Q I laid down ceramic tile over our exposed aggregate outdoor patio. These lasted about five years. Now, many of these tiles are lifting and some sound hollow underneath. My question is: What process would you recommend to prepare the surface to create a smooth finish before reapplying tiles?
A The de-lamination of tile is due to environmental stresses such as moisture exposure and freezing. For exterior ceramic tile setting the correct process should have been as follows:
1. Clean the concrete with my Shell Busey Home Cleaning Formula.
2. Apply an acrylic concrete adhesive over the entire exposed aggregate surface (not in direct sun.)
3. Next, apply a thin coat of bonded topping mix or top-n-bond to level the surface.
4. I recommend the Schluter-DITRA system for exterior tile applications. More information is available by going to Ames Tile and Stone's website at www.amestile.com.
5. Set tiles into the exterior thin set over the Schluter-DITRA System.
6. Grout with epoxy exterior grout. In preparation: Consider renting a tile removal tool to save tiles for re-setting and chip off as much of the original thin set as possible.