Shower drain height?? [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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11-03-2004, 12:43 PM
Great info site!

In process of building my shower pan. I have current slope that I'll need to improve on.
2" pipe sticks up about 12" above floor.(new) - left that way for me to cut as needed.
Outside walls have CBU already glued and screwed on - concrete blocks behind.

Questions as follows:
1) Not clear after reading what height to cut this pipe to initially. Top is a Sioux shower cap. Do I use a level across and cut to current level floor height or higher?
2) Since the CBU is directly on the blocks (felt behind it) there is no method to notch back for liner. I was not aware this should be done at time of installation. It's on - so now I have to figure a workaround as best I can. The bottom section(s) are not installed yet - should I just use adhesive and tack up behind the CBU? I understand it will be somewhat slanted/firred out because of membrane there but I don't have any other solution or idea as to how to handle this. Solutions/ideas??
3) Do you normally use felt paper on top of preslope and below final thick mud? The liner instructions say yes, some articles also I have read same. I guess to avoid abraiding the membrane. Opinions here?

Why did I not find this site before I began!!!!!!!!!!!!!!!


need to register. I did at least register to vote yesterday. 1 for 2

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11-03-2004, 01:18 PM
Is this shower on a slab?

Clamping ring shower drains need to be set so the top of the bottom half of the clamping flange is 3/8" to 1/2" above the subfloor. Look at your fitting to see where the top of the pipe has to be to get there.\

The problem with your installation will be most noticable in the corners of the liner, where it will folded into at least 3 thickness. You could live with it that way, but you'll be regretting it every time you use the shower. You could also chip out the concrete block a little with your angle grinder(about 1/4") where the folds go, and live with the lesser problem (single layer) elsewhere. You could also remove the CBU and start over. Not unheard of, and CBU is cheap(ish). Or, you could convert to to Kerdi. This will involve more chipping of the concrete floor to get the somewhat larger Kerdi drain in, but you will avoid the flared CBU problem, and you will only have to install one mud bed (or repair the preslope you have now). Visit , look at the Kerdi system and think on it a day or 2.

If you still go with the liner, we don't recommend the tarpaper between the liner and the preslope or the final slope (setting bed). We do suggest that you caulk the flange before setting the liner. Just watch for squeeze out and don't let it clog the weepholes.

And yes, Henry, you need to register! ;)

11-03-2004, 02:23 PM
Done that - officially on board now!

The thought of chipping away at the block makes me cring. Think it over and digest that for a bit before I'll commit on it.
**Another thought - since I have it not installed yet on lower part could I not just put a 1/4" piece of plywood firring on bottom, glue to block, install membrane and then cover the whole wall with another piece of CBU? I do foresee one issue this way also - the one wall extends across the full room which would lead to this area being tiled being out more by 1/2". The shower door will be mounted, hinge/pivot side, to this wall. I have yet to actually pick one out but they all do have some kind of tracking on them. Maybe I could use some type of bullnose tile on that side to cover the 1/2" back to the rest of the wall which is drywall. Does this make sense and sound logical for solution?

Think I have down the pipe height to cut at - thanks. I'll use the 1/2" or maybe bit more. Unless I misunderstanding the worst case is I need to use a bit more mud to bring height up - better that than being on short side as I understand it?

How come there is so much info out in magazines, books, you name it and they all have different ideas on the "right" way. I trust you folks here - many others do to so I will trust what's here as My Only Source.

In advance my many thank yous are being extended.

>>On the Kerdi system. If this was a permanent residence for me I would go that route in flash. Plan on moving next spring and want something done right and usable but inexpensive also. Very cool looking system and if I ever do this on another home I may go that method. Make that likely will


11-03-2004, 02:37 PM
Yes, that sounds like a plan. Your first layer of CBU (against the blocks ) can come down to the top of the liner (I'd lose the plywood idea), then your second layer can hang over it down to the shower floor (about 1/2" above the liner). The mud will hold in in place, you can add a few dollops of thinset on the back of the CBU to fill any gap and provide additional support.

