Troubling choice in Land O Lakes FL Shower rebuild.

[Steve in Land O Lakes]

Master bathroom, 32" by 60" center drain. Cement slab floor.

The original shower had been built with sheetrock backer board, regular sheetrock. No waterproofing.

The rock not only didn't have any waterproofing the only seam that was taped was at the very top of the shower where the tiling ended.

Six by six wall tiles were used on the floor and the walls (slippery like all get out).

Curb built with three 2x4's covered with the pan liner, but the pan liner had nails at the top even on the inside (maybe 2.5" above the bed).

Hanging sliding doors with an overhead track supported on the side walls sitting on top of the curb.

Plain Jane shower head and a Moen mixing valve.

That was the shower to start with... It's a wonder there was no serious leaking long before now.

So When my wife said the floor is so slippery it is dangerous (6x6 high gloss wall tiles) and the grout is discolored in some spots; I said it 13 years old (we bought it three years ago), I will see about changing out the floor tiles and redoing the grout.

When I started to assess the DIY Job I took a close look at the drain and the tiling; the drain looked a little ill fit. It hadn't given us any problem as yet, but it wasn't right.

Along with the other possible issues the hot and cold lines (cpvc 1/2") come out from under the pan mortar bed to meet up with the mixing valve. As yet I haven't see where they are coming in from, but they are under the 2" thick mortar bed of the shower pan; exiting out from under the pan just in front of the side wall that houses the valve and shower head.

So if I want to install a new vinyl liner in the pan I have to remove the 2" thick mud which sits right above the two active water lines

Alternately on Redguard's Website and in a few videos they show the liquid membrane (two thick coats) being used as the waterproof liner of the shower pan. If I were to do this I could just grind down the top of the old mortar bed and brush on a bonding agent, then pour a New Top (1.5"at the walls & curb to just under an inch at the drain) onto the old mortar bed (not disturbing the old mortar with the two water pipes laying under it).

If careful with a solid cold steel chisel and a small sledge do you thick I can chip out the old bed without breaking the pipes (they are under the old liner , not embedded in the mud. They are under everything. From what I see where they exit the bed, the worker gouged out a small trough in the slab that they appear to be laying in (at this point I can only see an inch or so of the pipes).

This way I get to rip out the rest of the old damaged liner put in a new liner and pour a new mud deck.

Or would you leave the old mud base and top it off and then Redguard the whole area really well?

I don't mind doing the chisel work if that's the best way to go, but I sure don't want to damage those pipes. Especially if the Redguard would function well as a liner instead of the vinyl.

Though and suggestions are welcome.

Steve in Land O Lakes...

[jadnashua]

If you read through many of the posts, while a liquid applied membrane can work, it has to be done well and to exacting instructions. Personally, I'd redo the shower with a sheet membrane verses a liquid one. If you do that, you could even leave the drywall up. Only two sheet membranes that I'm aware of have been tested and have the certifications for use over drywall in a shower: Kerdi and Hydroban sheet membranes. Others are certified for use over cement board, which could be used for any of them, but drywall is cheaper, easier to cut and install, and generally, readily available in larger sheets. The screws are cheaper, too. There are advantages of having a completely waterproof shower right underneath the tile.

Embedding the supply pipes in the mortar bed is risky...it also would mean you'd be wasting more of your hot water trying to heat the surrounding cement.

If your existing setting bed is properly sloped and intact, you could reuse it.

FWIW, you don't really 'pour' a shower pan...you pack it. When using the preferred stuff, it's more of like working with wet beach sand, not a more viscous cement product.

[Davy]

If I understand you correctly, you're asking about removing the tiles off the mud bed but leaving the mud and painting Redgard over it as a new pan. You can't do that because there's no way to seal it off at the drain. Painting Regard up to the grate won't seal off and water will leak thru.

I've used the paint on membranes on curbless showers because with that design there's one less med bed, so it can be made thinner and lower. They seem to work when installed correctly but I still would rather have a PVC pan liner. They are very tough but just like everything else, they have to be installed correctly. The biggest problem we have these days is improper installations, like your shower with nails thru the liner. Most are installed incorrectly. But, many installers like the surface sheet membranes like Kerdi and those work fine too. Again, as long as they are installed correctly.

From what you've explained, I'd want to yank it all out and start over. To start with I'd want to take a close look at those plastic water lines that are under the mud and see if they can be run thru the walls.

[nelsonkoehn]

Am I not understanding? The liner is punctures already. It needs to be replaced.

Are you asking if you can re-use the existing base that is under the existing liner?

There is a slim chance that can be used. Plan to redo it.

Is your house plumbed with cpvc in the slab?

If not, it's time to redo that plumbing for the shower.

[Steve in Land O Lakes]

Florida, concrete slab floor.

Original liner is damaged and partially removed.

CPVC is the pipe material the water lines are made of.

The water lines aren't embedded in the original mud, they run under the liner across it; laying in what appears to be a partially hollowed out trough.

The sheetrock is already gone, down to bare studs, all of which look fine; walls are even pretty flat.

The top of the round drain is embedded in the mud bed can't be moved and has a small gap at the top of the drain barrel. the grid and drain barrel appear to be glued directly onto the vertical drain pipe protruding from the floor.

The after taking up the floor tiles I am left with the mud bed of the original shower pan with the residue of the thin set that was used sitting all over the top.

