The Ultimate Guide on How to Build a Tile Countertop
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Do you love granite slab countertops, but not the price? Do you need a countertop surface that can take a beating? Cash strapped with champagne taste on a beer budget–this was my dilemma back when I was remodeling my rental property. Learning how to build a tile countertop is one way to get your granite fix, flex your DIY muscles and keep your budget in check.
The following is a step by step instruction guide on how to build a tile countertop. It is packed with detailed explanations and photos to make your countertops withstand a 75 pound cookie jar hunter and spilled boiling water, while maintaining a beautiful surface. By the end of this post you will be a knowledgeable carpenter and tiler before you even think about going to Home Depot for materials. Let’s get right to it!
1. Install the cabinets.
Ideally you should have your cabinets installed prior to starting on the countertop. You want your measurements to be as exact as possible and not moving your supporting structure certainly helps. This eliminates any surprise measurements.
2. Measure off the final countertop measurements.
Let’s build a kitchen together to give us some real numbers on how to calculate the final countertop measurements. For example, if we have an oven next to a 24” cabinet followed by a 36” sink cabinet and a 12” set of drawers we can expect to calculate the width measurement as follows: 24” + 36” + 12” = 72”. Calculating the front to back measurement is slightly more complicated. Let’s assume the bases are 26” deep and we want the front edge of the countertop to extend 1-1/2” past the base cabinet. Our calculation comes out to 27-1/2″.
Once you determine the final desired measurements consider the additional tile covering steps: cement board, mortar and tile. Calculate the size of the plywood base by subtracting the 3/8” front granite tile, 1/8” for mortar, and 3/16” of an inch for cement board (HardieBacker 1/4″ is actually 3/16″). Here is the math for our example: 26” + 1-1/2” – 3/8” granite – 1/8” mortar – 3/16” cement board = 26-13/16”. Adjust the measurement for your materials. If you are using travertine it could be 1/2” tile. Or perhaps you want to use some scrap 1/2” HardieBacker (with an actual size of 3/8″) for the front edge.
The underside view of a DIY granite tile countertop after installation. I used scrap 1/2″ HardieBacker for the front edge layer of cement board.
These are just rough measurements for a perfect world. But walls are often not perfectly straight. This is why you have already installed the cabinets and are measuring reality. The same can be said for expectations of 90° corners if you have an L-shape or U-shape kitchen. If the wall is not straight (out of plumb) then there will be some gap on the side against the wall. This is one of the reasons to install a backsplash so that this gap is unseen and liquids will not spill behind the counter.
You may encounter other reasons for the measurement to not exactly match. Once the cabinets are installed you discover these surprises or perhaps they match exactly. In either case, the measurement will be correct.
Next, go through the steps outlined here in the previous post to determine your desired amount of countertop overhang. Add the overhang measurement to the size of the actual cabinets setup to get the final measurements.
3. Determine the thickness of the plywood base.
¾” is the recommended minimum thickness of the plywood base. However, if you want a thicker counter you can either go with a thicker plywood board or layer multiple sheets of plywood together.
4. Measure off the plywood board(s) and cut it to size.
When marking off the cuts on the plywood, strategically use the factory cut side edges for your front and one side edge. Those two edges are as close to perfect as possible. They will give you the straightest line to base the rest of your measurements and place tiles. The following two photos highlight which sides I would use the factory edge on in a couple different scenarios.
In the simple case above the easy answer for the best use of the factory edge are the two exposed edges. Even if your line is not perfect the ½” travertine tile backsplash along with the mortar attaching it to the wall will cover many mistakes.
In the example above, multiple plywood boards are necessary to create this L-shape kitchen countertop. I chose to use the factory edge in the front, of course, and the edges along the appliances which were sure to be square. The two pieces of plywood meet at a butt joint (touch perpendicularly) and are covered by cement board so the joint is invisible. There is also ⅜” of wiggle room on the back side thanks to the porcelain tile backsplash.
Glue and screw the boards together every 6 inches. Make sure the two boards are in direct contact at all points and there are no bumps. Optional: we went an extra mile and went a bit overboard on clamping as well.
Could we possibly use one more clamp? 😉
In addition, we stacked all the counters overnight and let the weight of the boxed tile help mash the new countertop bases together. Perhaps it was a bit extreme, but we get an ‘E’ for newbie excitement and effort!
If you choose to layer two boards together for a thicker base here are some additional tips. If the countertop is too long for one board or you are building an L-shape or U-shape you can overlap the boards so that the seam is not in the same place for both layers. This will not only strengthen the surface by creating a single unified surface, but also minimize movement underneath the tiles preventing any cracking from taking place.
An example of staggered plywood overlap. A larger overlap is preferable, but this plywood is staged to fit in a camera frame.
5. Measure off the cement board and cut it to size.
Using the same thought process as multiple layers of plywood, you want to overlap the cement boards on top of the plywood surface so that the seams do not match. Then, measure and cut the cement board with a skill saw loaded with a diamond blade. Again, consider which sides of the cement board are best utilized on certain edges of the counter.
