tile and cement board questions

[onesojourner]

I am planning on tiling my painted brick fireplace. I was told that if I rough up the paint with a wire brush I should then be able to lay thinset over it and get a good smooth base to lay the tile. Does this sound ok?

Is there any kind of thinset I need to avoid? I will be using it on the fireplace and on the new mantel.

I have been trying to read up on cement board. I ran by lowes yesterday and all they have is hardibacker. I see durock mentioned on here a lot but I also read several threads that say durock has changed and its just about the same as hardibacker now. Does any one know where I can pick up something that will be good for a hearth? The stove we are getting has heat shields so I think anything will be fine but I don't want to under-build this either.

 

[Jags]

I am planning on tiling my painted brick fireplace. I was told that if I rough up the paint with a wire brush I should then be able to lay thinset over it and get a good smooth base to lay the tile. Does this sound ok?

Kinda, but not really. Look at it this way: If you are applying thin set over paint (even roughed up paint), you are depending on the mechanical bond of the paint to the brick for your strength. That mechanical bond typically lasts years with the weight of paint only, but when you add the weight of thin set and tile....well you get the picture. Its only as strong as its weakest link. If you want to trust the mechanical bond of the paint, then go for it. If you are looking really long term...maybe not the way to go.

Also, I am not too sure how well a cementitious based product is going to attach to a latex, or oil based product. Just don't know.

 

[dvellone]

The paint is the hitch here. Unpainted brick face would offer similar bonding qualities as cement board - the mortar joints would give yet more "bite". I wouldn't be able to put a lot of faith in a bond that has paint between it. Might last and might be problematic. On a vertical surface you can't beat applying diamond lath to provide great "bite" and strength for the bond. It's relatively inexpensive. You can use tapcons to apply it and rill them into the joints if they're recessed a bit so the heads will have a lower profile.

 

[dvellone]

Sorry, forgot... latex fortified thinset will improve bonding, and give you more "stickiness" for a vertical bond especially if the tile is heavy. Without the latex the thinset would work fine but is just a little trickier to use.

 

[rob bennett]

Follow the guidelines on the products. Durarock has a sticker listing how it can be used around stoves.

 

[wellbuilt home]

What i would do is take a chipping hammer and chip the paint off about 10% of the brick . You could just hit it with a hammer . It wont take long on a small area . Then you can skim coat over the brick with latex thin set . I would do 2 coats to build some thickness . Then tile it .

 

[Planeweird]

My three suggestions would be(which ever one you think you would be best at executing)

1) Gelatinous paint stripper will stick to the vertical surfaces and help to free the brick of paint enough to apply your thinset and tile.

2) A diamond bladed wheel for an angle grinder(used for concrete and masonry) will clear off the extra after you use the gel stripper or you can grind the whole thing.

3) 1/4" hardibacker or durock attached to the brick with short, flat headed Tapcons(short blue masonry screws)

 

[onesojourner]

I have a wire will for the grinder. it will destroy this paint and the surface should be plenty rough for the thinset I think. I will try it and let you know how it turns out. The guy at lowes just told me hardibacker is fine to use as a mantel.

 

[begreen]

It's been many years since I did this, but if I remember right I used a wire brush on an electric drill to clean the brick and removed any loose mortar. Then I attached 1" chicken wire to the brick surface. The brick got sprayed with a mist of water. Then the brick and chickenwire got buttered up with a smooth layer of thinset, not too thick. That was allowed to set for a few days. Then it was followed by another coating of thinset, that was leveled out with a notched trowel and the tiles were set into this. The chicken wire may have been overkill, but six years later when I pulled the fireplace out, the tile was still nice and solid.

PS: I just found this guide. There are some good tips here:

http://www.thisoldhouse.com/toh/asktoh/question/0,,20065453,00.html

 

[onesojourner]

Thanks for the link. I found another good link by TOH on there too the other day.


Does any one have any more thoughts on the cement board?

