Drywall install question

[Richard]

Putting together a full bath in the basement. I've bought "mold resistant" drywall for the entire room.

It's going to have a stand up/walk in shower stall instead of a tub/shower. Shower is something like 4'x4' for general conversation.

My question is, the opening above the shower door enclosure (tramway?)

Anyway, should I go ahead and use this mold resistant drywall above the doorway or greenboard (moisture resistant) or is the mold resistant essentially BOTH mold AND moisture resistant?

I'm TRYING to get the wife to agree to tile above the door and the six inch walls to each side of door. It's a corner shower and door is placed on a 'cut off' corner. (instead of a square 4x4 box, the sides extending into the room are say, 3' and that hypotunuse is where the door is.

If she agrees to tile the door side of shower, then I can simply use durock. As it is, she wants to paint this wall and that will mean drywall, or something else if you have any ideas?

I just don't want to install the wrong thing above the door where all the steam WILL in fact, be exiting.

Any thoughts?

I won't be checking back until after 4:00 as my Bengals are on their way to open a can of whoop hiney in Pittsburgh!!

Here's to a good game for both.

 

[randy41]

if you are going to paint then any drywall will do as the paint will protect it from moisture. if you are going to tile you are right to use cement board.
the problem occurs when people tile over MR drywall thinking that any water seepage will not be a problem. But any kind of drywall that gets wet is history.

 

[RonMar]

Yes, if you paint and seal it well around the edges(caulk EVERY gap) then you should be fine. Most residential tub/showers that I have seen have regular drywall ceilings over the complete tub/shower area with the shower splash wall running all the way up the wall to meet them in the corners. Just paint it with a good, smooth, easy to clean oil based paint and seal all the edges well. In my experience(mostly colder climates), I have had more water damage elsewhere in the bathroom from condensation on cold surfaces from the shower water vapor. The toilet tank is good for this. You can also run into problems in the vent system that pumps the moist air outside. The pipe should be insulated to help prevent the moisture from condensing inside the pipe and leaking into the attic and wall areas. It should be sealed well or one piece to help prevent leaks and a vent timer should be used to keep the fan running a bit after the shower is over to help evaporate the condensed water.

 

[EddieWalker]

I like to use exterior paint in a bathroom. It's allot better than interior bathroom paint and I've never had a mold issue with it either. I had one bathroom that I used Kelley Moore paint with the mold inhibitor added to there bathroom paint that failed after a month. I bleeched the mold and scraped it and the paint off, then painted with Home Depot Behr exterior paint, and never had any mold again.

I don't think the brand matters very much, just as long as it's designed for outside use.

As for the sheetrock, I just use greenboard all over. It's more expensive than standard, but a bathroom isn't all that big and the overall cost isn't a big deal.

I've never heard of mold resistant sheetrock. Guess they came up with something new that I've missed over the years. How does it stop mold? After you paint it, does it still stop mold? Guess I don't understand how it works.

Eddie

 

[gsganzer]

Richard,
Your timing couldn't have been any better, for me to be able to take photo's of what i did for the exact same thing.

I've attached two photo's. To make a long story short, use the cement board all around your shower opening, whether it gets tiled or not. The cement board can get tape, bedded and textured just like the regular drywall.

On the first picture, the insides of the "light window" into the shower was done with cement board. Then it was tape, bedded and textured, so it matches the main walls. Also the very short parts of the "Hypotenuse" was also done with cement board and tape, bedded and textured. Anything that you think might remotely be in contact with water or has the potential to wick some moisture, I would do with the cement board. The inside of the threshold (hypotenuse) to the shower will also be cement board (but will get tiled, instead of textured) as will the shower itself. The shower I'm building is 6' x 6' and has two complete shower sets. The pan will be a one-piece cultured marble, custom pan. Look into a "pivot" style door, rather then a track door. Your local glass dealer can build a pivot door. I think they look cleaner because they have less hardware (no track etc.)

