# primer for humid bathroom? tile over top?



## George Z (Mar 15, 2005)

That primer will be fine.
Very sticky to work with and sold by the devil, but it will do.


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## ProWallGuy (Dec 12, 2003)

George Z said:


> Very sticky to work with and sold by the devil, but it will do.


:laughing: :laughing: :laughing:


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## MacDoe (Nov 18, 2006)

O.K not sure what that means, who is the devil?


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## George Z (Mar 15, 2005)

The "devil" is a metaphor for the retailer you bought the paint from.
To most of us, they are the competition and one of their purposes seems to be, to put us out of business.
Most professional painters that pass by here don't like using BEHR Paints.
Having said all that, what you have will work fine for your purpose.


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## Bud Cline (Mar 12, 2006)

Where are these walls to be tiled? You should know that paint is a known bondbreaker for some tile installations. Are these walls ina wet area such as a tub surround or what?


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## MacDoe (Nov 18, 2006)

*Tile over primer wall or just tile?*

Thank You for explaining, and for your reply to my post. Yes I plan to tile the entire tub surround and carry the tile half way up the wall behind the toilet and then the same for behind the sink. I have spent quite a bit more money than I originally anticipated on the tile thanks to the better (took her 5 months to decide on tile) half. I was only planning to prime the areas that have drywall mud compound where the tile will go and then prime and paint all other areas. I bought the primer only, as the selection on paint color by my calculation should be 5 years from now, all things considered there are many more shades of paint than different tile in our area. I want to make sure to do this properly as this is the first time I have done drywall or tile laying. I think I am into the fun part of this project as I have overcome the re-wire and replumbing portion, but as I have already learned from this not to be to confident,but, I wanted to first consult the experts. So should I prime before tile or just lay tile over top of drywall/mud bare as to not "break the bond" ?
Sorry for going with Behr, the Devil made me do it, do painters not like Behr for where it is sold or is there a quality issue? Thank You


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## Bud Cline (Mar 12, 2006)

There may be a little confusion lurking just around the corner here.

In the dry areas primer would be OK but you can use mastic tile adhesive in those areas and you could just as easily skim-coat the drywall mud with the mastic before installing the tile. If you want to prime these areas that should be OK also as this is done all the time.

In the area of the tub surround this may be a different story. If there is a shower with this tub then the drywall shouldn't be there at all and nothing you do to prime the drywall mud will last for very long. This is with one exception. That exception would be to use a liquid waterproofing such as Redgard (sold at Home Depot) to waterproof the drywall mud. The thing is....this isn't the answer either and the drywall should be replaced with a suitable cement board tile backer.

So.....shower, or no shower?


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## billinak (Mar 16, 2005)

I'm suprised no one else has mentioned that you CANNOT put tile on drywall, no matter which primer you use. You must first demo all the drywall and replace with cement backerboard, otherwise you're looking at a very temporary tile job that will just cost you money to replace when it all falls down around your ankles in another year or two.


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## dougrus (Sep 16, 2006)

billinak said:


> I'm suprised no one else has mentioned that you CANNOT put tile on drywall, no matter which primer you use. You must first demo all the drywall and replace with cement backerboard, otherwise you're looking at a very temporary tile job that will just cost you money to replace when it all falls down around your ankles in another year or two.


Not to be confrontational, but this is not true. You CAN put tile on drywall surfaces. In a wet area that gets direct exposure to water it is definetly a no no, but if it is a backsplash or other wall tile applications it is perfectly fine. Drywall that is painted is not a good surface because of the bonding issue. Of course its not quite as good as cementboard, but its done all the time.
Tubs and shower surrounds of course you must do CBU


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## MacDoe (Nov 18, 2006)

hi there I have cement backer board for the tub surround and water proof drywall for behind the sink and toilet where i will be tiling from the floor to about half the wall behind the toilet and sink. the tub surround am tiling all the way to roof but not tiling ceiling. So should I only primer where I am going to paint?


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## Bud Cline (Mar 12, 2006)

MacDoe I'm not a painter but in this case I will say "yes" to your question: "primer only where you are going to paint."

The raw drywall would be better for the tile adhesion.:thumbsup:

I will also clear up another point. You don't have "waterproof" drywall, you may have (MR) moisture resistant drywall. For future reference, even MR is not to be used in a wet area.:no:


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## Bud Cline (Mar 12, 2006)

I also meant to ask earlier: "Why is this bathroom humid?" Are you saying this simply because it is a bathroom?


