Tuesday, September 14, 2010

The lava fireplace remodel revisited

Anne posted a comment to my fireplace renovation post, asking what tools we used to remove the "decorative" lava rock surface. The short answer: a hammer and a chisel.

We had NO idea what we would find under the rock. We took a wood chisel, pushed it against the grout, with the chisel angled towards the underside of a rock and tapped, tapped, tapped until the rock broke off. The grout - rough cement - was fairly soft and didn't take too much force to break it. We were just being very delicate at first. Once we got one stone off, we used the opening to get the chisel under the surrounding stones. We broke down and bought a chisel for stone surfaces (with a metal guard to prevent whacking the hand holding the chisel). Getting them off the stone fireplace face was the easy part.

The outer edges of the stone were applied directly on the drywall. Hard stone on soft gypsum makes chiseling impossible. We tried delicately removing the stone, but gave up. We cut the drwall alongside the stone and snapped it off, drywall, stone, and all. Then we had to patch the drywall.

I believe that code requires a 1-foot zone of non-flammable materials around the fireplace sides and 16 inches along the top (if you tackle this project, consult your code enforcement department and a fireplace expert!). In any event, we didn't want to create a fire risk, so we used cement board instead of drywall. It's harder to work with, but it can handle wet mortar and heat.

We cut the drywall back to the middle of the nearest studs, to give us a place to nail the cement board in place. The surface underneath the lava rock was not even - the builder used the mortar to level the surface AND to attach the stones. So attaching the mortar board was a challenge. We mixed up a small batch of concrete patch (some high-tech version that was fireplace compatible) and slopped it onto the fireplace. Then we slapped up the cement board and screwed it into place. The original idea was to tile over the fireplace, but the uneven surface would have to be completely evened out. We would have to lay an even bed of cement to prep the surface for tile (to even it out) - well, heck, that's half the job of stuccoing it. So we decided to just do stucco. Then we attached lath (wire mesh) with spacers, to support the stucco finish.

Demolition was the easy part. There was a risk we would cause serious damage, because we had no idea what was under the rock, how it was attached, etc. But we hated the lava rock (or, as I called it, the spider habitat and dust collector). We had tried painting, but painted grout lines look like crap, and painting just the stones - not the grout - was a very slow, laborious job. We were willing to pay a contractor to remodel it, but the contractor couldn't quote a reasonable price without knowing what was underneath. So we looked at the demo as starting the job for the contractor - though we ended up finishing the job, too.

If you consider tackling a fireplace remodel, be prepared to learn about flammability - this is NOT a job you want to screw up. Have funds available to hire a pro if you need one. Get help if you need it and be very careful to ensure the final result is safe. And be very, very gentle on the first stone - the firebox and chimney are probably made of brick, too, so a heavy hand will damage the brick structure of the firebox - and that could make the fireplace unusable and unsafe.