Four summers ago we rebuilt our kitchen hearth. This year we tackled the living room hearth.
Here is what the hearth looked like before we started this project. I had added a ceramic-tile-over-cement-board extension in front of the rather shallow brick hearth in order to meet building code for wood stove clearances. This picture was also taken before we had granite installed surrounding the firebox.
Here we are getting started. We have moved the 325-pound wood stove aside and have removed the tile from the hearth extension. You can also see how much better things look since we had the granite surround installed several year ago.
The brick hearth was dry-laid, as was the stone floor in the firebox, so deconstruction was pretty easy (if not a little dusty!) After removing the bottom board you can see straight into the cellar and that over half the width of the brick hearth was over the thick stone foundation of the house. We also unearthed an interesting find: a rusted metal cylindrical canister, about 1½” in diameter and 2½” long.
Inside the canister was a collection of newspaper and magazine clippings, some dated 1889. They are almost all concerned with ladies’ skin and health issues, information on various tinctures, salves, etc. And about those prices: $1 in 1889 would be about $24 today, so they were not cheap! Our house was built in 1835. Was the hearth rebuilt in 1896? Or perhaps a young lady hid the canister in the existing hearth (it was dry-laid so it would have been easy to remove/replace a brick). We’ll never know for sure.
One of the challenges in renovating an old house is that nothing is square, level, or plumb. It took several rounds of tweaking with this cardboard template to achieve the exact location for the new hearth, which is both wider and deeper than the old one.
A fair amount of work with the circular saw, reciprocating saw, hand saw, belt sander, and chisel was required to remove the flooring and true the hole. The next step: cut out the beam running through the middle (this beam ran along the front of the original hearth). Here you can see the tops of the 2×4′s that I screwed onto the beam to keep it from falling down when I cut it. In the foreground, you can also see the ‘tool multiplication effect’ that always dogs a project of this scale.
The beam removal went smoothly. You can see the temporary diagonal bracing I put in to help support the floor until the new framing is installed. You can also see the end of the existing I-beam that is an important component of the support structure for the new hearth.
The new framing is complete. I used double 2×8′s for the new joists, with the ends resting on the stone foundation and joist hangers for connecting with the cross joists. The interior of the hole has a 2×4 ledger screwed in place. I cantilevered a 2×8 from the I-beam for a center support; the center cross-beam is a 2×4.
The plywood (left over from the 2005 Apothedairy project) has been screwed in place. The rebar is keyed into the existing stonework. The tar paper is in place over the dirt/rubble floor of the firebox. 12 bags of concrete mix are at the ready. The goal is a 3½” level slab, with ½” cement board thin-set-mortared on top for a smooth base for the granite slab.
I decided to mix the concrete outside in the wheelbarrow 2 bags at a time, then wheel it in and dump it. Concrete is heavy and messy so we prepped by taping down cardboard and using plywood scraps on top for a lane and outside as a ramp on which to roll the ‘barrow.
I was pretty pleased with myself for how good the pour looked (and for my home-made bull float that you see here). Once it set, though, I discovered that it had a pretty severe hump in the middle. I ended up mixing and spreading small batches of mortar to try and level it out. This was only partially successful, and after discussing the situation with the granite installers, we opted to nix the planned cement board overlay and have the granite slab installed on a fresh bed of mortar.
The installers (A & S Marble Granite) did a fantastic job cutting and fitting a 1¼"-thick single slab around the mantle molding and into the firebox. The stone we chose is Giallo Fiorito, a yellow granite from Brazil. It is the same granite we used around the firebox, though a slightly different shade.
Kirsten wanted to paint the interior of the firebox to brighten it up. I was skeptical about using latex paint so close to a hot stovepipe, but I applied my Google-Fu skills and unearthed the research paper “NIST GCR 02-832 – Flammability Characteristic of Painted Concrete Blocks” which describes lab experiments on, yes, painted concrete blocks. The lowest ignition temperature they found for latex paint was 1200°F — plenty of leeway over the normal 300° – 550° operating flue range — so I painted it using the same off-white color of the mantel trim.
The finished project, just in time for the heating season.