How to Prepare a Subfloor for Terrazzo Tile
Before you can install floor tile, there must be a viable subfloor that the tiles can adhere to. Follow these step-by-step instructions to prepare a wood subfloor for tilework.
To keep cement off the floor surface, position tar paper on the floor past where the hearth will go and secure it with electrical tape.
Tape plastic sheeting on top of this to further protect floors.
Measure the hearth area carefully, then cut mesh 1/2" shorter than the desired length and depth of the hearth.
Screw nails in about 8" apart and about 1" away from the edge of the lath.
Fit the cement block to the pattern you’ve laid out on the floor with the lath and plastic.
Mark the back of the block where the cuts will take place. Use a circular saw with a masonry blade to actually make the cuts.
Place the blocks into position in front of the fireplace.
Mix concrete, then fill each block with concrete to about 3" deep. Push the concrete down so it will settle evenly.
After the concrete has dried, use a level to make sure the hearth is still straight.
Position the cap blocks on top of the hearth, then mark (Image 1) and cut the blocks to fit.
Add mortar to the top of the blocks before setting the cap blocks into place (Image 2). Stop to use a level often.
Spread mortar over the entire hearth, top and sides, then mix plaster and color pigments to the desired tint (Image 1).
Test the color by placing it on a sample board and letting it dry in the sun.
If the color is the desired tint after drying, use a trowel to smear the plaster onto the hearth surface (Image 2).
Create the look of bricks and mortar by using a tongue depressor to cut through red plaster and expose the gray concrete.
Shape some of the corners to give the "bricks" the look of being cut with a saw.
Dab a little gray and black cement onto the bricks to create an antiqued appearance and help the new hearth blend with the old fireplace.