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
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,
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.
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.
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.
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
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
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
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
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
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.
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?
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.
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.
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.
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.
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
Thanks loads for the advice!
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.
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.