shower pan liner dam [Archive] - Ceramic Tile Advice Forums - John Bridge Ceramic Tile


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Eric N.
01-04-2003, 07:36 AM

I had one of those greenboard-mastic-tile shower enclosures that they used to build here in Houston. Not anymore....I ripped it out cause it was leaking and now am in the process of rebuilding it along with a tub surround.

This site has been my primary source of info along with John's and MB's books. Thanks for such a great resource.

I have successfully presloped the shower floor and now trying to fit the shower pan liner. I followed the instructions in MB's book on how to do it, but the curb on my new shower goes from one wall to another. In the book the shower curb goes between two jams that are inset from the wall. I'm doing some head scratching because the preformed liner dams do not appear appropriate for my situation.
I noticed the pic on this page shows a curb like mine and the dam looks to be homemade from shower pan liner. I tried doin the same but cant get a patch of liner to form where the wall meets the curb. Please offer some guidance.

I did make one cut over the curb so I could fold the liner. I'll try to attach a pic. Nothing is stapled in yet.


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Eric N.
01-04-2003, 07:41 AM
This is an attempt to post a pic of my shower curb.

01-04-2003, 08:39 AM
Hi Eric, welcome to the forum. I'm glad to see you're a picture guy, It makes things more fun around here. :) Here is a link to some pictures ( John put in the Liberry (you've found the Liberry right?). The blue corner dams will work on a shower like yours (and mine) where there is no jamb. Follow the link in my signature to see some pictures of my project. I used corner dams I purchased off of the Noble website, they are rounded instead of square. Good luck! :)

Eric N.
01-04-2003, 09:13 AM
Thanks Dave. I suppose the preformed dams can be modified or maybe they are flexible enough to fit. It seems that part of rounded part which is 90 degrees to the corner would have to be straightened out to fit up against the wall. Is that right?

01-04-2003, 09:29 AM
No modification needed. Get some paper, scissors and tape and make one. You'll see that if you spin it around about a hundred times, it'll fit right into the corner. :D Click on the image below and you'll go to the Noble website where you can purchase the dams. Mine came in about 3 days. Notice they have CPE and PVC, get the right ones to match your liner! (

Eric N.
01-04-2003, 09:47 AM
I made one. And now I see!
You da man Dave. Thanks.

John Bridge
01-04-2003, 04:34 PM
Hi Eric, We're almost neighbors. ;)

I have some other pictures that I put up for occasions like this. The dam corners I use are more square looking but do the same thing. They work inside or outside, depending on what you want to do.

I think you will need to make room for them though so that the backer board doesn't have to bow out in that area. Notching the studs is a good idea. Here are the pics. The shower depicted has jambs, but by turning the corners about a hundred times, as Dave says, you can get them to work anywhere. ;)

For non-Texans, Eric lives near NASA, which is about 60 miles from where I live.

Eric N.
01-04-2003, 07:32 PM
I went ahead and ordered the noble dams.

I had so much fun with the preslope I'm seriously considering trying to mud the walls. I have a couple smaller walls around my tub which I'm going to try first. If that works then I'll go for the shower. See pic.

John Bridge
01-05-2003, 11:58 AM

I can't see all that well from the picture, but did you leave room between the underside of the tub and the deck for lath, mud and tile? Everything should go under the rim; it should not abut it.

Eric N.
01-05-2003, 02:38 PM
John... I was going to cheat a bit and not mud the deck just the walls. The tub deck is only 4" wide. The rim of the tub is sitting 1/4" above hardibacker.

The attached pic shows a drawing from the installation instructions. I did screw up a little in that is shows the tub should be 1/4 inch above the wood frame. So what I was going to do was add another layer of hardibacker abuting the tub, then a layer of tile abuting the tub.

What do you think?


John Bridge
01-05-2003, 03:41 PM
Yes, you can do it that way, but the other way is best. Can't you raise the tub? Or is it cast iron? If it's cast iron, I'll understand if you do it your way. :D

Eric N.
01-05-2003, 04:05 PM
Yea I can probably raise it. It is an acrylic tub weighs all of 60lbs.

Should I raise it couple inches, get the deck tiled out and then drop it to the right height? And then mud the walls?

I really appreciate your time. Thanks.

John Bridge
01-05-2003, 05:52 PM

This takes a little doing, but on the set-in tub dais (pl?) I do the tub is dropped in and connected after the tile work is done. You have to have access after the fact anyway to get to the connections. I think it would be worth your while to remove the tub entirely. Make a pencil mark around the perimeter before you do and make sure your tile installation goes at least a half inch beyond the mark.

Then, when you set the tub in finally, you set it in a bed of loosely mixed brick mortar and smoosh it down.

Eric N.
01-05-2003, 06:35 PM
That's what I'll do. It might be a little while. My wife and I have not reached an agreement on the tile yet. :shake: Thanks.:bow:

01-06-2003, 10:17 AM
remember the tub is 60# without water! allow room & support for the wt. of the water. (approx. 10# per gal.)

01-06-2003, 10:38 AM
Drain the tub before you move it, all that water is heavy! :D

01-06-2003, 11:26 AM
where were you before i recked my back! the directions didn,t say to drain the tub. hope you know my point was to make allowance for some deflection.

John Bridge
01-06-2003, 07:39 PM
There ARE a few savvy plumbers around, and the savvy ones put about 20 gallons of water into the tub after it has been set in the mud. 20 gallons is plenty in a tub that will hold 50 or 60 when it is used. You don't want to put too much water or you will over-flex the plastic and leave a space between the mud and the bottom of the tub when the water is removed.

When I do it I form little piles of mud with spaces between them. The tub is set in and allowed to settle onto the tile all the way around. You don't need any water this way. Get the tub where you want it and leave it overnight. Caulk around the lip of the tub where it rests on the tile. Don't make a newbie mess of it. A very fine bead of caulk will do. ;)

Eric N.
01-06-2003, 10:51 PM
Sounds like a plan. This tub has 4 "feet". Each foot is a 4" square block of wood about an inch high. I'm thinking I'll make four piles of mortar for each foot to set in.

It is a Kohler Greek tub, 4 ft long and 23" deep, 32" wide. The early post made me wonder about the weight when filled. But I think I'm good. The tub occupies the site of the old tub. There are two floor joists under the tub, plus two joists that run parallel with the walls on each end of the tub.

John Bridge
01-07-2003, 07:14 AM
It doesn't hurt to make a few more piles between the feet. It's dead space anyway. I don't think you can have too much support. We do this for every tub, except the ones that have a solid base fiberglassed onto them. Those we shim.

01-07-2003, 07:47 AM
I set the tub in a pile of mud that will cover the entire bottom of the tub. Use a little body weight to squish it in. No soft spots.

Lots of experience with this. 1 tub, so far! :D

Eric N.
01-07-2003, 01:06 PM
I get the picture. Thanks for the lesson. I'll let you know how it goes.