The second phot is of the same area, from a slightly steeper angle. To the far left of this photo, is the area where a drop in jacuzzi tub will go. The wall is cement board half way up (tile surrounding the tub) and then is moisture resistant board the rest of the way up. I had the tape,bed and texture lap slightly lower then the finished tile height. Once I fugure the actual tile height and snap a level chalk line, I'll take my DA sander and clean off the texture to that line to allow a secure backing for the tile.

Eddie,
The mold proof board is "paperless" and has a light coating of fiberglass on the suface (to keep the screws from popping) as well as some fine fiberglass strands throughout. I've been told that it will be replacing the greenboard. I used it throughout my master bath remodel. It's just like using regular drywall, only it's itchy after you've been working with it.

 

[tlbuser]

Your timing couldn't have been any better, for me to be able to take photo's of what i did.

The pan will be a one-piece cultured marble, custom pan. Look into a "pivot" style door, rather then a track door. Your local glass dealer can build a pivot door. I think they look cleaner because they have less hardware (no track etc.)

I just got the pan, walls and tub set for my project. Cultured marble pan and walls (48 x58) plus tub deck (72" air tub). I used green board. The way the pan is made, it gets fastened to the studs, then you apply drywall (or Durarock) from the pan lip to the ceiling, then the wall panels are set in place.After setting the pan to the framing, I needed 1/2" between the studs and the marble. None of the local suppliers had durarock in 1/2".

The subfloor under the pan needs to be completely leveled too. Did I mention that the marble pan is HEAVY!

 

[gsganzer]

The way the pan is made, it gets fastened to the studs, then you apply drywall (or Durarock) from the pan lip to the ceiling, then the wall panels are set in place.After setting the pan to the framing, I needed 1/2" between the studs and the marble. None of the local suppliers had durarock in 1/2".

The subfloor under the pan needs to be completely leveled too. Did I mention that the marble pan is HEAVY!

Tlbuser,
They just set my shower pan yesterday. I think they screwed up on the measurement and they made mine just a tad smaller then what they really wanted. In fact, I think It's going to cause me a few problems getting the cement board and tile to work out right. Mine doesn't have the cultured marble lip that runs up the wall. Instead the pan was poured inside of a rigid fiberglass cloth "basket" (cloth coated with resin so it's impervious to water). The fiberglass extends up the wall about 4 inches (like a nailing flange) and gets fastened to the studs. The cement board will stop at the top of the fiberglass. Then I take a trowel and float thinset into the recess between where the cement board stops and the pan itself. The tiles will bridge the gap between where the cement board stops and extend to the shower pan base, covering the thinset.

I'm probably going to have to shim one or two walls out a little with an extra sheet of 1/4" cement board on top of the 1/2" cement board I was planning to install. Anything less than 1/2" gap between the pan and the walls, would have been alright. But on one wall they're running just a little bit bigger then that size gap.

I'll take a photo tonight and edit this post, to make it clearer.

 

[Dargo]

When I built my pool house I used all greenboard but every experienced drywall installer told me that I wasted my money. First off, I used 5/8" not only for the ceiling, but all walls, all walls are 6" thick walls and filled with insulation. The reason they told me the sheetrock I bought was a waste is because they say that there isn't any water or mold resistant drywall mud, so they said I had a good idea but it won't work. The only way it will work according to three different drywall companies is to use the UGL drylock basement wall paint (or a similar brand) for the first coat over the walls and ceiling. They say that does lock out moisture and I can paint whatever color I want over that.

In the 'public' bathroom in the pool house I did that, and used a textured ceiling with the same material and a semi-textured wall with the same stuff; then painted the color coatings over that. So far, so good. It still ticks me off when guys somehow miss the urinal and hit the wall, but it does clean off and does not soak in any. Heck, I even bought one of those "target" urinal things to encourage a better aim!

 

[ToadHill]

My first job when I got out of College in the mid 60's was working at a drywall plant. The mold resistant drywall is made by injecting tar into the plaster before it is injected between the paper. It is both mold and moisture resistant.

 

[Michael_E_Tx]

Tlbuser, just messing around. Thought you might like to have this perspective corrected shot for your project record.