 

[begreen]

My main concern would be what permanently bonds the backerboard to the brick surface. This surface will constantly be heating, then cooling down. Backerboard seems like an extra step that will be depending solely on the tapcons to hold it up. It could potentially weaken the structure.

FWIW, I believe we can still get the original Durock cement board in some stores here. Ask for pure cement board, not the new generation stuff.

 

[Planeweird]

Begreen,

You would still want to apply thinset behind the backerboard and then tapcon through both layers. Same as when doing a floor.

 

[wellbuilt home]

I have a wire will for the grinder. it will destroy this paint and the surface should be plenty rough for the thinset I think. I will try it and let you know how it turns out. The guy at lowes just told me hardibacker is fine to use as a mantel.

Grinding paint in your house is very dangerous ! Don'T do it . The dust can linger for years . If you have small kids lead dust is very bad . chipping with a hammer makes limited dust (You can sweep it up ) and works good .
Th inset will hold to paint. We rip up vinyl tile that is glued to the floor all the time and replace it with ceramic tile . The problem you will have is with the heat causing the thin set to release from the paint . Be green has a good idea with the chicken wire but its is over kill . How big is your fire place ? What type of brick soft ( clay based ) or hard ? Interior brick work is not structural and the guys tend to work very dry. This makes a week bond on the bricks . Screws or nails may not hold and just crack causing other problems . Planet weird has a good idea , you could use paint stripper and strip the face of the brick but it will make a mess and wont leave the brick clean . John

 

[Planeweird]

Well Built,

I believe he said that he painted the bricks himself when he moved in, so that's gonna be a lead-free paint I'm sure. But in any other case I would agree with you.

Interior bricks can be soft but with a good pre-drilling for the tapcons, blowing out the holes to remove all loose brick dust, and then using a good masonry epoxy to lock in the tapcons, I think he'd be all set.

 

[onesojourner]

I'm not sure what kind of brick this is. how can I tell?

I found some wonder board at home depot. I assume that will work?

 

[Planeweird]

soft interior brick especially in an old home will scratch fairly easily with a nail or a knife. To see the difference, you can try scratching the brick on the exterior of a house and it doesn't do to much to it. Soft interior bricks are akin to slate tiles in how easily the scratch.

Wonderboard, hardibacker, durock will all work for attaching tile. The thing you want to check on is weather the one you choose is rated for heat. Ask or read the manufacturer's literature to be certain.

 

[wellbuilt home]

Well Built,

I believe he said that he painted the bricks himself when he moved in, so that's gonna be a lead-free paint I'm sure. But in any other case I would agree with you.

Interior bricks can be soft but with a good pre-drilling for the tapcons, blowing out the holes to remove all loose brick dust, and then using a good masonry epoxy to lock in the tapcons, I think he'd be all set.

I did not see any thing about who painted the the bricks on this thread ?
I have never had any luck with tap con screws either and i have try ed Manny time to use them .

All i can say is i install lots of tile and know that the chipping will work The best part is there is no reason to go to the store or buy Any thing . John

 

[Planeweird]

Well Built,

I believe he said that he painted the bricks himself when he moved in, so that's gonna be a lead-free paint I'm sure. But in any other case I would agree with you.

Interior bricks can be soft but with a good pre-drilling for the tapcons, blowing out the holes to remove all loose brick dust, and then using a good masonry epoxy to lock in the tapcons, I think he'd be all set.

I did not see any thing about who painted the the bricks on this thread ?
I have never had any luck with tap con screws either and i have try ed Manny time to use them .

All i can say is i install lots of tile and know that the chipping will work The best part is there is no reason to go to the store or buy Any thing . John

Ah, that's right. He posted pics of this mantle on another thread, so I knew the situation. My fault.

 

[onesojourner]

yep I painted over the white/blue sponge paint when I moved in. I am pretty sure that is post the lead paint days to.

 

[onesojourner]

new post here: https://www.hearth.com/econtent/index.php/forums/viewthread/39409/