I've got a stone fireplace (floor to ceiling) of really ugly stone with large grout gaps between the stones. I tried painting the grout and also tried painting the stone (sample areas only). Neither are sufficient. I want to concrete over the entire wall surrounding the fireplace. Then, put tile around the fire opening and lathing strips to hold poplar boards everywhere else on the wall. I found a product for vertical concrete (Tru Pac V Mortar Conversion Kit) but the company said I have to scratch the stone first. The stones stick out anywhere from 1/2" to 1 1/2" from the wall behind it. What do I use to scratch the stone? Should the scratch fill in the gaps before I put on the concrete product? I've never worked with concrete or mortar before. Any help is really appreciated.

 

Welcome to the forums

From the sound of it, you'd be building this out pretty far from the existing wall. No chance of removing what's there first?

 

Making an irregular, rough stone surface smooth enough to install tile on is definitely not the best plan of attack. Way too much mortar (too thick in places) to apply in just one coat, and every additional layer presents a chance for bonding failure. You will not be happy when the tile joints start to crack, or the tile pull away, because the underlying material is unsound and letting go.

Far better to just pull the rock, install plumb and true tile backer board (on a framed out structure underneath, for some relief), and tile away using thinset. Add the grout and you're done.

 

BridgeMan's suggestion is likely be best (removal of the stone)

Or you would drill for Tapcons and screw cement board to the stone if you think you would get a flat surface.

 

Thanks for the info. Your feedback is REALLY helpful and based on it I think this project will need to be turned over to a pro. Sometimes knowing my concrete beginner's limitations and when not to DIY is the best advice there is.

 

You probably saved yourself a lot of grief and frustration by having someone else do the job for you. Just make sure to carefully shop for your "pro", as not all of them are equal. I'd stay away from the lowest bid, especially if it's a lot lower than the others.

But doing the demo work (removing the rock) is something you could do yourself, and could possibly save as much as $500 or more off the total price. It's not highly skilled work, just requires a few decent tools (3-lb. maul, heavy chisel or two, maybe a good prybar) and adequate muscle to knock enough mortar out of the joints to loosen each rock. A few pieces of plywood on the floor will keep the rocks from denting it when they break free and fall (watch the toes!). Try a small "test" rock near the top as an experiment--if it's within your capabilities, then ask all the contractors to give you 2 quotes, 1 for the total job and another with you doing the grunt work.

Good luck!