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Ideas From Ed: Not Afraid of a Little Hearth Work

Updated: Nov 23, 2020

Ed is a do-it-yourselfer who is happy to share some of his ideas and experiences in this monthly column.

I thought this month I’d show you how I tackled the project of installing some tiles onto the hearth area of a fireplace.  I’m not a tiling expert, but it came out pretty well.  This area was stripped of the original tile work many years ago, and I had to use the few remaining pieces from the floor to replace damaged and missing ones on the vertical facade of the fireplace itself.  The original tiles were not able to be found after several years of searching, so I decided to install new marble tiles in a contrasting color (white).  Here’s how the hearth area looked before starting the repair:

First of all, there had to be some decisions made regarding the type of tile as well as the size.  Tile choices include ceramic, porcelain, and marble.  I chose marble, and used 12″ by 24″ main tiles, plus trim tiles for a border.  The area is 60″ wide, so the tiles would need trimmed to make room for the spaces between them, as well as the edge tiles.

I decided to remove the mantle to make the floor area more rectangular and easier to fit the tiles onto.  Once it’s back in place, everything will have a nice, finished appearance.

If you’re doing something like this, I’d suggest purchasing all of the needed materials (tiles, thin-set mortar, grout) from the same place.  If the store salesperson seems knowledgeable, use his/her help to make sure you have enough and compatible materials, so the project will go smoothly.  Don’t forget to purchase a few extra pieces, as some may get broken or colors don’t quite match, and you’ll not want to have to run to the store again.

Some tiles can be cut like glass, scored and snapped.  Others can be cut and ground smoothly using an abrasive blade in a saw.  It was recommended that I use a wet saw with a diamond blade to cut the marble tiles being used.  A wet saw can be rented from most tool rental places, but I bought one a few years ago when I did a bathroom floor.  It was a cheap tool, adequate for a homeowner or a once-in-a-while small project, but if you’re doing a lot of cutting, you’ll want to rent a professional version.  A wet saw is basically a table saw with a diamond blade that somehow stays water-lubricated while in use.  In my home version, there’s a water pan that sits directly under the blade so that the lower blade section is actually submerged.  All I can say is that you need to move the material through the saw blade slowly and steadily, taking care not to twist or change direction.  Sometimes free-hand cuts are unavoidable, but try to use the saw’s fence and/or miter gauge to guide material when you can.  Here’s a pic of my tile wet saw:

I selected the position of each tile relative to the next one so that the colors and patterns looked best.  I also chose to lay out the pattern to minimize the amount of cutting, and to enable the cut edges, for the most part, to be hidden under the fireplace front.  Thus, any small chips or cutting errors would not show, and the nice, square factory cuts would be presented as much as possible.  Again, in this particular case, that meant using full-width pieces for the inner three, and cutting only the outer edges of the outer tiles (all tiles had to be cut to length, though).  The cutting was necessary so that five 12″ tiles, plus the grout spaces between them, plus the outer trim pieces, would all fit into the 60″ space.  To help smooth any rough cuts, I attached a strip of emery cloth to a strip of wood and used it like a long, thin sanding block.  The marble sands surprisingly easy.  Here’s what that looked like:

And here’s it being used:

Speaking of grout widths, there’s no hard-and-fast rule about how big they should be.  However, usually floor tiles have wider spaces than wall tiles.  You can buy a bag of tile spacers very inexpensively.  They are rubbery “X”-shaped pieces of a specific width.  When slipped between tiles until the underneath mortar has set, they maintain a nice, uniform spacing between tiles.  I used 3/16″ spacers for this project.  Here’s a close-up of the spacers:

As I cut each piece, I marked its location and orientation lightly in pencil on the reverse.  This was to nullify any issue with the hearth recess not being “square” or some other irregularly, as each piece was cut to specific in-place measurements.

It can’t be over-emphasized that a lot of test-fitting is needed to assure a nice appearance and good fit.  Here’s a picture of all the tiles and trim in place, with spacers between them, in a “test fit” without any mortar underneath them.  I should also note that the existing substrate where this was being done was already concrete, so no special cement board or similar surface needed to be installed prior to setting these tiles.

Once I was satisfied with everything, it was all picked up, the area vacuumed of any debris, and I started mixing up the thin-set mortar.  Directions are on the box for a reason, and if you’re doing work like this, I suggest you follow them precisely.  Here’s what I used and a picture of it stirred to a creamy consistency:

When the thin-set was ready, I dumped it into place, and then used a notched (toothed) trowel to smooth it out.  The size of the teeth determines the thickness of the mortar as the trowel edge spreads it.  That way, a nice even layer is applied.  Directions called for a ¼” tooth for this job.  When pressed into place, tiles should be gently wiggled in the direction opposite of the “lines” in the thin-set.  Here’s the thin-set ready for the tiles to be placed into position:

Once the tiles were in place and suited me, I left things alone overnight so that it set up nice and hard.  The next step was to pull out the spacers and grout all the joints.  Again, there were  choices.  Grout comes in “sanded” and “non-sanded” versions, and of course, many colors.  I wanted a white color.  If a sanded grout was used on soft marble, it would likely scratch things, as the normal installation method is to mix the powdery grout, and then apply it with tools like this trowel and this sponge:



Essentially, the grout is pressed hard into the joints using the trowel, in a motion that fills the voids but also covers the tiles, and the barely wet sponge wipes off the excess.  There are plenty of internet videos showing how to do that if you really want to learn the proper techniques.  When I bought the tiles, the salesman said for such a small project as mine, he’d suggest using a grout caulk that you simply squeeze out of a caulking gun, smear with your finger, and wipe off the excess (so you still need the sponge).  That’s what I chose to do.  Here’s the type of grout caulk I used:

There’s one more step, to help protect the natural stone from stains and such — applying a sealer.  Here’s what I used:

This is the project after reinstalling the mantle and cleaning things up.  Hope my project has inspired you.

Happy restoring!


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