Can I adjust the slope?

[snowmobiledog]

I've been remodeling our master shower over the past month or so. I have already installed my pan, concrete board, curb, and waterproofing membrane (prova-mat) on the floor and walls. However, I did a quick water test to see how it all flowed and to my horror, found that there were spots where it didn't drain quickly... and in some spots almost pooling.

I took all the precautions (floor self leveler, pre-sloped foam pan...etc.). but I'm thinking I messed up 1/2 of the foam pan when thin-setting it into place. 1/2 of the foam pan (the part with the drain) turned out perfect... It's the second half that is not as great.

Not wanting to tear out the entire pan, I was curious if I could re-slope the small section with some deck mud or similar material? If this was over a cementitious material I wouldn’t ask, but since this re-sloping would take place over a sheet membrane, I’m not 100% confident it would take. Of course, whatever material I would use to re-slope I’d cover with another layer of sheet membrane to re-establish my waterproof pan.

I hope this makes sense? If anyone has any ideas, please let me know.

[Lazarus]

You may not need another membrane. If you can use a good modified morter to adjust it to about a 1/4" inch of "fall" from the farthest corner to the drain...you just might be good to go.

[cx]

Welcome, Chris.

I'm gonna disagree with Laz. It's the waterproof membrane on your shower floor that needs to be properly sloped, not just the tile installation. What he's suggesting will not accomplish that.

Your proposal to use some sort of cementitious patching compound (deck mud is not likely to work), covered with a waterproofing membrane might do what you need done.

I'd rather see you remove what you've got, create a properly sloped mortar bed, and cover that with a waterproof membrane. That would require a new drain, though, but it would be a far better solution, offering a proper slope with a level perimeter, which you will not have with your solution.

Would be a good opportunity to center you shower drain, too, yes?

My opinion; worth price charged.

[Davy]

Patching in a small area with thinset mortar will work but adding it over the whole floor and tapering it down thinner at the drain could be tough. Thinset is not an easy mortar to free hand.

[snowmobiledog]

Thanks, everyone. I appreciate your input.

I understand the viewpoint of a complete tear-out, but unfortunately with my DIY budget, I'm not able to do that right now.

Perhaps I should do a 24 hour flood test as-is, drain and then take pictures to get your feedback? I will also take a few pictures of my level bubble so you can tell me if I’m worrying about nothin (which I tend to do a lot).

[jadnashua]

If you think you can get the surface properly sloped with a cement based material, the safer solution for waterproofing would be to then add a new layer of the waterproofing membrane. Those pans have marginal slope and are not very forgiving if you don't embed them properly, or the floor wasn't perfectly level prior to installation. As long as you have at least a 2" overlap on any seam, it should stay waterproof.

[cx]

Originally Posted by Chris

I will also take a few pictures of my level bubble so you can tell me if I’m worrying about nothin...

Level bubble won't tell us anything at all about the flatness of your slope, Chris.

Deck mud is dirt cheap. DIY labor is free. You gotta buy more waterproofing membrane anyway. You'll have a much better product.

My opinion; worth price charged.

[Lazarus]

Yep, was just referring to small, "fix it" areas, as Davy suggested. Certainly not refloat the entire pan with thinset...

[John Bridge]

Hi Chris,

I'd like to see pictures of the amount of water that is not draining. People around here might throw stones at me, but you might just want to plan on wiping up a little water after each shower use. I recommend drying the entire shower with a towel anyway.