In order to easily cut the sink portion place the predetermined cement board on top. Mark the portion needed for removal underneath. Then remove the cement board and cut the sink hole out.
You will also need to cut small strips of cement board to mortar and screw into the front of the counters for the leading edge of tile. This is another area where I optimized where the top layer ends and the front strips begin:
I compare it to rock climbing where your rope system is your safety backup. Two holds are better than one. Again, it may have been over engineering on my part. However, anything to make the tile countertop more durable is a win in my book. It is only a subtle difference, but it impacts your measurements for both the top boards as well as the front strips.
6. Wipe off the cement board.
After cutting the board down to the proper size wipe it down with a damp cloth. Every edge should be dust free as well. This ensures the cement board properly attaches to the mortar on both the plywood side of the countertop as well as the mortar affixing the tile to the board. A layer of cement dust will prevent a strong bond and possibly introduce a hollow space under the tile where it is not attached.
7. Mortar and screw the cement board to the plywood.
The mortar is an additional step filling any gaps between the plywood and cement board, minimizing any movement of the tile surface.
Predrilling holes to attach the strips on the HardieBacker helps prevent the strips from cracking when the screw is fully embedded. By also presetting the screws in the strips you will not have to hold the strip in place along with the screw while waving a drill around in the other hand. This step does not eliminate drill waving, but now there is no balancing multiple items with the first hand, making the job just a little safer.
A sample of HardieBacker cement board strip for the countertop front edge with predrilled and preset screws.
Tape and mortar the seams where the cement boards meet.
8. Install Schluter KERDI or some kind of waterproofing membrane.
Counters will host any number of spills and splashes. Protect your work with a waterproof membrane to keep the underlying surface safe from liquids.
9. Determine how you want to affix the front vertical tiles.
Deciding how the front vertical edge of the countertop should look is a matter of taste and perhaps depends on the size of your tile. Should it be a full piece starting at the surface of the counter or should it be a smaller piece under the overhang of the top surface tile?
It might be easier to deal with larger pieces on the front side of the counter. However, there would be one more grout line on the horizontal surface. My second reason involved imagining the durability of a front only tile. Imagine the pressure on the tile if someone leans up against the counter, as we tend to do while leisurely brushing teeth or chatting with a friend in the kitchen. Repeat this thousands of times. If the top tile overlaps, more of the weight is applied on the top surface as opposed to shearing off a front only tile.
With this nerdy reasoning, I chose to overhang the granite tile over the edge and then put a smaller piece of granite underneath. Maximum aesthetics and durability are both satisfied by this answer. It is a win-win!
Of course, there has to be something that is harder: installation. If you go with a front only tile you can easily align the tiles with the factory edge. However, when overhanging the tiles on top you have to calculate the the amount of overhang. My rule of thumb is the thickness of the tile plus ⅛” for mortar (at this point the front ⅜” HardieBacker is already attached so it is not taken into account).
Another consideration is the size of the tile. If you are working with 12” tiles in a bathroom the depth of the countertop could be only two tiles. If your countertop is just a little too deep you could end up needing an additional sliver of tile in the back or applying an abnormally large strip of sanded caulk to match the grout. Another fix would be to set the tiles further back and fabricate wider strips for the front side of the cabinet to go from the surface to the bottom of the countertop. However, you would have an additional strip of grout on the front edge. Other arguments for and against this method are discussed above.
I had this problem with the kitchen coutertops. I opted for the sliver of granite tile in the back of the counter.
You may have noticed the front granite tile extends slightly lower than the plywood and cement board. It is not often when I am sitting at or below the horizontal surface of the countertop. However, just in case there are slight variances in the front cement board edge (because, let’s be honest, it is a pain in the ass to cut these little strips and mine are not perfectly straight) or a little extra mortar between any of the layers this little overhang will hide it.
10. Dry fit the tiles.
Dry fitting is dependent on a decent number of factors: size, shape, location of the sink, etc. For instance, if you are building an L shape countertop start dry fitting and take all measurements from the inside corner. This allows you to have more full size tiles and minimize the amount of cuts. If you start from another end the tiles will not match up with the corner and then you end up with the corner looking bad. If it lines up perfectly–go buy a lottery ticket!
This is an L-shaped counter with all measurements starting from the inside corner.
The arrows highlight the grout lines, showing the symmetry of the granite tiles surrounding the kitchen sink. Notice the matching grout lines in the tiles going down the front edge.
As for the front tiles, make sure they match the size of the top tile so the grout lines match up perfectly. For example, the tile in the middle of the sink pictured above is slightly smaller than twelve inches. So I cut down the front tile to match and the entire front line of tile exactly matches with the top tiles.
11. Fabricate all finished edges of the tiles
11a. Bullnose the front top edge of the counter.
Read this post for how to DIY your own bullnose profile edge on your tile.
The arrows are pointing the curved edges, a bullnose tile trim edge fabricated to soften the edges of the countertop and backsplash.
11b. If your tile comes with a 45 degree beveled edge fabricate a beveled edge on all sides of every tile.