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## joewho (Nov 1, 2006)

Waterproof drywall...meaning "greenboard"?

I have to say, I did a job once where I ran the primer onto some greenboard and the tile installer wouldn't hang the tile on it.

I had to go back with a wallpaper perferator so his adhesive would soak into the drywall.

I'm not a tiler, but in construction I see them hang tile directly on to greenboard all the time. They prefer that over a primed surface.

Your configuration should be fine.


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## MacDoe (Nov 18, 2006)

Thank you all again for your responses, and thank you to my better half for barging in on this post. I just got home from work and began to read the responses from MY last post #4. Then I got to post #11 , low and behold it had me MacDoe next to it. Guys, that is my girl at post # 11. She must have been checking the responses while I was at work and decided to clarify that I did not use just ordinary drywall in the bath/ shower surround. She did confuse things a bit , bless her little heart though she likes to be involved, maybe felt she should defend my efforts as soon as possible, I really don't know why she did this, she could be involved more by picking a paint color already. She saw my other post obviously and I got raked for making jokes at her expense, not really though, she laughed at herself as well. She's cool, anyways, I would like to clear this up as it is being beat to death. I did not use cement board in the tub surround, but rather a product called dens-sheild , it extends about a foot past the tub skirt then to the ceiling. I had a piece about 3' by 5' left over so I used it for the ceiling directly above the tub. I thought this would be added moisture protection from steam of a shower to have this on the ceiling but now that I am thinking, the surface of this dens sheild is very rough probably to grab the tile adhesive and I will have to think of a way to smooth this out. Does drywall mud absorb moisture? I put drywall mud all over the seams of this dens sheild in the tub surround as well as tying it into the green board outside the tub surround. I guess what I am asking for is an answer to this question: should I prime the drywall mud so that it will seal out moisture that may get behind the tile or did I go wrong by using drywall mud in the first place for this dens sheild. Maybe I should have used this red guard the home depot sells to smooth out the seams or maybe I should have used nothing at all but rather use the tile adhesive to fill the seams, I don't know, the more I think about this the more I think that I should not have used drywall mud in the tub surround. I spoke of the humid bathroom because bathrooms are humid right ,you nailed it.


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## joewho (Nov 1, 2006)

You shouldn't have mudded. I would remove it. Use tile adhesive in the joints. Did you tape the joints? That would make it easier to remove. 

Dens-shield is approved for wet areas where greenboard isn't. You can safely tile the ceiling too. Smoothing it will probably be a waste of time. Either replace it with a paintable surface, paint it the way it is, or tile it. Tile will give you the most bang for the buck and you won't have to do extra work, which is what you tried to avoid by buying dens-shield instead of cement board.


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## Bonus (Aug 25, 2005)

I've installed dens-shield before and have painted it with no problems, customer was happy.


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## Bud Cline (Mar 12, 2006)

If you'll wet the drywall mud that was used on the Denshield it will easily scrape off which is what must be done. A wet spnge can then be used to clean off any remaining residue. Then the joints can be filled covered with alkali resistant seam tape and filled with thinset mortar.

Any Denshield/drywall joint that may exist well beyond the tile termination can be finished as you have done already with drywall compound if you are going to paint it.

I would also suggest tiling the ceiling at this point. This way you won't have to deal with the texture of the Denshield.


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## MacDoe (Nov 18, 2006)

