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Lmudave
06-10-2019, 05:50 PM
New to this shower building business, man it is a lot of research and work. I am building a traditional shower pan of mud, vinyl liner, mud. I had an issue where my drain was just slightly higher than I wanted after the final mud bed dried. I used some Mapei planipatch to try and fix the pitch of the floor and bring it up to the level of the drain by just about 1/8th of an inch. I realized that this might cause a problem though.
Does anyone here know if planipatch is porous. It seems like this could keep the water from seeping through to the liner and down the weep holes. Any help would be greatly appreciated.

Thanks!

Dave

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Lou_MA
06-10-2019, 06:33 PM
It’s not a waterproofing material so I’d think it would still let moisture through, although probably not as quickly as deck mud. I wouldn’t be surprised if grout joints on the shower floor stayed wet for longer.

cx
06-10-2019, 07:16 PM
Welcome, Dave. :)

Hate to ask the obvious, but why would you not simply screw your top drain section down a little more to accommodate your tiles?

Lmudave
06-10-2019, 07:33 PM
Good question, I was not very specific regarding my setup. I have a linear drain set into the top mud bed, it was about 1/8” higher than I wanted and like a true genius I put down planipatch without fully thinking it over. I guess I’ll test and see how water permeable it is, but I think I will likely have to either scrape it all off if possible or take out the whole top mud bed. Ughhhh

CaliGrown
06-10-2019, 08:38 PM
Not an ideal situation, patching material is much denser than deck mud, and even though it can be thirsty, deck mud is a superior substrate for your shower floor.
What size tiles are you planning with your line drain?
Patchers are hard to scrape up once they’ve dried up, might have to redo the whole bed like you’re thinking, or possibly take a cup wheel to surface grind the patcher off. Either way, I see a mess in your near feature.

MAPEI - Technical Service
06-11-2019, 07:05 AM
Hey Dave,

I don't usually like to strike fear into folks, but Planipatch has no business being in a shower, I'd get every bit of that stuff chipped out of there, and back to solid deck mud before proceeding. Once you're sans-Planipatch, shoot us a couple photos of what you're looking at so we can help you move forward in the best way.

Welcome to the forum!

Lou_MA
06-11-2019, 11:38 AM
Holden - I’m curious why you say it has no business in a shower?

What if the slope was being fixed prior to a topical membrane? Since it would be underneath the waterproofing, would it be ok then?

MAPEI - Technical Service
06-11-2019, 01:07 PM
Holden - I’m curious why you say it has no business in a shower?

What if the slope was being fixed prior to a topical membrane? Since it would be underneath the waterproofing, would it be ok then?

I don't want to open up a can of worms here, but Planipatch is a moisture sensitive product, so it being wet constantly is not good for the integrity of the product.

Under a topical membrane is kind of a gray area, and you'll get a slightly different answer depending on who you ask, but the long and short of it is that if the patch is protected from excess moisture, it should be fine. If there is a pinhole in that membrane, moisture migrating up from the slab, or something else going on that may keep the patch wet, it will not fair well.

If you were to call me and ask what to use to fix the slope in a mortar bed before applying a membrane, I'd tell you Quickpatch.