Installing outdoor tile is an incredible way to transform any outdoor living space. Tile is durable, affordable, gorgeous, and relatively easy to install. That said, improper installation can cause anything from a disappointing appearance to a rapid deterioration of the tile surface. The result? A whole lot of wasted time, effort, and money. If you want to avoid this fate, read on to learn exactly how to install outdoor tiles on a terrace, courtyard, and more yourself.
Working With Tile
Tile requires the use of special equipment, such as a large and expensive tile saw. Fortunately, these tools can be rented for a reasonable day rate from many home improvement and equipment rental companies. If you're lucky, you may even have a friend or family member with a tile saw they're willing to lend you for free. In either case, see if the saw's owner is willing to give you a demonstration of how to safely and effectively use the tile saw if you haven't used one before.
Another consideration is the type of base you will be installing the tile onto—the substrate. One of the most common, and easily worked, substrates is a concrete slab, but cement board and similar exterior-grade materials can also be used. The method outlined below assumes you will be working with concrete, but it can be used on most other tile substrates, as well.
When to Install Outdoor Tile
It's recommended to install outdoor tile when the outside temperature is between 50°F and 100°F. Colder temperatures will increase the cure time and compromise the strength of the mortar and grout holding the tiles in place. Higher temperatures can cause the mortar and grout to cure too quickly, resulting in a poor bond.
Equipment / Tools
- Mortar trowel
- Grout trowel
- Grout sponge
- 5-gallon bucket for mortar and grout
- 5-gallon bucket for grout sponge
- Masonry mixer (hand trowel or masonry mixing paddle and power drill)
- Tile saw
- Tile spacers
- 6-foot or longer spirit level
- Chalk line
- Scraping tool (masonry chisel or hard scraper)
- Knee pads (optional)
- Power washer (optional)
- Self-leveling compound (SLC)
- Masonry caulking
- Concrete Patching Compound
- Crack isolation membrane (optional)
- Degreaser such as trisodium phosphate (TSP) or muriatic acid (optional)
Prep the Concrete
Your slab needs to be free of dirt, debris, oils, and other residues for your mortar to properly set and cure. Thoroughly clean the slab by scrubbing with a stiff broom and water, or spraying with a pressure washer. You can also use a degreaser for tougher stains. After your initial wash, use a garden hose or pressure washer to spray off any lingering residue and allow the slab to completely dry.
Fill and Level the Concrete
Cracks in your slab can transfer (or telegraph) to your tile over time, and unlevel portions can result in water pooling on the tiles.
Check for unlevel areas by placing a large straight edge (the spirit level or a straight 2x4) over the entire surface of your slab. Identify any areas where the gap between the straight edge and the slab is greater than 1/8-inch, and fill in these spots with self-leveling compound (SLB) or other concrete floor leveler.
Next, fill in cracks with a masonry caulking or a crack isolation membrane depending on the amount of cracks present on your slab. Masonry caulking is best for slabs with a marginal amount of cracks, while a large amount may justify the use of an isolation membrane across the entire surface. In addition to the cracks, the expansion joints (large gaps) in the slab should also be filled with masonry caulk.
Finally, fill in any holes with a concrete patching compound.
What Is Crack Isolation Membrane?
Crack isolation membranes offer a barrier between the tiles and substrate so cracks in the substrate don't telegraph into the tiles. Isolation membranes are available in rolls of rubbery fabric sheets or spreadable slurry mixtures.
Lay out the Tile
Laying out your tiles in advance (dry-laying) will help to ensure that you have enough tiles to finish the job, and allows you to make any specialty cut—as needed to fit against walls and around corners, for example—before mixing and spreading the mortar. Doing so will help to maintain your workflow once you start laying the tile by helping you avoid the need to run to the store for more tiles or stop to make cuts.
At this point, you should also lay out where your expansion joints are going to go. An expansion joint is a 1/8- to 3/8-inch gap between sections of tile that accommodates the natural expansion and contraction of the tiles when exposed to different temperatures. Generally speaking, there should be an expansion joint for every 12- to 16-feet of tile, and at any point the tile contacts a vertical surface such as walls or steps. Mark out these areas on the substrate using a chalk line.
Mix and Spread Mortar
Combine your mortar mix in a bucket and add the amount of water recommended on the bag of mortar mix. Mix the two together with a hand trowel or concrete mixer paddle attached to a power drill until the mixture is lump-free and smooth.
Once mixed, spread an even layer onto your slab using the flat edge of your mortar trowel, beginning at a corner or against a wall. Only apply enough mortar for 15 to 20 tiles at a time to prevent the mortar from drying prematurely. Then, use the combed edge of the trowel to create grooves in the mortar to promote proper adhesion to the tiles. Be careful not to mortar over the areas you marked out for the expansion joints.
Lay the Tiles
Apply an even layer of mortar to the underside of the tile (this is called back-buttering), and gently press the tile onto the mortar until it's well seated. Continue laying tiles side-by-side, and place spacers between each one to produce a consistent gap for the grout in the next step.
Occasionally check that the tiles are flush to each other and level throughout by resting a spirit level across the top of several tiles at a time. Continue laying tiles, applying spacers, and checking for flush and level until the area of mortar you spread is covered. Continue spreading mortar and laying tiles until the slab is covered with tile. Once complete, wash off your tools and clean out your bucket.
Allow the mortar to set for the length of time indicated by the manufacturer. This can be anywhere from 12 to 48 hours, depending on the product and weather conditions. When it's dry, remove the spacers and use a scraping tool to remove any excess mortar that squeezed out of the gaps and onto the surface of the tile.
Grout the Gaps
Mix the grout in a bucket using the recommended ratio of water and grout mix until it reaches a smooth, clump-free consistency. Use your grout trowel to spread the grout mixture into the gaps between the tiles until they're completely filled. You should not, however, fill in the expansion joints with grout, since they need to be filled with a flexible masonry caulk.
After 20 to 30 minutes, fall back to the first tile you grouted with a bucket of clean water and a grout sponge. Wring out your sponge until it's damp and not dripping any water. Using too much water can cause discolorations in the grout.
Gently wipe away any excess grout on the surface of the tiles using a circular motion, and avoid wiping in the same direction as the gap. Otherwise, you risk pushing the grout out of the gap. Once the sponge gets dirty (i.e. it leaves a residue behind on the tile surface), wash off the sponge by dipping it back into the bucket and wringing it once again. It may take four or five passes with the sponge to completely clean the excess grout.
Continue the process of grouting and washing until all the tiles have been grouted, and then caulk in the expansion joints.
Outdoor Tile Installation Tips
Installing tile can be a labor-intensive and time-consuming process. While it's possible to complete this project with a single person, having two people can make for quicker and easier work. This is especially true if you're working with particularly large and heavy tiles that might require two people to move.
Even with smaller tiles, a second person can be helpful when spreading the mortar and grout. For example, one person can spread mortar while the other lays tiles behind them, and one person can spread the grout as the other cleans the tiles with a sponge.