The curb is dismantled.

I want to install the Wonder Board Light that Home Depot has locally.

Question- should I leave the mud bed intact and just clean off the thinset from the top (and then pack a fresh top over that using sand topping mix, and a bonding agent)?

I realize if I do that I have to chip out at least 1/2" around the drain to allow for enough mix to cure strong; and leave room for the New Tile and Thinset to meet the top of the drain properly.

This option doesn't give me a vinyl liner, but it also doesn't disturb the water lines running under the original install. I would then Redguard the whole inside of the shower, double coating the bottom pan area.

Or Do I attempt to hand chisel out the original mud bed trying not to break a water line; pull up all the old mud bed, remove the last of the old vinyl liner and install a new three part drain with a new liner?

I am not worried about the extra work I guess I just want to know if not having that new vinyl liner (using Redguard instead) would be a deal breaker for you?

If you think the carefully applied Redguard would work as well as the vinyl for the shower pan it certainly would be easier than hand chiseling out the old bed and starting from scratch.

But I would chisel out the old and start from the slab if you think that is the best way to go; I want to sleep without dreaming about a flood in the house

Again, thank you for your advice and thoughts, they are much appreciated.

[nelsonkoehn]

You may have to give us some pics.

Does this mud bed have a slope in it? And does it set high enough that with a surface membrane it will drain?

I don't know of a drain that, used with a liner system, that you can replace the liner with a surface membrane, and the drain can be used.

It sounds like you may need to replace the drain assembly also.

But, pics, please.

[073Manager]

Using a red guard in combination with the liner will create a mold sandwich underneath of your shower floor. Your only option would be to replace the entire shower pan and run liner 6" up your shower walls. If you use red guard, the entire surface of all of the CBU and shower pan MUST be coated. if not, you can run into a problem where moisture wicks behind the red guard and into your "mold sandwich". I don't like telling people this; but, my recommendation would be to replace the shower or use a foam pan like wedi to ensure that you are not compromising anything.

[Steve in Land O Lakes]

here is the current state of the shower...

[073Manager]

Steve,

It appears as if the liner does not go up 6" on the walls. If using red guard on your shower floor, you need to use a divot method so that your weep holes of your drain can still drain water. You have already done 90% of the demo. The extra 10% can save you a lot of headaches and money in the future.

[nelsonkoehn]

The liner needs to come out. Looks like a very slim chance it has a proper preslope underneath for the liner to drain. I also don't think you need to worry about those lines being embedded in concrete. Pull the liner out and then we'll see what needs to be done with plumbing.

[073Manager]

https://www.youtube.com/watch?v=Zc70Glmtw18

Here is a good video on usage of the divot method

[Steve in Land O Lakes]

After reading the welcomed advice from you all I believe the best thing to do is carefully get the mud bed & the last piece of the old liner removed. Hammer and chisel time! I will start from the bare concrete slab. I will get back with pics in a few days. Wife said said no Demolition on Easter.
Thanks again for the input.

[073Manager]

Steve, you are making the right decision. Good luck to you and post pictures for us. Please reach out if you need any help!

[Davy]

Give the mud a few good licks with a sledge hammer and it'll come right out. Most folks are surprised how easy it will bust up. You could have it out long before you have to hide eggs.

My grand son ready to color the eggs.

[Steve in Land O Lakes]

It took a hour or so of hammer swinging; including getting the debris into 5 gallon buckets for garbage day, to clear out the old mortar bed.

The floor of the shower is now down to a reasonably clean slab floor.

BTW my concern over the water lines running under the slab were unfounded. The parts of the 90 degree fittings I saw before removing the mortar made it appear they were sending the lines under the slab. They were not. They only redirected the lines an inch or so before they went straight down under the foundation. Worried for a day and a half over nothing...

There was no moisture anywhere under the mortar. Doesn't seem possible given the departure from best practices in the construction above it? I hope my redo is as dry.

The exterior wall has some brown paper insulation and some green strips of 1x2 instead of studs attached to the exterior block.

The plumping is dry, just the small arm for the shower head and the cartridge & "Guts" of the Moen mixing valve.

One electric line running through on the long wall.

The bottom drain flange flush with the foundation slab, the top flange clamp on top and then the drain barrel protruding. The was some gooey yellowish mess smeared around and under the top flange and the surrounding area just outside of the bottom flange (no idea what it is).

Pictures attached.

Need some advice on the sequence moving forward:

1- Do I need to add 2x4 blocking between the bottoms of the studs?

2- Should I be building the curb now ( I am planning on making out of three 2x4's, as the old one was)? I am figuring I have to have the curb built in order to pack in a pre-slope, yes?

3-Should I try and get the old drain disassembled or cut off completely now?

4- Is it time for me to remove adjacent moulding from around a door (On the wall the plumbing is on) and clean out remnants of the old sheetrock?

5- Try to get a straight edge of sheetrock at the top of the shower where the jagged and broken pieces of the existing rock remain (after I removed the rock from the shower)...

6- Wife would like a Niche or two. Would buying the ready made ones ensure a better outcome or can a build it yourself frame out work as well? Further would you consider a 32" niche on the long wall (with a cutout of the middle stud); or would you favor two 16" niches between studs (so there is no cutout needed)?

Just need to know what you would do next. Thanks in advance.