[TomU]

I'm in the process of framing my basement bathroom and have a few questions:

In the rest of the house (less than 2 years old) it seems that they drywalled around the tub first, then installed the tub, then added water barrier and 1/4" cement board (overlapping the flange) and tiled over it. Is this the right way of doing it? I see a lot of pictures/instructions that say to install the tub right after framing, but then I'd have the drywall overlap the tub flange as well, wouldn't I? I'd think that the drywall behind the cement board makes the wall more durable.

Also, I'll most likely have a plumber do the rough in plumbing. Is it OK to frame it all and permanently anchor my framing before he comes do his work? Or should I not permanently anchor my walls quite yet?

 

[brockmiera]

I'm in the process of framing my basement bathroom and have a few questions:

In the rest of the house (less than 2 years old) it seems that they drywalled around the tub first, then installed the tub, then added water barrier and 1/4" cement board (overlapping the flange) and tiled over it. Is this the right way of doing it? I see a lot of pictures/instructions that say to install the tub right after framing, but then I'd have the drywall overlap the tub flange as well, wouldn't I? I'd think that the drywall behind the cement board makes the wall more durable.

Also, I'll most likely have a plumber do the rough in plumbing. Is it OK to frame it all and permanently anchor my framing before he comes do his work? Or should I not permanently anchor my walls quite yet?

Yes frame it all and he/she can run the plumbing where it needs to go. They will probably need to install some blocking to help brace the fixtures.

As far as the wall finish. I personally wouldn't use drywall anywhere in the shower/tub area. cement board alone would be fine plus some water proofing. A lot of people on here use redgaurd (or equal) or the kerdi membrane products. I am doing the same thing right now in my basement.

 

[TomU]

Yes frame it all and he/she can run the plumbing where it needs to go. They will probably need to install some blocking to help brace the fixtures.

That's what I thought, thanks.

As far as the wall finish. I personally wouldn't use drywall anywhere in the shower/tub area. cement board alone would be fine plus some water proofing. A lot of people on here use redgaurd (or equal) or the kerdi membrane products. I am doing the same thing right now in my basement.

I know cement board along is fine. But drywall behind waterproofing and cement board should be fine, too. Shouldn't it? I also think it would be sturdier, since the wall is only 2x4s. Only the wall where the drain/vent lines are going to be 2x6 due to lack of space.

 

[joecaption]

Drywall should never be used behind the tile board!!!.
The tub gets set 1/2" tile board, web tile tape gets set with thin set, wall gets water proofed with Red Guard, then tile gets set.

 

[TomU]

Drywall should never be used behind the tile board!!!.

Ok, what did they do in my house then? Did they use 1/2" cement board and another 1/4" on top of it underneath tiling? I can see that they used 1/4" cement board because there is a small spot where they forgot grouting. Actually, looking at it more closely it almost appears as if there is a joint between drywall and whatever is underneath the 1/4" cement board.

 

[brockmiera]

Just because things were done in other parts of your house one way doesn't mean its the right way to do things now. A lot of advances in technology have come along which in turn has made changes to building code.

I know for one that the main bathroom in my 1960's ranch has tile right over drywall. I also know that once I get ready to redo that bathroom I will have a bunch of mold to deal with.

There is no reason what so ever given everything that we now know to put drywall on consistently wet walls. If you want more support us a 1/2 or 5/8 cement board. I am not positive but I think that 1/4" is only for floor applications.

the absolute proper way was described in the post above.

I hope this has helped! Post some more pictures along the way

 

[TomU]

Just because things were done in other parts of your house one way doesn't mean its the right way to do things now. A lot of advances in technology have come along which in turn has made changes to building code.

I don't know if it matters much, but my house was built less than 2 years ago, so I assume it's done at least to code. I tried poking into the layer underneath the 1/4" cement board and it's hard as rock, so I suspect it's not drywall.

There is no reason what so ever given everything that we now know to put drywall on consistently wet walls. If you want more support us a 1/2 or 5/8 cement board. I am not positive but I think that 1/4" is only for floor applications.

Is there any reason not to use 1/2" cement board, water barrier and another 1/4" cement board on top? I like that the tiles are a bit off the wall, and would like to replicate that look in my basement bath. They're 18x18 tiles, in case it matters.

the absolute proper way was described in the post above.

I hope this has helped! Post some more pictures along the way

It has helped greatly. I just need to figure out what to do in order to frame the room the right size. Again, I'd love to replicate that look of the tiles being raised off of the regular drywall.

