How to Install a Slate Backsplash

For months now we have been working on finishing up our kitchen. All we had left was installing the backsplash, refinishing the floors, and hanging the new light fixture. For almost two months the kitchen sat untouched, all because the backsplash needed to be installed. Due to my husband's work schedule, he hadn't had time to work on installing it.
The time started to get closer and closer to the floor refinishing date and I knew something had to be done. We didn't want to have our floor refinished and then risk the chance that we could drop mortar or grout on them. If you remember from posts back, the backsplash was just the Hardi Board.

Finally, one weekend my husband had off I asked him to teach me how to install the backsplash so I could work on it when he was working. It was a great lesson to learn and I found out that I might be slightly better at installing a backsplash then he is. (I shouldn't say this bc he will make me do all the tiling from here on out!) He even commented on how nice the backsplash I installed looked. However, I did have the easy walls, he took the tough ones.

We tiled with natural slate, which is a whole different animal in itself. The pieces all are different shapes, thicknesses, and sizes. Slate splinters very easily and that can become quite the headache!

To start a backsplash, you must first make a pattern. We wanted something different, not just normal squares going across the wall. With the help of a tiling store in town (Brodkeys- they were the best!) I drew up a simple pattern for the backsplash:

The next part is to mix up your mortar. The mortar can be purchased at any home improvement store. Mix it with water to the consistency between mayonnaise and peanut butter. Let it sit for about 5-10 minutes to get the air bubbles out.

You need some tools to get to get the job done and while the mortar is setting you can gather them together.
1. Wet saw, you can rent one if don't own one. You need it with slate.
2. Spacers, so you can evenly space out your tile for the grout. (The green things below.)
3. Sandpaper, to finish the edges that are exposed. I used 220 grit.
4. Masking tape, helps with lining up your cuts on the saw. Also, it help prevent corners from splintering when cutting the slate.
5. Cardboard, to make templates.

The cardboard is something we made up. When getting around a power outlet, it's easier to make a template out of cardboard to know how to cut your tile. It saves LOTS of time!
Before you start cutting pick out your tiles. My husband did not do this (which why my walls might look better) and I was very particular about this part. Slate is all different thicknesses, sizes, and colors. I wanted the color to be the most even and the thicknesses not to differ so much. It will help with grouting later on.


Grab your tile and apply a liberal amount of mortar with a trowel and use the rigid edge to scrape off the excess. Be sure to clean any that fall off the sides.

The trowel should make the mortar look like this. The stuff flowing over the edge, make sure you wipe that off!

Find the center of your wall and that is where you begin. I started with the small 4" tiles and lined one up right in the middle on the center line and pushed it right into place. Hold for a few seconds until the tile sticks. Then begin with your next tile and use the spacers in between each tile as your work. Start from the bottom up, so the tiles above have something to rest on.

Use the wet saw to cut around any power outlets you might have on the wall. Obviously wear your eye protection while using this saw.

Like I said above, making a template of your cuts with cardboard first works the best. Just place the cardboard template on the tile, trace a line with a pencil. Next take your masking tape and apply it right on the line. When cutting with the wet saw makes it near next to impossible to see a pencil mark, so the tapes help out. Also, with slate it doesn't seem to splinter as much with the tape on it.

When you get the to edge of the backsplash that is exposed, there will be a flat cut mark from the saw. Because our tile was tumbled on the edges, it made it look strange. I used some 220 grit sandpaper to smooth down the edges and shape them to match all the other tiles.

Once your wall is completely done you will need to wait 24 hours for it all to dry. Make sure to wipe off any excess mortar from the tiles. You want the tiles to be very clean!

The next day, or whenever you are ready, apply sealant to the tiles. Some people apply this after they grout, but I read online that slate will suck up the moisture in the grout and makes it a pain! I purchased this sealer from Lowe's for $26.99. It was very easy to use and dried quickly. I applied two coats.

When applying the sealer, I put some tape down and paper just so I wouldn't get any on the counters. The sealer wipes of easily, but I wanted to make sure not to get any on the counters anyways. The finished results, below, show how it slightly darkens the color of the tiles.

Wait another day, to be safe, and you can apply the grout to the tile. Any home improvement store sells grout. They have several colors to choose from. Bring your tile and find one that matches your tile color the best. Mix the grout according to package directions to a consistency between mayonnaise and peanut butter. Again, let it sit for 5 minutes to get air bubbles out.

Using a grout float, push the grout into all the cracks. Some areas were difficult to fit the float so I used my finger.

Work in a small area at a time. We did about a four foot linear area, but there was two of us grouting and cleaning at the same time. If working alone, I would stick to about two feet at a time.

Wipe the tile clean and free of all grout. On slate this is tricky! I wiped them back splash down six times! I didn't want to apply the final seal with any grout left on the tiles.

I applied a grout sealer and one more coat of sealer to the slate. You need to let the grout dry three days before you apply the sealers. After the sealers, caulk where the backsplash meets the counter tops to create a seal. You don't want any water getting between the counter and the backsplash.

And my two finished sections that I did MYSELF!!!

Now I just need to put all the electrical plates back on and we are finished with this project!

The finished view, done by my husband :)

Up next... refinishing the floors. We are hiring this out, so should be done a pretty timely manor.

~Beth