This includes all cut tiles on the horizontal surface as well as all front vertical pieces. Please refer to the sanity saving bullnose tip linked here titled “Sometimes you need a small polished miter.” This is that time! 🙂 This ensures you will have a professional looking edge on all sides of the tiles, making them match perfectly. It also prevents an optical illusion of tiles being the wrong size even though you cut them to the same exact measurements.
The arrows indicate the 45 degree beveled edges from the factory on the cut tiles. The rest of the sides need to have the same miter fabricated to match.
12. Mortar the horizontal tiles in place
Once you are satisfied with the dry fit, mix up the mortar to the consistency of cake batter. Then start affixing the tiles to the counter. The trowel you should use is dependent on the size of the tile. A larger format requires larger trowel notches. For 12″ by 12″ tile I use a 1/4″ by 3/8″ tooth trowel.
Wipe down the cement board once again. A slightly damp (not soaking wet) surface helps the mortar fully attach to the board. It is also a last chance removal of any last bits of cement dust mentioned above in step 5.
When you are applying the mortar to the counter hold the trowel at a 45 degree angle.
Applying mortar to any surface: hold the trowel at a 45 degree angle and make sure you have full and even coverage of the entire surface.
Also back butter the tiles (trowel mortar on the back side of the tile). This important step ensures the entire surface is fully supported by the counter with no hollow spaces.
Backbuttering a tile to ensure full adhesion to the wall–it is the same for countertops.
One way to check if the tile is fully attached is by placing the tile as if it is the final time. Then peel it off to verify there are no hollow spaces. If there are small peaks everywhere you know you did it right! You may need to re-trowel the mortar back evenly on both the surface and the tile, but now you know you are good to go for real this time.
Make sure you do not splooge any mortar out when affixing the top tiles. Or really, that means make sure you notice right away and clean it up (it happens to me all the time!). If you don’t you will have to chip away the excess mortar before attaching the front tile (also happens to me all the time, but in sneaky small spots nowadays).
The same is true for any mortar coming up between two horizontal tiles. You need space for the grout and any mortar is much easier to remove while it is wet.
Even if it is 2 AM. Your 8 AM self will love you for taking one last glance with a wet cloth in hand as opposed to picking up a chisel to dig out your missed spots the next day.
13. Let the mortar set
Set the top tiles first and let the mortar dry before attaching the front edge tiles. My fear is I would inadvertently bump a tile out of place. Or I would tape the vertical front edge tile to the horizontal top tile causing the top tile front edge to sink as soon as I walk away.
14. Mortar the vertical front edge tiles in place
Use the same techniques used to set the horizontal tiles on the vertical front edge tiles. The only difference is gravity is now working against you. There are two ways to fix this. The first way is to clamp a ledger to support the bottom of the tiles and keep them in line. Make sure the ledger is level and then slide each tile into place.
The ledger board is level and clamped to the cabinet (drawers and sink face plate removed). The front edge tiles are backbuttered and mortared into place, resting on the ledger board.
Another way is to use tape to hold the tiles in place while the mortar is drying.
When attaching the front tiles use some kind of tape to hold them in place while the mortar dries.
Before you walk away double and then triple check to make sure all the tiles are level and straight.
15. Apply grout.
Mix the grout according to the directions. Be sure not to add too much water as it will lighten the final color. Then apply the grout, pressing it into place with a float moving at a 45 degree angle to mash the grout into place.
Also do not use too much water while cleaning the surface after applying the grout. This may also change the grout to a lighter color. Wait about 20 minutes before cleaning up the grout line and along with the excess grout on the tile surface.
I take a fist pass with a sponge, but after that I leave the grout line alone. I always end up using some elbow grease with a clean towel designated for grungy work to clean off the glossy part of the tile. Sponges always seem to leave the haze on for me no matter how clean the water is and how many times I wipe. I also learned the hard way the more I wipe with a sponge the more likely I am to lighten the grout.
16. Seal the grout.
Seal the grout after it has cured.
17. Enjoy and host a gathering to celebrate!
This is the longest and most important step! 😀
Tools:
- tape measure
- level
- circular saw
- saw wood blade
- saw diamond blade
- drill
- bucket
- mortar mixer (used to mix grout too)
- notched trowel
- wet tile saw
- diamond blade
- bullnose profile wheel
- slow variable speed grinder
- diamond polishing pads
- tile spacers
- ledger board
- clamps
- grout float
- caulk gun
Materials:
- plywood
- Liquid Nails (if multiple layers of plywood are required)
- screws (if multiple layers of plywood are required)
- cement board (HardieBacker)
- cement board screws
- fortified thin set mortar
- fiberglass tape
- tile
- grout
- grout sealer
Once you have the skills and tools building your own countertops is repeatable any number of times. A granite tile countertop is a beautiful, economical, and battle tested choice to update your bathrooms and kitchens.
Did you spot anything or need a clarification on a certain step? Fire away! As always, I am always up for learning a better way so please add comments for improvements! Remember, to ask a professional if needed on site.
