Shower Project

[jadnashua]

There's a difference between waterproof and vaporproof...look at Goretex for example.

Stacking waterproof layers can have some bad end results.

There are a bunch of different backer boards. Cement based ones are NOT waterproof or vaporproof. The foam based ones are waterproof if the joints and penetrations are dealt with properly, but are not totally vaporproof.

So, it depends on what you're looking for, and how well you actually install it as to whether it will work for you in your circumstances.

FWIW, neither tile nor grout is considered waterproof, either, but is a decorative, wear surface. Even a good porcelain is not waterproof, but it must not absorb much to be considered porcelain, much less than 1% by weight.

[cx]

If you use a moisture barrier behind your wallboard, you would not be using any type of "waterproof" wallboard or waterproofing membrane on the inside of your wallboard. As to the moisture penetrating the wallboard, I would not be concerned with mold as a result as there would not likely be any food for mold in that space and the moisture that collected would gravity feed to the bottom of the wallboard and escape through leakage or evaporation. That's the theory, at least.

In your situation, real or hypothetical, you would not, of course, be using any moisture barrier behind your wallboard.

My opinion; worth price charged.

[eagle4x]

I know mastic should not be used in showers, but for the 1 row of 24x48 porcelain that I plan to install around my tub, is it ok to use mastic? The tub does not have a shower head on the wall but has a pull out shower head located in the base of one corner of the tub.

[cx]

Find one that indicates use with tiles that size and you could certainly do that, Mike. But when you go looking for that product, do bring a lunch.

[eagle4x]

@ CX, do you mean because it takes a long time for the mastic to dry behind such a large tile?

[eagle4x]

Some questions regarding my shower valve (pressure balanced), but 1st about the valve/connections:

1) Link to the valve: https://www.homedepot.com/p/Glacier-...9004/304685280

2) Connections to valve and shower head: 1/2" pex.

After looking at the link to the valve again, I noticed the flow rate is only 1.8 gpm. I read on a website that the best way to determine if a valve has a restrictor is to see how long it takes to fill up a 5 gallon bucket after removing the shower head. Also, the website said if a valve has a restrictor, that using a shower head with the restrictor removed will not increase the gpm. I assume from the website that a restrictor in a valve cannot be removed.

Other than the possible low flow rate from the valve my other concern is the quality because it's low end. I purchased it mainly because the style of the trim matches my tub and sink faucets and at the time I wasn't thinking about flow rate.

If the result of the 5 gallon bucket test indicates a much faster flow rate than 1.8 gpm, my 2 options are:

1) Do not replace the valve unless it fails. If so, the hole in the backer for the valve will be 6" and there's also an access panel in the rear that's accessible from the hallway closet.

2) Remove the valve anyway because it's low end and replace with a better quality valve but only if can find one where the existing handle/trim plate fits on it. The ratings of other Glacier Bay valves about the same as the existing one.

Have any of you had to replace Glacier Bay valves due to failure?

Which option you think is better?

If answer is #1, how hard is it to replace a valve with a 6" hole in backer and an access panel in the rear?

If answer is #2, and replies to this post is that it's difficult to replace a valve even with that much access, the time would be do it is now because backer not installed yet.

[Tile & Stone Guild]

Why is there ditra on the walls????

HD lower end valves guts will be more plastic than metal. Whether you care is up to you.

[eagle4x]

Jeff,
I installed the Ditra on the lower half of the studs and one small section above the valve because they are not plumb. After installing it, I pressed the backer against the Ditra and it did not flex.

How much more prone are valves with plastic guts more likely to fail vs. metal guts?

[jadnashua]

Most all mastics I've seen have a maximum tile size limit, and your tile exceeds all that I've seen. Doesn't mean one might not exist, but since you'll have some thinset around, why not just use that cement-based stuff...cheaper, and one less thing to buy?

[eagle4x]

Jim, the reason I was considering mastic for tile on tub surround is because it's pre-mixed and not a pain in the ass to mix like thinset.

[ss3964spd]

Mike, is the shower valve new? Or are you re-using the one that was already there? In the photo it appears it is supported only by the PEX lines.

Correct, if the valve itself is design limited to 1.8 GPM, a higher flowing shower head isn't going to result in more GPM. If the valve has a removeable restrictor it should be indicated in the installation instructions.

As far as replacement through the access panel, I suppose it depends on how large the access panel is and how much "play" there is in those PEX lines.

[Davy]

I would not use mastic in a wet area, use thinset. Go to Lowes or Home Depot and buy a mixer like this and put it in your cordless drill.
https://www.lowes.com/pd/QLT-by-Mars...rms/1000204941

[eagle4x]

Dan,
1) It's a new valve.

2) On the right side (1st pic), there's a piece of wood wedged between the pex and back of the hole of the 2x4, On the left side of the valve (2nd pic), there was a 2" long clamp nailed into the back of the stud holding the pex, but since your post,I removed the clamp and put a piece of wood like for the right side. There is no movement of the valve in either direction. The pieces of wood can easily be removed through the access panel.

If the valve ever needs replacing, it still may be difficult to replace it through the access panel because the left side of the valve further over than the right and the panel is located in a small closet. Therefore, I'll find out if it's possible to connect a valve like I did with my shower head in another bathroom...I moved it over because it was not in center of the shower. I connected one end of a braided stainless hose to incoming water line of shower to other end of fitting for shower head (see 3rd pic). If so, it would be easier to replace a valve using a pair of pliers than replacing pex pipe...comments anyone?

Another option would be to install another access panel so the left side of the pex is more easily accessible, but directly behind that portion of the shower wall is the toilet area and I'm not sure if I want an access panel there.
Also...
The last pic is a piece of GoBoard with a 6" hole cut in that I placed over the valve so I could take the pic. There is not enough clearance to replace pex pipe. It would take a hole 12" in diameter sufficient to do that, which is not possible because the trim plate not that large, So I don't understand how anyone could replace a valve regardless of type of piping unless either tile ripped out or if there's an access panel behind it. Therefore, wouldn't it be better to cut hole in backer/tile big enough only for valve vs having a 6" hole since I have an access panel?

Thanks for your comments...saved me a possible headache if the valve ever needs replacing

[Tile & Stone Guild]

Depends on how much the shower is used, I know money is a driving force. Personally I have the HD brand in a little used shower but spent the extra for the shower that is used at least couple times a day.

[eagle4x]

Jeff,
Thanks for mentioning the Ditra on the walls. Because of your post, I decided to remove most of it and sister 2 studs where they were out of plumb.