Drywall: Traditional, Greenboard, DensArmor Plus, Aqua Tough
We are going to get sheetrock ceiling lid on Wed. and insulated so we can start drying out walls – all of our heat seemed to be going up through vented soffits/ridge vent. We had been thinking of spending just a little more and doing greenboard throughout to do a step above drywall as they claim but then realized I really don’t know if greenboard, DensArmor, Aqua Tough is really any better than traditional sheetrock/drywall for mold. We have not ordered it quite yet. I did not know if green board meant they add something (like fungicide or biocide, which I am not sure is healthy) to tout more water resistant or why the claims that it could be better. Then, we had thought we might try DensArmor paperless fiberglass in bathroom but then our sheet rocker says he prefers Aqua Tough (which looks like cellulose and I am not sure cellulose is a better option). Okay, what do I know:) …hoping you all can help us out 🙂 We are climate zone 5/6 if that is important – N Idaho / Eastern Washington. 1) For all walls/ceiling (except bathroom): USG Mold Tough (aka their version of green board) or just stick with regular USG drywall? 2) For bathroom only: GP DensArmor Plus or USG’s Aqua Tough or just stick with regular USG drywall? (We will put Wedi board water proof system behind tile shower.)
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Replies
Greenboard has only one face that is mold resistant, it’s not the entire sheet that is different from regular drywall. I use green board in skylight wells as a little extra protection against problems caused by condensation, But I wouldn’t trust it as serious mold proofing if you have substantial moisture issues.
It sounds like you need to do some extensive air sealing. If your ceiling is open, you probably have access to things like top plates. Make sure to air seal everything while you have access!
Bill
I understand that, Bill - but what’s unique about the “facing” in greenboard to make it able to claim water resistance?
Does all greenboard, like USGs Mold Tough for example, contain fungicide/biocide - is that what is added/different to make it greenboard and water resistant?
Thanks, Bill!
I honestly don’t know the details, I’d look at a USG datasheet for that info. Green board is commonly used in areas that may see more moisture like bathrooms. I’ve used it in skylight wells because those areas are prone to condensation at times. Green board is a little more durable in these locations but only a little.
To add to the comment about using 5/8” drywall, it also helps with sound and preventing any sagging in the ceiling between joists. I built the ceilings in my own house this way for exactly that reason.
Bill
Oh, Bill, could you also explain to me what top plates are? And how to air seal them before drywall? (We have 2x6 walls with energy heal trusses.)
I did a real good job on slab on grade foundation and walls air sealing wise but couldn’t figure out air sealing ceiling well enough to explain to my husband unfortunately.
Top plates are the horizontal framing members that run across the top of the studs in a wall. A top plate is basically the top of the wall. There is a lot of info on here about air sealing this area. The basic idea is to seal holes used for wiring and plumbing, and any gaps. Canned spray foam is commonly used. I suggest reading some of the articles on attic air sealing which usually go into detail about this area of walls.
Bill
I do not think you need or want green board for your main ceiling, in your bathrooms Ok. Green board is less likely to disintegrate should it get wet ones or twice. The best way to avoid mold is to keep your house dry. Given enough moisture mold will find something somewhere to live.
You may want to choose 5/8 if your joists are 24 inches on center and you plan on more than R38 on top of the drywall.
Walta
Jamie,
I agree with Walter. If you care about mold prevention, there are several things you can do, but specifying special drywall isn't one of them. The keys to a mold-free house are (a) making sure that your interior relative humidity stays in a reasonable range, (b) never installing or using a humidifier, (c) using bathroom exhaust fans when taking a shower or bath, and (d) maintaining good housekeeping practices.
I installed Densglass in the bottom part of a basement wall where there were previous water problems. The water problems were fixed, my thinking was in case there is a very big rain storm storm and some water makes it past the waterproofing, the drywall won't come apart and the wall can be dried out. For areas that should not never see water, doubt it adds any benefit.
Extra drywall money is probably best spent on 5/8 drywall and some insulation between the bedroom/bedroom and bedroom/bathroom partitions.
If it were my house, I would prefer my drywall to not be moist resistant. You want to know as quickly as possible any moisture problem to fix it at the source. Even if your drywall was not damaged, any framing behind it could be and you don't want that to happen. Plus, a good paint is a much better protection against occasional water splashing your wall.