How to Install a Saltillo Tile Patio
Saltillo tile takes its name from a region in Mexico that is known for its rich clays. The combination of raw materials and a hot climate ideally suit the area to the making of handmade tiles dried in the sun.
Saltillo tiles have an earthy, attractive quality. They also have drawbacks. Outdoors you can use them only in climates where they won't freeze. Also, their size, thickness, and consistency vary widely. This variety necessitates some special installation requirements.
Saltillo tiles are porous and must be rinsed to keep them from absorbing moisture from the mortar too quickly. Rinsing also removes residual dust that otherwise weakens the mortar bond. Don't lay saltillo directly on layout lines as you would ceramic tile โ set them back from the lines about 1/4 inch to account for their irregular edges. Seal the tiles with a penetrating sealer before grouting them. Otherwise the grout will dry too quickly.
What You Need
Five-gallon bucket
1/2-inch drill
Mixing paddle
Chalk line
Wet saw
Square-notched trowel
Beater block
Rubber mallet
Straightedge
Grout float
Caulk gun
Nippers
Grout bag
Sponge
Vacuum cleaner
Tack rag
Latex-modified thinset
Grout
Tile
Foam backer rod
Caulk
Spacers
Sealers
Establish Layout Grids
Setting saltillo tile takes more time than setting machine-made tiles because they are irregular. That means you might have to mix mortar in smaller quantities than you would for a ceramic project. To help organize your time, establish sections of nine tiles each and mix mortar in batches sufficient to cover that area.
Preparing the Tile
Step 1: Sort Tiles
Sort the tiles into piles according to thickness and flatness. This will help you get an idea of how thick your mortar bed has to be, and how many domed tiles you'll have to back-butter as you lay them.
What if a Tile is Domed?
Boxes of saltillo tile usually contain several that have a domed surface. Don't throw domed tiles away โ back-butter all of them at one time, starting in the center of each tile and working to get a level surface over the back, from edge to edge. Set the domed tiles aside and let the mortar dry before laying them
Step 2: Wet Tile
To slow the tile's absorption of moisture from the mortar, rinse the tiles in clean water and set them aside until the surface moisture dries or wipe off excess surface moisture. The tiles need to be slightly damp, not wet. Set them to dry in a rack or against a wall.
Spreading Mortar and Setting the First Tile
Step 1: Spread Mortar
Snap layout lines and mix up enough latex-modified mortar to cover an area about 4 feet square. Spread it on the slab (just short of the layout lines) with the flat edge of a trowel to a uniform thickness of 1/2 to 3/4 inch. Then comb it with a trowel with 1/2x1/4-inch U notches.
Step 2: Mortar Tile
Back-butter the tile with enough mortar to allow you to set it level with the other tiles. Comb the mortar with the notched trowel edge.
Step 3: Set Corner Tile
Set one corner of the tile in place about 1/4 inch back from the layout line. Place the edge of the tile roughly parallel to the layout line and set it in place.
Working with Uneven Edges
Tiles with irregular edges, such as saltillo and handmade pavers, are difficult to keep straight, and spacers aren't much help when it comes to aligning them.
To keep such tiles aligned, make your layout grids small โ a nine-tile (three-by-three) layout works well. Trowel adhesive one grid at a time, and set the tiles in place. Adjust the tiles until the appearance of the joints is consistent, and expect to make a few compromises.
Inserting a regular pattern of accent tiles into the corners of the pattern will also make the layout easier. The alternate figures in the pattern of the tile will distract the eye and add to the informality of the design. When grouting the tiles, make sure you remove all the surface grout so the irregular edges are visible.
Continuing the Pattern
Step 1: Lay First Section
Continue laying the tile in the first section, with the edges 1/4 inch off the layout lines. From time to time, step back and look over the section. The tile should not look like it's lined up perfectly; if it does, it will look staged or contrived.
Step 2: Tap Tiles
When you have finished laying a section, level the tile with a beater block made from plywood and carpet. The block should be wide enough to cover at least two tiles. Tap it with a rubber mallet. Because of irregularities, some tiles will rock. Take up the beater block and tap the high edge to even out the surface of those tiles.