Fireplace Hearth
Summary: A plain concrete fireplace hearth can be covered with slate, tile or stone. Fireplace hearth designs need to consider the flooring adjacent to the hearth. Proper planning and your fireplace will look great.
DEAR TIM: I have an existing concrete fireplace hearth. Is it possible to cover this fireside hearth with slate? If so, is that a difficult task? Instead of slate, should I just install a hearth pad? I am really confused about what to do. Marianne C., Millis, MA
DEAR MARIANNE: You can cover the concrete hearth with slate, tile, stone or just about any other non-flammable building product. If you had x-ray vision, like some super heros, you would see concrete just below many of the hearths in older and even modern homes. Builders like myself install these concrete hearths as an extension of the concrete pad that the fireplace is built upon.
Usually the biggest challenge is planning ahead so the finished floor in the main part of the room transitions cleanly with the finished material on the hearth. Sometimes this is handled by creating a raised hearth where both the hearth and the firebox are higher than the finished floor in the room.
Slate will bond easily to the concrete hearth you have. I would use thinset adhesive, which is just a blend of Portland cement, silica sand and often some chemical bonding agents. The thinset is also fireproof.
Perhaps your biggest challenge in working with slate is that all cuts need to be made with a diamond wet saw or by hand using a carbide rod saw that fits into a standard hacksaw. You can't use a standard ceramic-tile snapper cutter with slate as the slate will fracture along an uneven line. It is possible to layout all of the slate and pre-mark all of the pieces to cut. Sometimes the slate store has a saw they will use to cut the pieces you bring back. Not all stores offer this great service.
Slate is a great material to use for a fireplace hearth for a number of reasons. It is a very durable natural stone, it is attractive and looks fantastic next to a burning fire, it is easy to clean and is available in a variety of mottled natural tones including red.
If you try to solve your dilemma with a hearth pad, I feel you may have a problem finding one the right size. Hearth pads are pre-made thin platforms that you just set on the floor. Some come covered with tile and I have seen some made with slate. Many of the hearth pads I have seen come in a few popular sizes. It may be very hard to locate one that covers your existing concrete hearth, and is also proportioned correctly for the room.
You can always resort to building your own custom hearth pad to cover the concrete already in place, but I feel all this effort should be concentrated on just installing the slate you want in the first place.
If you have any trepidation about installing slate, I would propose you making your own test hearth pad in your garage. Purchase a small piece of cement board that is perhaps 30 x 36 inches. Get some discount slate and just apply it to the cement board. Forget about making cuts unless you want to do it by hand with the carbide rod saw. My guess is that you will discover in short order that the slate goes down with little effort.
When working with slate or tile for a fireplace hearth, it is important to think about how the material will look against the other flooring materials that are adjacent to the hearth. If the slate butts up against hardwood flooring, a grout line between the slate and wood flooring often looks best. If the slate is surrounded by carpet, eliminate this grout line.
Be sure to seal the slate with a grout-release sealer before grouting the slate. This clear chemical helps minimize grout messes with slate. It is hard to grout slate because the surface of slate is uneven. The thin layers of minerals in the slate that create its gorgeous texture also are the bane of tile setters who struggle to clean all grout from the surface of slate.
The slate surface will be ready to walk on about 48 hours after the grout has been installed. It is best to keep the grout damp for this wait period. The presence of water will help strengthen the grout so it can be as durable as the slate.
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Comments:
Ann Baker 25 Aug 2008, 08:44
I am a relatively new subscriber and would not have read past comments.
Does anyone have a method for removing asphalt driveway sealer from a white
metal garage door? The last time I hired the driveway sealed, the
contractor got quite a bit on the garage door.
DI 10 Sep 2008, 20:15
I would like the answer to this question, also!
tim devitt 11 Sep 2008, 00:48
Tim ,I read your column and found it full of good advice. I would add a
couple of things if I may. 1) It is important to use a MODIFIED thin set as
it allows for the expansion and contraction of the hearth due to heat. 2)
Most natural stone companies have off cuts that they can't use that may
often be purchased at a substantial discount (Often cheaper than tile).
These make a rich looking hearth and come in a variety of colors to suit
any need. 3) As a stone/tile installer with 20 years experience I would
advise the use of an edging strip (like Schluder)with tile instead of grout
which may crack and pop out or buckle the hardwood due to expansion. Allow
a 1mm ~ 1/16 inch gap to the hard wood and fill with clear dap 230 to
avoid dirt build up. 4)If your fireplace burns real wood be sure to check
the local fire code for minimum dimensions of the hearth.
As always good blog keep it up! Tim
t. devitt 11 Sep 2008, 00:54
Ann and DI try mineral spirits to remove the sealer from the garage door.
Log your time and recover the costs from the contractor who I feel was not
diligent in their job. As every good tradesperson knows prep is 85% of the
job!
Debby 13 Nov 2008, 15:46
Hi,
I have some leftover slate pieces from a bathroom project. I would like to use random size pieces to create a surround on my fireplace. I lined them up in a random patter to see how it would look and love the look. It almost looks like stackstone. I am thinking of putting the pices close together but am thinking of leaving them grout free so it does look like stackstone. Is there any problem with doing this? Thanks, Debby
bob 13 Dec 2008, 19:17
I live in Michigan and needed some brick work done for my stone fireplace.
Well, like every easy project, this one turned out to get a little more
complicated than I originally had imagined. The whole plan looked great on
paper, but eventually I knew the building stone I had gotten wasn’t going
to be enough. I got some recommendations from a buddy of mine, but I
wanted to go with a company that has been around for a while and has a
reputation that they stand behind. Another friend of mine suggested
Lincoln Brick and Stone. I checked out their website
(http://www.lincolnbrick.com), made a couple of phone calls, and they
really put my mind at ease. The project, on its way to being a complete
masonry nightmare, wound up ending without incident. I would say “fun”,
but since when is installing a new stone fireplace fun? Just to celebrate
the hard fought victory over my stone fireplace, I had them throw in some
custom engraving to seal the deal. I was generally very pleased with the
work done by Lincoln Brick and Stone and would recommend them in a
heartbeat for anyone who wants to have a stone fireplace, but might be a
little reluctant to choose a company to use.
Kamala Duplessis 20 Dec 2008, 12:11
I'm looking for a stone hearth for my fireplace.
Fernando 25 Mar 2009, 04:17
Hello Tim,
I think your sight is great for "do it yourself" tips. Can you tell me how I can make a bed frame extension from a single bed to a double bed using the same single header and footer? Thank you! Fernando
Fernando 25 Mar 2009, 04:29
Hi Tim,
How can I build a sturdy driveway gate from wood. I was thinking of a two door gate. Approximately 5 foot long by 6 foot high with a slight arch at top across both doors. The driveway span is 10 foot. What is the best way to join the crossmembers? Thanks! Fernando
jeauxbleaux 07 Aug 2009, 05:50
Going to get a woodstove put in in the next few weeks. Where it's going
currently has laminate flooring that's still in pretty good shape, so I'm
reluctant to cut into the laminate to remove it for hearthpad placement,
especially since I may take the stove with me when I move. And because I
will probably want to take the stove and pad with me, I'd like to protect
and preserve the flooring under the hearthpad.
I'm thinking of building a hearthpad, probably 3/4 OSB, maybe with a 2x2 or 2x4 frame underneath, wonderboard, and some sort of inexpensive non-flammable something on top. But there's also the possibility I'll run out of time and just buy a hearthpad. So what should I put between the hearthpad and the laminate floor to protect the laminate floor? View all comments |
