Handmade Tile Backsplash: INSTALLATION

When your tile is going to be a challenge to install flat and level…

…then you need to make the right install material choices! This post describes how to install custom handmade fireclay tile with uniform results that will make the result worth the high-end tile expense. This previous post explains why handmade tile is often challenging to work with, and this previous post explains how the design and layout was planned for the actual install described here.

So finally, this third post gets down in the weeds describing how to install irregularly sized handmade tile for even level results. As the NFL playoffs show, all the best pre-match gameplanning in the world can’t overcome gametime screwups in the clutch:

So if you’re interested in best practices to prevent installation mistakes for expensive handmade wall tile, then read on for tips!

Step ZERO: increase your outlet joy!

Installing a kitchen or vanity countertop backsplash means that you’re starting at bare drywall. And it’s easy to cut through drywall to access wiring. AND, I have never met a countertop that couldn’t use at least some additional electrical outlets.

In this case, the clients’ 1970s -vintage kitchen had just two outlets that weren’t particularly conveniently located. Whomever had installed the wall cabinets previously had at least added undercabinet task lighting. But there were no outlets conveniently located at the countertop perimeter for appliances like coffeepots that always live in these corners.

Now that’s a seriously sad lack of power situation!

So, add some outlets! It is super easy to add additional outlets on a countertop. Seriously, adding additional outlets to your countertops is a no-brainer easy thing to do for adding enormous convenience and additional value to any new backsplash renovation.

You won’t even need to patch the drywall afterward, since the backsplash tile will do this for you. Simply make sure that the patched-up drywall is securely screwed to the studs and completely level, and you’re good to go for tile install start.

Step ONE: choose the correct adhesive

It’s hard to beat plain basic unmodified thinset for most wall tile install projects. It works for both wet applications and also dry situations like backsplashes, and also works for adhering tile to both concrete backerboard and drywall substrates. It’s also the least expensive tile adhesive at ~10$ per 50lb bag.

However, just about any thinset will begin to “skim over” pretty much immediately after being spread on drywall in a thin coat. The drywall will immediately start sucking moisture out of the thinset mix from behind, while the open air will cause a dry film to develop on top. Both of these things will prevent a good bond with the tile and can result in tiles literally popping off the wall once the thinset fully cures.

Normally you can work around this thinset limitation by working quickly to stack tiles on the wall before the thinset gets too dry. But remember that handmade tiles have finicky size, shape, and thickness variations that makes it nearly impossible to slap them up quickly with good results.

As a result, mastic is the best choice for a backsplash tile install that will require a long working time to get each tile perfectly placed. Mastic is basically organic glue, and so not appropriate for a wet area application like shower or tub surround walls. However, a countertop backsplash is basically decorative. If your kitchen counter ever sees enough moisture to dissolve mastic adhesive, then you’ve got WAY bigger problems than just having to replace a backsplash!

For this project I used basic “Mapei Type 1” mastic, which has an annoyingly long dry and cure time (48-72hrs, as opposed to overnight for basic unmodified thinset) but also stays workable for a long period of time so you don’t have to worry about it skimming over on a wall. Basically this was a tradeoff between workability (giving lots of time to play with getting perfect placement of each individual tile during installation) and cure time (requiring a full weekend of letting everything dry and cure before grouting).

Step TWO: backbutter each tile

Any thinset or mastic adhesive works by doing two things. It must be firmly bonded to the substrate, and it must be firmly stuck to the tile.

For a wall tile backsplash install, firmly bonding mastic to drywall means getting a nice full even layer of the mastic spread onto the wall. Simply trowel it on in a nice even continuous layer without any thin spots (this is where having a dead-level substrate really helps). On this project, I used a 1/4-in notched trowel to give enough room to level each irregular thickness tile for an overall flush install.

Firmly bonding the mastic to the back of each tile can be more difficult. Some tile types like solid porcelain or glass are perfectly flat and very dense with few or no pores on the backside. These types of tiles will therefore push fully and evenly into the adhesive. However, natural stone and ceramic tiles made from a clay base are often not completely flat on the backside and have a very porous backing. Just pushing these tiles into the thinset will often leave voids and trapped air that prevents a good lasting bond. The LAST thing you want is to have poorly adhered tiles start popping off the wall as the mastic cures.