Mud caps are trim pieces that can hide the 1/2" thickness difference. It'll look like you planned it that way.

11-03-2004, 03:27 PM
You are fast Bob!

Looking thru info from tile mfg and cannot see anything called mudcap. Same as bullnose and just different expression?

When you say to caulk the flange before putting setting the liner I am unclear. I thought I used the pvc adhesive and glued the liner on bottom to the flange base? I don't and just caulk???


11-03-2004, 03:48 PM
Some tile doesn't come in a mud cap, and it is different from bullnose.

No you don't use the pvc glue to glue the liner to the drain. Probably wouldn't work anyway. Just caulk, 100% silicone is best.

11-03-2004, 04:03 PM
Tile Contractor -- Central Nebraska

Join Date: May 2001
Location: Central Nebraska
Posts: 7,595 Shower Floor Drain


OATEY Product Number:42213 is the 2" or 3" PVC drain with stainless steel strainer.

This is the style Shower Floor Drain intended for use with a vinyl pan liner and is available in plastic (PVC) or cast iron.

This style drain has four components:
Strainer Cover
Threaded Drain Cup
Top Flange
Bottom Flange

The Bottom Flange connects to the trap or trap riser and sits on the subfloor where it should be securely fastened.

The surface of the Bottom Flange should then be temporarily covered with duct tape.

Concrete is then placed throughout the shower floor area, higher at the outer edges and sloping to the center (top surface of the Bottom Flange.)

The duct tape is removed and the vinyl pan liner is installed over the bottom flange with a hole cut through the liner no larger than the size of the drain hole in the flange. It is also necessary to make additional cuts sufficient to expose the threaded bolt holes (3) in the Bottom Flange. A sealant is used to seal the bottom of the pan liner to the top surface of the Bottom Flange.

The Top Flange then bolts to the Bottom Flange clamping the pan liner into place. It is the Top Flange which contains the weep grooves. The bolts should be evenly tightened but not overly tight.

The threaded Drain Cup then screws into the Top Flange where the threads allow for final height adjustment and positioning of the Strainer Cover.

The height to which the Strainer Cover is set then determines the final height of the sloping concrete subfloor. It is however very important to remember that the concrete should actually stop below the surface of the Strainer a distance equal to the thickness of the floor tile plus the thinset to be used. This will result in the surface of the finish shower floor tile being flush with the Strainer.

This style Shower Floor Drain should be available at all Plumbing Supply and Home Center Stores.

This is what some of them actually look like but this is only one version. Manufactured by Sioux Chief Products in Peculiar Missouri.

Last edited by davem : 03-04-2003 at 09:40 AM.

Maybe to avoid doing wrong the word "sealant" could/should be changed in above to silicone caulk to ensure dummies like me don't make a fatal error. Just a thought

Raymond S
11-03-2004, 04:35 PM
The mudcap may be listed as radius cap.

11-03-2004, 08:41 PM
I'm a bit concerned with how you intend to attach the second layer of CBU to the first, Henry. I suppose a fella could run Tapcons through into the block wall, but that's gonna be a bit of work. Actually, I suppose I'm a little concerned with how you attached the first layer. What kinda glue? How many fastners?

Yours is a situation that just cries out for mud walls. You consider doing that? Solves all your problems. And you could leave that first layer of CBU on there if you wanna and if it's attached well.

I think of all the suggestions, Injineer Bob's Kerdi system makes the most sense if you're not willing to take the mud plunge.

My opinion; worth price charged.

11-04-2004, 09:02 AM
CX - fastened with a combination of Liquid Nails construction adhesive and used a power cartridge and drove 2" nails into block. Think it will support a whole house on top of it - guarantee it ain't going anywhere and dread thought of ever trying to take off. Had to remove a small area on bottom due to being to low for liner and took me over an hour (36" x 12" section). Strength on this one not a factor - but you raise great point on doing second CBU on top of it. Suggestions???

Or do I suck it in and spend half a day and strip it all off and fir that wall out say 1/4" and just use the 1 CBU? :bang: