# Bathroom Drywall Questions



## Big Dave (May 17, 2006)

You do not have to use green board. Green board is only water resistant and not waterproof. Yes if you can hang the sheets vertically and not have any seams then go for it. A good primer and paint will be your best defense against any drywall deterioration.

Dave.


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## DaveH (Jun 5, 2006)

Good word Dave. Green board is over-valued water VAPOR resistant junk. Good paint and lotsa caulk.

Two Dave's are better than one


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## AtlanticWBConst. (May 12, 2006)

Yes, MR - (aka Green Board) is overated. 

However, for a few Dollars more, I would still use it for it's water VAPOR resistance...(As we have for the past 20+ years of bathroom building and remodeling). 
As a practice, every knowledgable builder I converse with uses an MR board in bathrooms when not using Cement board...In fact every commercial and residential blueprint we get (we get about 10/ month) and review....stipulates the use of a 'moisture resistant' S/R or GWB in the bathrooms.

Can you use regular sheetrock in areas of the bathroom. Yes you can.

However, the new board being used is called "XP" - and you CAN get it in 10'-0" lengths, we just installed 10 footers, this week in one of our bath remodeling projects. It is also rated as 'mold-resistant'. Are all these things overkill? Yes. But isn't that the nature of the business ? (not to skimp especially when it comes to water and moisture protection?) ....especially from the 'building inspection & codes' standpoint.... 
Being on a budget is another issue.
I did some research, XP (made by National Gypsum) - Prices run about $5.00 per XP board over regular S/R. Average bathroom area uses = approx. 10 sheets = an extra expense of $50 (for an extra level of moisture and mold protection).


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## MrNoMaintenance (Jun 23, 2006)

I would run the 10’ boards horizontally as your eye will be less likely to see any taped joints --- from reflecting light --- on a horizontal run as opposed to a vertical joint.

I would have to agree with the two Daves in that paint and caulking are you best first line of defence against moisture penetration. Once the moisture gets through, it’s sort of “game over”, or can be. It would be a good idea to go with XP or cement board over MR. It’s all about No Maintenance down the road.


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## DaveH (Jun 5, 2006)

Mr. Atlantic...Now C-mon man! Your killing me here. Yes WE have used it for 20+ years an no there's nothing wrong with it. I do know however that just because it's in spec's doesn't make it right.(I have bid at least 6 jobs this year where an architect wanted green board used as exterior sheathing  ) Yes water VAPOR resistant. If your water vapor is getting to it then so is your water and it's gonna be a problem. Now XP board is a whole new ball game. Yes it is mold resistant. RESISTANT not PROOF. I'll bet if the water gets to it you'll have enough fungus growing on there to start your own mushroom farm. If XP board, green baord or any board has water of any kind getting to it you've got a problem. The studs it's nailed to are not mold resistant. The decking it's all sitting on is not resistant. All mold needs is a little dirt, sawdust, anything to start growing on. I have a condo project I landed in south Florida that consist of removing all the drywall on all exterior walls and replacing it with XP board. Why? The existing drywall is molding. They(the owners/architects think this wil solve the problem. I told them it won't and have made my concerns (in writing) known to them. The problem is the water getting to these areas in the first place. They have the cheapest windows, penetrations in stucco with no caulking on half of them, and horrible flashing. Nothing like putting a band-aid on a cut jugular vein..


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## Riddler (Jun 26, 2006)

Thanks guys. If my supplier happens to have XP board in 10' lengths, I'll opt for that. Glad to hear though that the difference between regular and MR board is marginal. In exchange for no seams, I am happy to spend extra time sealing and painting.


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