Shower Pan Reline

[Joe S]

The situation is that my shower was hot-mop and mud job with tile made

20 years ago. I've taken out all the tile and mud and metal lath and removed all the loose tar paper from the sides. The floor is still intact so far.

The question is...what's the best path from here? Do I need to remove the tar on the floor down to subfloor? Or can I just take off the drain and install a liner over the tar with some felt in between to protect the liner?

I guess I could also get a guy in to re-mop it, but that seems like more trouble and expense.

Open to advice, and thanking you in advance,

Joe

[G Henslee]

If you install a new liner there's no need for that tar to be there. I would go down to the subfloor if I were you. Cleaner job imho. This way you can pre-slope the floor prior to the liner. The drain assembly should be a two piece EZ test which allows you to sandwich the liner between the pieces. If you are not familiar with installing one of the vinyl liners here is a good site with pictures.

[Joe S]

protect

assembly

Yes, thanks. That pictorial is the first one I ever saw.

My thought about the tar is that leaving it there is (obviously) simpler and I'm probably not going to be able to get all the black stuff off anyway, so lining over it, if it wouldn't cause any problem, would just save time and effort. Of course, if it's *better* for it to be scraped down, then I'm more than willing to do that.

Joe

[G Henslee]

Is it just a simple layer of tar, or is there tar paper there as well, making it 'built-up'?

[Joe S]

there.

problem,

I have not dug into the floor, but the sides had tar paper and also some fiber mesh at the corners. It doesn't appear that it was built up so as to provide any appreciable slope, if that's what you mean, but there could be paper embedded. Not sure.

Joe

[G Henslee]

There's most likely paper embedded. I would pull it all and start clean. It will allow you an oppurtunity to properly inspect the subfloor at that point as well.

[Joe S]

Sounds like a plan. I just didn't want to do start something that I would later regret.

Also, I've seen another installation plan where the fellow lays a sloping layer of mud (thinner than the main layer) then felt then liner then the thick mud bed. The theory being to give the liner a slope to enhance the drainage.

What's your opinion on that method vs. the one in the link you provided? I don't mind going to that trouble if it's going to be somehow better.

Joe

[Joe S]

Please ignore that last question. The one you listed of course does the pre-slope. Sorry.

Joe

[RicodJour]

I personally like to have the pan sloped. Can't hurt, might help. If you're going to go the lath/mortar route be very careful with the lath. It has very sharp edges and you probably wouldn't notice the pin prick that causes you major headaches down the road.

There are other products that are liquid-applied waterproofing and are put on like paint with tape over the joints and corners. They ain't cheap, and not necessarily that much less work to install, but they put the waterproofing directly under the tile - the tile is set right on the membrane. Check out Laticrete's web site for installation instructions. You'd probably be using 9235.

R

[G Henslee]

No problem. fyi - I don't use any mesh when I pre-slope. Possibility of puncturing the liner.

[Joe S]

Possibility

I don't really understand the danger of the mesh getting near the liner, except on the curb. Are you talking about mesh potentially poking up through the pre-slope sometime in the future after some house shifting?

So, you prefer to go subfloor, roofing felt, pre-slope deck mud, liner, deck mud, thinset, tile.

Speaking of the curb, any danger of the curb lath damaging the liner up there, already allowing that we do not staple the lath on the inside of the curb?

Joe

[G Henslee]

No real danger, but a possibility and not necessary. I don't use lath or wire in either the pre-slope or the deck mud, and your sequence is correct.

As for the curb, the vinyl liner is pretty tough - 40 mil. If you're careful the lath should pose no problem. When cutting it try not leave sharp corners.

I also don't use admix liquid for the mud.

Plaster or mason's sand, portland cement, and water for deckmud. For walls, lime is added.

[Joe S]

I took up the tar layer and found underneath about 4 or 5 layers of asphalt shingles. Is this a standard thing to have done? It seems kind of cheezy, but it came up pretty cleanly, so it did okay.

Now, I'm left to deal with the drain which is ABS. I've taken the top flange off and am now wondering what exactly to do. I imagine I could re-use the bottom part of the drain rather than cut it out and replace the whole thing. Is there any reason I wouldn't want to just get a new top that mates with the existing bottom?

[G Henslee]

In my area of the country I haven't seen that in older showers. The hot moppers here don't use it. They use 30 lb. roofing felt/paper. Some times a roofer is used for this task, so it's not surprising there'd be that material there.

Aren't you glad you removed it all now? ;o) How does the subfloor look?

You may have to buy the whole thing to get the top half. But by comparison to replacing the entire fitting, it's cheap. Yes, you can just use a new top. Cast iron EZ Test drain.

[G Henslee]

Oops. I figured you had CI. While I have used a few plastic ones, I've mix-n matched the pieces with CI. What's wrong with the top piece of the old one?

I'd stick with the plastic if that's what's there now and take the old piece with you when you go shopping for comparison.

[Joe S]

felt/paper.

Well, there's nothing "wrong" with the old one except that it's...well...old. And it's got tar on it. And it's....old!

I could clean it up and re-use it and save a couple of bucks.

I am also slightly relocating the drain. It's currently not exactly in the center of the shower (off by a couple of inches in one direction) and we're putting in a Boyce & Bean beach glass rosetta

with the drain in the middle (of course), so I'm thinking it's worth the trouble of getting under the house and doing the work. Hell, might as well...it's just some danged ABS and plywood.

Joe

[G Henslee]

That's the spirit.

[Joe S]

I was at the store and looked at the drains and saw a 3-piece plastic Oatey with threaded drain "throat". Is this threaded so as to be adjustable? If so, I am assuming that it stays put and doesn't want to turn once your deck mud has solidified? I noted that the threads on the female side are not continuous...that is, there are 4 vertical voids so that water can easily weep/drain down the threads.

Joe

[G Henslee]

It's adjustable, yet won't move with the deck mud around it. You're correct about the slots being for weepage.

[Joe S]

Sure. It took about a 30-45 minutes and worked off 1/3 of that piece of pie I had for dessert, and generated a can of nasty trash that will go into the landfill, but sure, it's good to get down to the clean, dry subfloor. I can admit that much!

Just for clarification, you are suggesting to mate a cast iron top onto the existing ABS flange, right? Not that I think there's anything wrong with that, but I just want to make sure, since the top I'm taking off is plastic. Is there a benefit to using CI?

I will assume that when I get to Lowe's I'll find a few different sizes of drains, but once I find the right size, they'll all have 3 bolts of a standard size?

Thanks loads for the advice!