How to Paint a Faux Limestone Finish
Paint subtle limestone-look blocks on a wall, using latex paints and tinting colors.
The homeowner chose Mexican limestone tiles for this project. The tiles come in sheets with a fiberglass meshing on the back. For this project, we chose to add some colored recycled glass tiles to the limestone tiles.
Choose a design. An architect drew out a specific design for us to follow (Image 2).
Because the plywood has ridges and seams, a backer board had to be put up first before applying the thinset, and with plywood being on the wall, they only needed 1/4" backer board. Backer board can be cut with a utility knife but needs to be scored first using a straight edge as a guide. After you score the board, you just snap it like drywall.
Note: Backer board is made from cement and won't rot or swell when exposed to moisture. You can make fine cuts in the backer board with a jigsaw.
Before you put the backboard on the wall, apply a bead of construction adhesive. This helps create a positive bond so there is no void that would cause a flex. Push the backer board gently and easily into the adhesive.
Screw the board to the wall using special screws that have ridges under the head. These cause the screws to automatically countersink into the backer board.
Be aware of pipes in the wall. Find their location before you start.
To mix the thin-set mortar for applying the tiles, put approximately 1" of water in a bucket, and add powder and mix with a paddle mixer until you get the right consistency. The thinset has to set up for about 10 minutes (slaking) before you can use it.
Mortar can get dusty, so wear a dust mask. Also, any cement can irritate your hands, so be sure and wear gloves.
Lay some thinset on a notched trowel and spread it evenly on the wall and then lay your first piece of tile in place.
Once you have the first section of tiles in place, you can cut tiles out if you are going to add colored tiles. Each of the colored tiles has to be buttered (meaning a thin layer of mortar applied to the back of the tile) and then set the tile in place.
Any excess thinset should be wiped off with a sponge before it dries.
Use a wet saw to cut the end tiles. Use an even pressure on both sides as you run it through.
The tile has to set up for 24 hours before you apply the grout.