it in place. I like to apply 9235 just for s h i t s and grins to bullet proof the shower walls.
7. Don't tape the backerboard seams if you waterproof the backerboard, and don't tape them at all until you start laying tile. Prevents speed bumps.
All for now, others will chime in
Regards,
Boris
"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934
I'll chime in...listen to Boris. If you're new here, you don't know his competence, but it's high...as good as you'll find on this site about tile. I don't think this is one of the easiest areas for novice to earn his stripes.
I did the same thing, its not hard.
Go to Home depot or lowes. They is a book called "Setting Tile" by Michael Byrne publish by the same people that run this forum.It has all the steps and information you need to complete the job. also do a search on Michael Byrne, he has a wep page on the same subject. Its not hard just follow details.
Michael's book is excellent. Do not, repeat do not, following Home Depot's Tiling 1-2-3.Regards,
Boris"Sir, I may be drunk, but you're crazy, and I'll be sober tomorrow" -- WC Fields, "Its a Gift" 1934