# Americast tub and Durock



## mtplus (Jun 22, 2006)

I installed an American Standard tub (Americast). The lip of the tub is about 1/4 inch. That means if I bring the Durock down over the lip of the tub, it will be 1/4 inch away from studs where it meets the lip of the tub. How can I make the Durock fit down over the lip? Can I notch the edge of the Durock?


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## Mike Finley (Apr 28, 2004)

Don't bring it over the lip of the tub.


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## mtplus (Jun 22, 2006)

*Americast and Durock*

Mike,

That is a good suggestion. I did not know that it was an option. I was going by the installation instructions on the manufacturer's website. Since I respect your opinion, I assume that nothing bad can happen in terms of water getting behind the Durock as long as the bather does not go scuba diving in this 'deep soaker' tub. Should I put as moisture barrier behind the Durock and lap it over the lip of the tub or just bring the ceramic tile down over the lip and caulk it?


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## Mike Finley (Apr 28, 2004)

I would switch to DensShield and then be able to skip the moisture barrier. We use a good silicone caulk to caulk the joint where the Dens and the tub meet. Bring the tile down to about 1/8 off the tub and caulk that joint with caulk color matched to your grout.

Traditionally the backer comes in front of the lip and I'm sure I will catch hell here for suggesting it otherwise, but I have seen lots of it both ways and I can't stand that bowed in look of the bottom of the tub tile.

We are have very low humidity so the tiny chance and the tiny amount of moisture that might find it's way behind the backer and run down the backer and not run into the tub but behind it really is no issue out here. In high humidity areas, I don't know if it would matter either. The moisture barrier over lapping the lip would certainly address that issue.


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## Double-A (Jul 3, 2006)

Mike's idea works well, but if you look closely at the spec sheet you might see they are using a shim between the rock and the studs to form a gap for the flange behind the rock.


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## Atricaudatus (Apr 11, 2005)

Mike Finley said:


> Traditionally the backer comes in front of the lip and I'm sure I will catch hell here for suggesting it otherwise, but I have seen lots of it both ways and ...
> The moisture barrier over lapping the lip would certainly address that issue.



I used your method Mike on my own bathroom, stopping the backer board on top of the lip and letting the tile come down over it. I used a 6 mil plastic VB behind hardibacker. It makes for a better look and hasn't leaked yet. I did a lot of reading over at John Bridge's tile-your-world forums before taking the project on, and that method is approved by the tileheads there.


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