Bathroom Reno - Drywall or Aqua Board or Cement Board??

Question

Hello!

We are removing our corner shower and installing a soaker bath tub with a 4pc tub wall kit. When I removed the shower wall kit, I noticed that it was glued to drywall only!! I was surprised that it wasn't wet or moldy.

My question is - can I leave the drywall where it is and just install the aqua board or cement board over it, and then install the tub wall kit over that? Or do I have to remove the drywall?

Should I use aqua board or cement board? I am going to use a tub wall kit.

Husband says to remove the drywall....but I'm the one doing all the labor while he is away at work....so if I can leave the drywall on that's a plus!

Thanks!

Answer 1

Well, I think you have to knock it down and use a new one because of mold or it's too old and fragile. When i hired my plumbing contractor to install a new shower stall and delta shower faucet, he just ripped the entire wall and tiles right off and put up new ones (sorry if you don't want to hear this, maybe get your husband to chip in some of the hard work? This sounds like a job for at least two people).

Hope this helps (sorry if it's not the answer you want to hear =/)

Answer 2

Your husband is right. Get rid of the wallboard.

If you are not planning on putting up tiles there is no reason to use cement board.

I would get some Vantek board from Lowes, about 27.00 a sheet and use that. It's waterproof and comes with a 25 year warranty. It looks and acts like plywood. Really strong, just make sure you wear goggles when you cut it, the wood flakes and plays havoc on your eyes.

I used Vantec on a kitchen floor and also as a replacement for my patio roof. It rained twice before we got the shingles on and did no damage. And we get a bit of rain here in southern Missouri

Answer 3

I have run into this situation many times over the years, but in a lot of cases, the drywall is in really bad shape. Of course mold is always a concern but also the hardness of the drywall as well.

If you take the tip of a lead pencil and press it into the drywall in various points all over the area to be covered and the tip penetrates easily into the wall, that tells you that the board is soft which means there is water damage. If the drywall is firm in all areas, then most likely no water damage is present.

If you are successful with this little test and you do not observe any obvious signs of mold, then the reason is because, who ever installed the original shower did a good job of sealing around the shower.

With the type of install you are talking about now, if the wall board is sound, you should not have to tear it out. Of course this is optional, but you can save yourself a lot of work if you just leave it.

My question to you is this, and others will probably disagree with me, why install new cement board or aqua board at all, if the wall board is solid and if you seal the four piece unit correctly? These units when installed properly are not supposed to leak.  

My concern for you is that if you install cement board over the wall board and then install the shower surround over that, you need to make sure that there won't be a gap along the edges of the wall surround panels, which will reveal the cement board edging and possible cause the cement board to make the wall panels stick out from the wall.

If this is the case then you could end up having real water problems down the road and if you try to cover it over with caulk, it won't look good and might develop mold and leaks over time.

So if you are going to install the cement board mark out on the existing drywall the outline of the new shower surround and then cut out the drywall in that area and then you can install aqua (Green Board) or cement board of the same thickness in that area.

The best thing would be the recess the area you are going to cut out so that it come inside the outline you have drawn on the wall so that all patching stays  behind the wall panels instead of out on the wall that will be seen.

Please note, that once you open up the wall area you can block in with 2 x 4's to allow for solid nailing of the cement board.

Finally, before you begin this work, if you are going to leave the existing drywall, make sure you scrape of any of the old glue and smooth over the area with joint compound or other wall board patch material so the that the remaining visible wall area looks nice.

Every situation is different and there are many different ideas and thoughts that people will have and without actually seeing your job in person it is hard to make an exact judgment on how to proceed, but with all the years of experience I have had, I hope that you might find the solution to your problem with what I have written.

I hope this helps,  Rick

Answer 4

Hi, it's probably better to remove the old drywall but ,since you are going to cover it with an aqua board, it should be fine if you don't have mold on it. Its also a matter of the fit and the look. good luck & have fun.

Answer 5

Yes you can leave the drywall on and put the cement board right on top of it there should be no problem Good Luck