The solution is back-buttering, which is exactly what it sounds like. Before putting each tile in place, first ‘burn’ a thin layer of the mastic adhesive onto the back of the tile with a conveniently sized drywall knife. This fills all the little pores and seams on the backside of the tile for a tight firm bond with the wall. It’s also a pain to do, since it means more futzing with each individual tile before even putting it in place for extra futzing with grout line gaps, etc. However, back-buttering is essential for ensuring a trouble-free installation for handmade ceramic tiles with a porous clay base.

Step THREE: keep the tiles random

Any handmade ceramic or natural stone tiles will vary a bit in appearance from tile to tile. This is a feature, but only if the variations appear to be truly random when the tile is actually installed. Human brains are really good at perceiving patterns even where they don’t exist. This is why making the appearance of randomness takes actual work.

It’s not enough to just shuffle tiles and hope that the result seems random to the eye. There is a difference between randomness and chance. For example, if you flip a coin 10 times then you’re actually just as likely to get ten heads in a row as you are to get exactly five heads and five tails in a row.

Do you want the variations in your finely handcrafted ceramic or natural stone tile to appear random? If so, then don’t leave randomness to chance! Examine EVERY tile before install to make sure that it doesn’t contribute to an accidentally emergent pattern.

Step FOUR: grout carefully

Ceramic tile is usually the easiest type of tile to grout. Grout haze does not adhere well to smooth surfaces, which is why ceramic tile makes a great easy to clean backsplash. However, this particular handmade tile had a cracked glaze surface that could have absorbed grout to make for a really ugly finish. The presealed Mapei Ultracolor FA grout that I always recommend is very gentle on tile and doesn’t leave a difficult to remove haze. But it’s also really good at penetrating into even small joints and cracks, and so can fill natural stone tile pores and handmade tile cracked surface glazing for a not great finish.

So if you need to protect a natural stone or other finicky tile surface (like a textured tile, matte finish tile, etc) when grouting, then use a grout release product. It adds a few hours of install time to spread a couple layers of grout release onto the installed tile and wait for it to dry, but the water soluble waxy coating it provides will ensure that the grout won’t discolor the tile surfaces.

Grout release is like insurance. If you think you even might need it, then get it!

Step FIVE: caulk precisely

Unfortunately, you cannot pack grout into 90deg inside seams along countertops. Same goes for tub surrounds and inside tile seams in showers. Grout is fantastic for staying in place between tiles on a flat surface. It will, however, eventually crack and crumble out of inside joints. So you need to finish these installations by installing caulk in the seams. Caulk is flexible enough to expand and contract a bit even when fully cured, and so will fill seams without cracking or chipping out.

It is however important to use the correct caulk and install it with precision. DO NOT just go to the big box paint section and get plain ‘ol painters caulk or even straight silicone caulk! Instead, go to the tile section and get proper color-matched grout caulk. Both Mapei and PolyBlend (the two big grout manufacturers) have specialized caulks that match every grout color they offer. For a kitchen countertop backsplash that will see a lot of cleaning over its lifetime, sanded siliconized caulk is a great choice. This is a very durable caulk type that’s both waterproof (so it’ll resist stains) and that can hold up to any scrubbing (because it’s very dense with the added sand content).

It’s also important to install the caulk with precision. DO NOT just squeeze a bead into the seams, lick your finger, and hope for the best. This will result in an uneven mess that’ll make an otherwise fantastic tile job look like junk. Instead, take the time to carefully mask off your caulk joint lines with tape. The prep will be an annoying pain, but the actual caulking will then be a breeze. With everything masked off, you can simply smooth all the seams to precise thickness without worrying about the mess. Once everything is smoothed out, simply peel up the tape for perfect lines.


A careful installation is what makes for a perfect finish. In this case, “perfect” meant precise randomness. Each handmade tile was slightly different from all the others, which purposefully counterbalanced the otherwise regimented precision of the rest of the 1970s -style vintage kitchen design.

Welcome to Austin Texas, where good taste from every era has a home!