 

[brockmiera]

Well if it was built less than two years ago it seems like someone may have taken the easy way out and didn't want to cut drywall.

Nevertheless, other than being cost prohibitive I don't see any reason you couldn't do 1/2 and 1/4 on top of each other. Just make sure that you don't do any waterproofing until your final layer is on. Then tape/grout your joints and corners and waterproof with redgaurd or equal.

Once that is done you can start to tile.

Good luck!

 

[TomU]

Well if it was built less than two years ago it seems like someone may have taken the easy way out and didn't want to cut drywall.

Possible. I'm not 100% sure but it seems it may actually be concrete board underneath. I don't want to poke a hole on the other side, though. I do like the look of these tiles being raised off the surface a bit.

Nevertheless, other than being cost prohibitive I don't see any reason you couldn't do 1/2 and 1/4 on top of each other. Just make sure that you don't do any waterproofing until your final layer is on. Then tape/grout your joints and corners and waterproof with redgaurd or equal.

Luckily, cost is not much of an issue, material is inexpensive and labor is free (DIY) :wink:

If I use a membrande (like 4+mil plastic) between the two cement boards, would that work? I'm just a bit nervous about damaging the paint-on membrante when tiling over it, or how to make sure that joints/corners are absolutely water-proof.

 

[brockmiera]

No on the vapor barrier. That will be where water will accumulate first. Dont over think it. Concrete backer board. Tape your joints with appropriate joint compound. Cover screw heads. Let dry. Cover that with your roll on water proofer or use ditra underlayment. Tile right over it.

Sent from my SGH-T959V using DIY Chatroom

 

[joecaption]

The seams are covered with a web tape made for tile board set in thin set not joint compound as suggested, and the screw heads also gets sealed with thin set.
If you space that tile board as your suggesting you going to have a gap behind where the tile and the lip on the tub are. A great place for water to get into and mold up.
It's also going to through off the height of the edge or bull nosed tile goes.
Installing tile is not going to damage the water proofing unless your doing it wrong.

 

[TomU]

Thanks for all the suggestions. Here's my plan now:

Around the tub I'll install 1/2" cement board. Then I'm going to install the tub, add 1/4" cement board and have it overlap the flange by 1/2" and seal it with silicone. Then use web tape for all seams and corners, then "seal" all corners, joints, and all screw heads with thin-set. Then apply paint-on water barrier and then tile over it.

Does this sound right?

Only one question remains. The support studs where the tub is going to rest on: Should I install these directly to the frame, and have the 1/2" cement board go around it, or should I install them over the cement board with pressure treated support to the floor?

Thanks for all the help, I have a much better picture now :yes:

 

[Dean CRCNA]

If you install the 1/2" first ... will the hole in the tub be aligned with the drain? If not, then you may want to put tub in first and then 1/2" to allow for adjustment.

Paint on water barrier may take 2 to 3 heavy coats. Be sure to read the directions.

 

[oh'mike]

Why do you want to do this the hard way? Install the tub tight to the studs--then your 1/2 inch board to the top of the flange---How are you going to do the plumbing with the rock installed before the tub?

Most tubs have a fairly thick flange with a radiused roll to the tub deck----1/4" board will not get the tile out far enough to clear that----

You are making a mistake----------rethink that---Mike---

 

[TomU]

If you install the 1/2" first ... will the hole in the tub be aligned with the drain? If not, then you may want to put tub in first and then 1/2" to allow for adjustment.

I'll have to cut the concrete anyway because it isn't in the right spot anyway.

Paint on water barrier may take 2 to 3 heavy coats. Be sure to read the directions.

Will this fix the countless tiny cracks from handling the cement board?

Why do you want to do this the hard way? Install the tub tight to the studs--then your 1/2 inch board to the top of the flange---How are you going to do the plumbing with the rock installed before the tub?

I'll cut the cement board around the plumbing. Since it's below the tub anyway, it doesn't matter.

Most tubs have a fairly thick flange with a radiused roll to the tub deck----1/4" board will not get the tile out far enough to clear that----

I already have the tub in my basement, and it's the exact same tub as is used in my other bathroom. Since this is done that way upstairs I think it should work downstairs, too. The flange doesn't look too think to me.

You are making a mistake----------rethink that---Mike---

I hope not, but the room is already framed. Next step is to hire a plumber I guess.