Tile over very old brick

[Diane J]

Need help! This fireplace is over 100 yrs old. The mortar while stable is crumbly. I’ve replaced 2 bricks (the 2 dark ones in the center) and repointed some of the mortar. I’ve shown a side angle to give you a view of how uneven the brick is. We are going to put a Jotul Oslo wood stove in front of this. We need the whole width (54”) and about 48” up for no combustible clearance. We want to tile the brick. I initially thought I could just smooth the surface with mortar or concrete, but it will just slide off. Installing metal lathe to put concrete then the tile on is out of the question, the mortar would not hold the screws. My next thought was to frame out the opening and put cement backer board over that, then I’ll have a smooth surface for tile. The wood you see is structural, except for the 2x4s set in the fireplace opening. Those are wedged in while I replaced the bricks, they will come out. My question is about non combustible clearance. Is cement board over wood studs, non combustible? Is there such a thing as metal studs?

 

[clancey]

There are experts on here that will give you the more experience information but what I say is don't try to use those bricks for anything for they are crumbing with big cracks in them..My house was built in 1926 and almost 100 years old and my chimney was behind dry wall and almost killed me by carbon dioxide when the sky overhung keeping in the dirty air..I had to put a liner in it to make it safe..Gosh people back then even plugged up chimneys with pie plates,,,Why not get some kind of a stove with its own piping that you can see instead of behind a fireplace that you would never be sure about--get a camera to take a real good look at it for safety reasons..old mrs clancey

 

[begreen]

Yes, there are metal studs.
Personally, I would strongly consider removing the entire thing, then install a proper metal chimney system. That would liberate a lot of floor space and would be much safer. It's a couple days work, but old brickwork like this comes down pretty quickly. My son and I did this in 2006. No regrets.

 

[bholler]

View attachment 280858 View attachment 280859
Need help! This fireplace is over 100 yrs old. The mortar while stable is crumbly. I’ve replaced 2 bricks (the 2 dark ones in the center) and repointed some of the mortar. I’ve shown a side angle to give you a view of how uneven the brick is. We are going to put a Jotul Oslo wood stove in front of this. We need the whole width (54”) and about 48” up for no combustible clearance. We want to tile the brick. I initially thought I could just smooth the surface with mortar or concrete, but it will just slide off. Installing metal lathe to put concrete then the tile on is out of the question, the mortar would not hold the screws. My next thought was to frame out the opening and put cement backer board over that, then I’ll have a smooth surface for tile. The wood you see is structural, except for the 2x4s set in the fireplace opening. Those are wedged in while I replaced the bricks, they will come out. My question is about non combustible clearance. Is cement board over wood studs, non combustible? Is there such a thing as metal studs?

No cement board over wood studs is not non-combustible. Yes there are metal studs available. And yes you absolutely could simply large that set mesh in the second coat of parge and tile it. The question is whether it's worth it or not. At this point you have it open it may be a better option to remove it. But that depends on lots of factors like the condition of the rest of the chimney the height whether it is supporting structure etc.

 

[Diane J]

No cement board over wood studs is not non-combustible. Yes there are metal studs available. And yes you absolutely could simply large that set mesh in the second coat of parge and tile it. The question is whether it's worth it or not. At this point you have it open it may be a better option to remove it. But that depends on lots of factors like the condition of the rest of the chimney the height whether it is supporting structure etc.

The chimney goes up through the second floor. We are having it 100% lined up to the top by a chimney sweep, that will be installing the wood stove.
I really hadn’t thought of removing it. It’s ugly to be sure but structurally it’s not going anywhere. We’ve already had it taken down to the roofline and rebuilt up.

 

[begreen]

Sounds very similar to our old chimney/fireplace. It was 2 story and I tiled in when we first moved into the house by placing a simple chickenwire mesh tacked to the brick, then did a base coat of cement over pre-dampened bricks and mesh. When I took it all down 10 yrs later, that was one of the more solid pieces of the fireplace.
Our chimney top was rebuilt after being skewed by an earthquake in 2005. The following year, I decided to take it all out in preparation for raising the house 3 ft and a new foundation. Starting at the top, the chimney down to the fireplace came out in a day. Then I tented off the fireplace area to a nearby window which was our brick dump. I kept a fan running exhaust to outside to keep the tented area under negative pressure. This was effective in keeping the mess constrained to the tented area. The fireplace came out the second day. Hearth demolition and cleanup happened on the third day.

PS: It was a good thing we took out the fireplace. Over the years remodelers paid no attention to clearance from combustibles to the chimney. The chimney had a couple of take-offs for previous stove connections. One was covered by wood and the other was covered with a layer of plaster.

 

[bholler]

The chimney goes up through the second floor. We are having it 100% lined up to the top by a chimney sweep, that will be installing the wood stove.
I really hadn’t thought of removing it. It’s ugly to be sure but structurally it’s not going anywhere. We’ve already had it taken down to the roofline and rebuilt up.

Make sure they use a properly insulated liner. I see nothing wrong with keeping it as long as it is structurally sound

 

[Diane J]

This is the second floor.
we really don’t want to tear the chimney out. So what are some suggestions for making the lower part look nicer, but is also safe. The mantle we tore out was way to small to be safe.

 

[bholler]

View attachment 280869
This is the second floor.
we really don’t want to tear the chimney out. So what are some suggestions for making the lower part look nicer, but is also safe. The mantle we tore out was way to small to be safe.

If you want it tiled parge it put metal lath in the second coat then tile. You could also do metal studs and cement board then tile stone brick veneer etc.

 

[Diane J]

Ok, I looked up parging, I guess that’s what I originally wanted to do but I didn’t know what is was called and didn’t know there is a specific mixture for this.
If I do this and then put porcelain tile over it, it would qualify as non combustible, correct.
The wall is very uneven the further you get from the fireplace opening. It looks like what I need to do is multiple thin coats, one video said about 1/2” thick. How long does it need to dry before adding another coat? When and how would I put the metal lathe in?
I need to thank you, you have been more helpful than anyone else I’ve asked.

 

[bholler]

Ok, I looked up parging, I guess that’s what I originally wanted to do but I didn’t know what is was called and didn’t know there is a specific mixture for this.
If I do this and then put porcelain tile over it, it would qualify as non combustible, correct.
The wall is very uneven the further you get from the fireplace opening. It looks like what I need to do is multiple thin coats, one video said about 1/2” thick. How long does it need to dry before adding another coat? When and how would I put the metal lathe in?
I need to thank you, you have been more helpful than anyone else I’ve asked.

Dry time will vary greatly depending upon humidity heat moisture content of the old brick. You will absolutely have to wet it down.

I would start with a coat to level everything out. Get reasonably level then scratch the surface to create a texture for the next coat to bind to. I would let that set for atleast a day then tack the wire lath up I usually just use nails. They are really just to hold it in place so you can work the mortar through it. Then coat it with mortar making sure you work it through the mesh well. If that coat is smooth enough you could tile over that. Or you may need another coat.

 

[begreen]

That's exactly how I did it for our old fireplace. I let the first thick coat dry for a week just to be sure. Then I followed with a coat of latex-modified thinset and set the tiles in that. This is how it finished out. The mantel was made of stock molding pieces. When I took down the fireplace, the tile and cement to brick bond were still very strong.