Shower pan installation error

[Infastocawn]

Hello, I recently installed a shower pan liner and the on top of it the pan mortar. However, once it dried, more than two weeks, I cane back to it and some of the area of the pan sounds hollow. The middle sounds solid, almost no sound, but to the sides and the edges, it sounds hollow. Is this normal? Do I have to take it up and reinstall it? Any help would be greatly appreciated.

[cx]

Welcome, Jose.

Difficult to say.

What did you put under your liner?

What did you use for the mud bed on top of the liner?

How thick is the mud bed on top of your liner?

How large is the shower floor?

[Infastocawn]

The shower floor is 3 by 5.

Under the liner there was concrete.

I used quikrete sand and mortar mix.

Thickness is about 3 inches to about 1.5 inches. I used a linear drain.

[cx]

You didn't make a pre-slope under your waterproof liner? Just laid it directly on the concrete subfloor?

[Infastocawn]

That’s right. No preslope.

[evan1968]

Congratulations, you get to try it again. This time, with a preslope.

[Kman]

Welcome to the forum, Jose.

Unfortunately, when the liner sits on a flat surface, it can't direct water that gets through the mud bed to the drain.

And if the drain flange where the liner attaches is sitting above the level of the floor, you would have a puddle of water until it's deep enough to spill into the drain. Eventually that water will stagnate and cause some odors you won't like.

So far, you're not too deep into this, especially since you're questioning your mud bed anyway. It would be best to take up that mud very carefully without damaging the liner underneath, and start over with a properly built shower.

There's plenty of information available in our liberry under the shower construction threads. I would recommend you spend a little time reading through the ones that apply to your situation. We'll be here to answer any questions you have along the way.

[ss3964spd]

Jose,

The problem is with the liner laying flat water is just going to collect on top of it instead of being directed to the weep holes in the drain body.

For a traditional liner system to work the first mud bed must be sloped to the drain, then the liner is installed on top of that sloped bed, and the second mud bed is installed on top of the liner. This way, any water that gets through the top mud bed will hit the liner and slowly drain towards the weep holes.

[Infastocawn]

Fun fact. When I started demolition of the bathroom I was able to see that the contractor had simply installed the tile on top of the concrete. There was no preslope or anything. Just the tile laying there. The bathroom never had any odor problems though. Anyway, I will demo again and restart the pan, hopefully this time I’ll do it right! Thanks for your input guys!