The Littlest Bathroom DIY Project

[DIYer]

Hello,
I've been visiting this site often as we've been planning our bathroom reno for some time. Just completed the tub surround demo and are glad we didn't wait any longer!!
The previous installation (only 2 1/2 yrs ago - previous owners) was tile board over green board. The green board was flush against the tub lip and, needless to say, was like a black mouldy sponge - in some places upwards of 3 ft from the edge. It was gross.
We are planning to replace the insulation (one wall is exterior), install proper vapour barrier (not that of consistency of produce bag), install CBU, tape & thinset joints, Redgard seams and window frame area, and finally - tile!
A quick question-
Our tub lip was not screwed or nailed to the studs - and I think the problem was escalated due to the fact that water just sat in that joint. There aren't any pilot holes, however. There is a bit of give in the tub and I was wondering if we could drill pilot holes (the tub is metal of some kind) and then one of us holds the lip up while the other nails or screws it. That way there would be enough of an angle to drain the water out. It's only a mini tub - does that make a difference?
Sorry for the rambling post - I kind of felt the need to vent a bit as well as seek advice!!
Many many thanks in advance for any info you could provide.
Cheers,
Corinne

[Davy]

Hi Corinne, the greenboard should have been left up off the tub a little but I doubt it wicked that far. The CBU isn't water proof and without a moisture barrier the moisture probably went right thru it into the greenboard. The joint against the tub is usually caulked. We normally don't drill holes into the tub.

[DIYer]

Hi Davy,
Thanks for getting back to me!!
I'm afraid I wasn't very clear in our situation.
The 'tile board' that was over the green board wasn't, in fact, tile. It was a sheet of some kind that had a 'tile' look to it. It was attached to the green board with construction adhesive.
I didn't mean I wanted to drill into the tub - it's just there's this bit that goes up (flange?) where the tub meets the studs and figured the tub should be attached by a nail or a screw or something...
Thanks again!
Corinne

[John Bridge]

Welcome Corinne.

Since the walls are open, you might be able to shove a shim or two under the tub to help stabalize it. I wouldn't advise drilling holes in the lip. It's there to keep water from going into the walls. If it seems to have a reverse pitch, welcome to the club. You are the proud owner of a cheap tub.

The only other point I can think of is applying RedGard to the seams of the backer board. If you are going to do that you need to cover the entire installation as backer board is not water repellent. Makes no sense to do the seams. All or nothing.

[DIYer]

Hi John,
What a super site you have here! I don't think we'd have the confidence to undertake this if not for you guys!!
I laughed out loud at your cheap tub comment!! This bathroom was completely re-done by the previous owners - and it most certainly was on the cheap!! However, it's our main bath - only 4x7 - and the tub is 3ft 10 inches long. We thought about replacing it but it's in pretty good shape and the wee tubs are hard to find.
So no to Redgard on the CBU seams? I thought I read that someone on here was doing that. If we have the vapour barrier behind - we're ok, right?
I still do think we should Redgard the window frame - we're going to CBU and tile that too.
Thanks again!
Corinne

[Davy]

Corinne, you must have a steel tub that has a thin, flat lip that goes right against the studs. I have never installed one but I have seen them nailed to the studs. Don't know if it's the right way to do it or not. Shim it till it's stable like John said, might try to get it level too.

[jadnashua]

From what I read, you can use something like a galvanized roofing nail (one that has a large head), and nail near enough to the edge so that the edge of the head holds the tub in place. It may not really be all that necessary, but wouldn't hurt. You could do it on multiple studs. You probably don't want to bend the tub doing this, as you may crack the finish and create rust.

[DIYer]

Thanks all!
Just realizing now how dumb it sounds to drill holes in your bathtub!!
I took another look and the lip really isn't all that big; I'd be worried about putting a hole to the studs close to where I just cleaned out all that disgusting mould!
Surprisingly, the tub is very close to level.
All of your advice is very much appreciated!
C.

[DIYer]

Hello,
At last we are finished the drywall and are installing the Easyboard in our tub surround (it really is easy!)
I know we use the special tape and thinset in the seams & corners but we can do that when we're ready to tile - right?
A caulking question...
The tub to cbu joint is pretty deep (1/2 inch cbu + thinset + tile) - should we caulk now just with the cbu up and then again once the tile is installed? Or should we wait and caulk all of it once the tile is in?
A floor question...
Can you thinset and screw the backerboard to the floor and then start tiling right away? Or does the thinset that adheres the board to the floor need to cure first?
Many thanks for your help,
Corinne

[LonnythePlumber]

I want to acknowledge the great plumbing advice that is provided by the responding posters on this site. I'm reading Corinne and getting nervous and then John B. says exactly what I would post. Shim, no nail and cheap tub. I almost would award him an honorary plumbing license. Then Davy identifies steel and shim. Followed by non-trade guy Jim with the galvanized roofing nail application we do use on the steel tubs.
I have no further comments beyond yours.

[DIYer]

Thanks Lonny.
We didn't nail the tub.
Do you know about the caulking or the thinset?

[LonnythePlumber]

I know that if I get caulking on my shirt it's hard to get out and that if you step in the tilers thinset they get P.O.'d .

[Davy]

Hi Connie,

you can tape the seams as you tile, this makes for a flatter job.

I would wait and caulk after tiling.

After installing the backerboard you can install the tile right away, no need waiting.

[DIYer]

HaHa!

Hubby is somewhat caulking challenged - last time it was smeared all over him and the walls (and some where it was supposed to go). We've often wondered if you could hire a pro just to come in and caulk (only half joking!).
Am a little (very) scared about mixing thinset but we bought the paddle today and when DH was checking out the pre-mixed stuff I didn't give in.

I did a fairly exhaustive search thoughout old posts and I think I have answered my own questions. If someone who knows what they're doing could just give me a yay or nay it would be greatly appreciated!

1. Tape and thinset all CBU seams in the tub surround (including corner joints) but do this just before you start tiling (to avoid lumps).

2. Put thinset and a few screws (but not in joists) on floor cbu and then you can start tiling right away.

3. Thoroughly caulk the CBU/tub seam with 100% sillicone.

4. Once tiles and grout are in place, caulk the tile/tub seam again with 100% sillicone.

Thanks again!
Corinne

ps - I don't know if you're allowed to plug a product but the CBU we installed was Easyboard and I must say it truly was easy. When we are drywalling I often shed a tear or ten (I hate drywalling!!!) but all we could say all day when we were installing the Easyboard was how easily it cut and how smoothly it went up. I wish you could use it on floors - I'm a bit scared of this Rhino stuff.

[cx]

1. I'd suggest you tape and bed the corner joints before tiling. The flat seams on the walls are the ones that give some people problems if they don't get them flat enough to begin with.

2. Put thinset and a lot of screws in the floor CBU. Use the manufacturer's fastener schedule.

3. That's what some folks say.

4. See #3.

Never seen any EasyBoard, but we've heard a lot about it here. I really don't know if the installation instructions are the same as those for CBUs. Best to check the manufacturer's instructions on the care and feeding of that, too.

My opinion; worth price charged.