I have an INTERIOR coquina rock fireplace wall that I hate, hate, hate. Background information: Coquina rock is a very porous rock made of lots of little seashells compressed together and is found in Florida. It is extremely porous (think lava rock). I've decided to try to paint it and expect to use a several coats of bonding primer before I paint. The "mortar" or concrete, or whatever the buffoons (who thought this would be really cool back in the eighties) used to construct this is often non-existant on the face of the rock wall. It appears as if they wanted it to look like the rocks were free stacked as no mortar is present over much of the wall and this leaves really deep holes between the rocks in most places. None of the rocks are loose. It is just a really ugly brown rock wall and the surface is alarmingly uneven with some rocks jutting out maybe 4" farther than others. So now my question/s: What to do about the cracks? Most cracks and holes are too large to caulk; some are too small. Would you attempt to mortar all of the cracks before painting? What kind of mortar? Since all of the cracks are irregular, normal tuck and point is just silly, isn't it?
So I jumped on YouTube to refresh my memory on dealing with this.
For a while people were just demo-ing them altogether.
You seem to implying an intent to fill and cover the entire surface for a smooth effect. Those projects tend to use preblended colored mortar (just add water), and they trowel it into all the cracks and holes.
The newer thing I found was people chiseling down and whitewashing (with a sprayer) the stone. Because of the application it covers all the surfaces for a very uniform updated look.
I would definitely send you to YouTube for more ideas if nothing else. Search "Fireplace Makeover"
STOP. please, just stop. I am not allowing you to do this.
someone has to tell you frankly that is the absolute worst solution. First of all, it is going to be impossible to make a flat wall with mortar and no matter how many coats of primer if there are rocks that are sticking out 4 inches. it's impossible. no, like really, really impossible. also, it's going to devalue your home. Have I mentioned some people actually like coquina? imagine trying to sell your home and having to explain to the potential buyer that the bumpy purple wall in the center of the living room used to be a nice coquina fireplace.
So, consider this: cover it with drywall. make a simple frame out of plywood that sits up against the coquina wall and just put drywall on it and paint it. whatever color you like. it's your wall, hell you could even glue nice dark laminate flooring onto it. with some nice framing around the edges? make it look good. I know you can do it. you will save yourself time, money, and time. also, you can destroy the facade wall and remove it within a day if it gets botched or when it comes time to sell your property.
Better yet leave it alone, it looks fine.
Unfortunately, I think your only choices are leave it or demomolish it. I don’t think building a facade wall will work, you may protrude too far past the trim. People will wonder what you are trying to hide behind that crazy wall that sticks out. Painting and filling isn’t going to work. I’m sure in your mind’s eye, you see a gorgeous smooth stone wall, painted the perfect color. What you’ll get is a disgusting blob wall with caulk, sea shells, and mortar. You can have a gorgeous smooth painted wall, you just need to demo this one and start from scratch. There are a ton of wall covering options. Faux brick, faux stone. I’ve seen some that look so real, it would fool a mason. Good luck.