Not all damage on a slate wall fountain is reparable. A homeowner should assess the condition of the fountain fully in order to save on costs, time and effort. But if the damage is just on a single slate or two, then repairing it is the best route for the homeowner.
Determine if the Stones are Stacked or Tiled
There are two ways to build a slate wall fountain. Either the slates are stacked, much like bricks, or tiled like regular ceramic wall tiles. How you address the issues will depend largely on the orientation of the tiles.
With stacked slates, you have to purchase a replacement slate that has the same thickness as that of the damaged slate. The thickness of the new slate must fit in the hole that the old slate will leave behind. Length can be cut easily with a diamond wet saw. Differences in slate color are not much of an issue since only a thin part of the slate is displayed.
For tiled slates, selection of a replacement is much challenging. You have to find a stone that matches the old slates in terms of color, smoothness, thickness and size. If not, the newly installed slate will look off with the rest of the tiles.
Pry Out or Chip Off
When removing a stacked or tiled slate on a fountain wall, you have to remove the grout first around the damaged tile. Either you scrape it with a wire, formed into a melon baller-like scraper, or chisel it with a thin chisel and a light hammer. Next, pry the damaged slate out with pliers, if it is from a stack, or if it is tiled, chip it off by chiseling the slate tile on the center until it crumbles.
Install the Replacement
Use a thinset mortar as adhesive for the slate stone. Thinset mortar is perfect for use in a wall fountain because it can withstand moisture. Apply the mixed thinset on the slate tile. For stacked slates, position the replacement into the hole and wiggle it so that the mortar will stick onto the surface of nearby slates and onto the new slate. For tiled slates, apply thinset on the wall and at the back of the slate. Position the slate and space it out evenly.
Select grout that matches the color of your old grout. If you prefer, now is the best time to re-grout all areas of the slate fountain wall. You only have to scrape or chisel out the grout as mentioned above.
Prepare grout mix. Apply it using a rubber float angled in 45-degrees so that grout will reach all spaces. Wipe the excess grout to prevent grout hardening on the surface of the slate.
A sealer not only gives added gloss on the slate; it protects the slate from stains and organism growth. Use a natural stone sealer that is perfect for shower or bathroom tiles. Spray or brush the sealer on the slate with several coats.