Holy expletive word that starts with an f ....tile guy, am I glad I checked in here. So that was a fairly stupid idea to mud this area or what? Why, exactly is the mud no good? Does it hold water and then slowly rot denshield board or worse yet mold? I just need to know? I did tape joints, not that it matters anymore. I thought tiling the ceiling would be so cool, but I don't have any idea how to hold the tiles up there until the tile adhesive dries. I was planning on using a product called omni grip for the wall tile and I purchased a bag of versa bond fortified thin set mortar for the floor. Originally was told that I could use omni grip for both the wall and floor but on a return visit to the same store a different guy told me that omnigrip on the floor is a no-no among pro tile guys. What do you say? I have a very large pail of omnigrip now and that shtuff is expensive, I think eighty dollars, not opened yet. either one. What does 2 set mean? it says that on packaging of both these products? What is alkali tape? I think I used a fiberglass mesh tape flexible and sticky but I could be wrong on this but will find more specifics on that when I can. Thank you so much for all this info guys I really appreciate this help. One day soon I will get a camera and send pics. I will definately tile the ceiling when I find out how. The tile will flow right out the tub area but drop down to half the wall about six inches outside the tub as that is where the densheild line ends and the green board begins so that would probably not fit your description of "well beyond the tile termination point" will it. This detail I cannot fix, I am not ripping that out and not buying more dens sheild, but would like to find the best possible compromise for this dens sheild to green board merger, someone suggested a skin coat of something earlier. I will remove the mud from the tub surround area though for sure, (i hope it comes off). What is this red guard stuff all about? Would that stuff help me at all? Thinset would not seal the mud would it? not second guessing but I did not want to make a mess of the dens sheild coating by sanding paper it off. Someone should make water proof drywall mud clearly marked or tell the guys at home depot not to recomend the method I used. what a pain, I can now relate to the devil analogy of these guys but I guess i should share the blame somewhat because I did not listen to my gutt feeling until after I applied it. I figured a large store like this would have well trained people to offer solutions so I took their word. I should have signed in here earlier. I think there is no experience that compares with actually getting your hands dirty with some of these fine arts not to mention the importance our forefathers of the trades that pass this experience down the line, very awesome! This job will not be inspected but I want it to last and be safe. Thanks Again.


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## joewho (Nov 1, 2006)

Mac, 

Bud hasn't been back to answer, but I talked to him in pm earlier. No, it's not the same as fiberglass mesh tape. It's alkalai resistant.


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## MacDoe (Nov 18, 2006)

I must extend my apologies for my last post, as I got caught in the excitement of the fact I checked here before wasting my efforts, anyways, sorry if I offended anyone. We have removed the drywall mud from the dens-sheild as you have vehimately suggested. I must admit that I almost said to heck with it and left it the way it was, but then why would I have asked? I thought that it would be to much of a risk to damage the dens sheild removing drywall mud rather than procede and hope for the best.
However, I tried the tape edges and they pulled off quite nicely, as well, the water and sponge worked great and I did not have to put much water to it at all like I had feared. I am happy I listened.
So now I have a clean slate to work with and also piece of mind this job will be as correct as possible.
I went to give someone at home depot a hard time for this but, they played dumb like "oh we would not have told you that"
I did mange to get a copy of the revised instruction paper that is stuck to the back of each dens sheild board. It says to use woven fiberglass tape and embed with tile bonding material. It also goes on to say that if you have cut outs of any kind to use an elastomeric caulk, flexible sealant or tile setting material to prevent penetration of moisture.
SO I will use a kitchen a bath caulk, 100% silicone that is mildew resistant and permanently flexible. Would this be O.K to use on all the joints?, I did not dig the drywall mud out of the cracks so I am thinking the silicone would definately work well to seal the board with the fiberglass tape? only wondering what the omnigrip will do as far as bonding to silicone? I thought that silicone was very slippery in nature and might not be a good substrate for omni grip to adhere to, but it also seems to me that omnigrip is kind of like a synthetic mortar, so maybe would work well together? I would not need to use much silicon, maybe just enough to hold the tape in place until tile is set. 
I have surfed around to find some info out for the omni grip tile adhesive. I found a similar story to mine for a couple that on the advice of home depot workers told them to use this product to lay floor tile. They went with the advice and sounds like had to redo their floor at extra cost to them. Home Depot played dumb with them and only offered to refund the cost of the omni grip but thats about it.
I was fortunate enough to get a second opinion from another home depot employee on another visit, I am not sure how he knew not to use this stuff on the floor and the first guy did'nt,but, he did mention that he had heard the professional floor tile guys would not warranty work done on floors with omni grip. I sure hope it works on my walls and celing.
By the way I was wondering how to do tile on a ceiling? Thank You


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## joewho (Nov 1, 2006)

It says to use the caulk on cutouts, not joints. Just use the tile embedding material to bed the tape down. And in the cracks. I wouldn't use silicone anywhere other than cutouts.

I'm just a painter, so I have no advice on omni-grip, but I sure would talk to someone at a tile store or someone who would know for sure.

I'm glad you took your time, re-read the posts and followed up on information.

People ask, we tell them, and they don't like the answers, that's where the headaches start.

Good luck. Sorry, I can't give advice on tiling the ceiling, but I'm sure if you dig, you'll find the answer.
Yours
Joewho


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## MacDoe (Nov 18, 2006)

Thanks again


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