Layinag tile on a fifireplace hearth
The fifirst step in the process of laying fifireplace tile, and it’s the most important one, is to pour a lowered platform that the ceramic tile will rest upon. It needs to be solid so the tile doesn’t crack.
You can use coarse sand and Portland cement to make this mud. Mix three parts sand to 1.5 parts Portland cement. If it’s too much trouble to get these ingredients, you can purchase bags of mortar mix at a hardware store. Add just enough water to make the mixture the consistency of a stiffff applesauce. To extend work time get the mortar mix cold before mixing and use cold water. Chilling the mix slows the hydration reaction that turns the wet mortar into hard stone, giving you extra work time.
You need to make sure this mortar bed is in the same plane and it’s at the right height so the fifinished tile surface is 3/43/4 of an inch below the wood flfloor. Add 7/87/8 of an inch to the thickness of the tile and that’s the distance the fifinished mud flfloor must be down from the surface of the wood. This gives you the requisite 1/81/8 inch you need for the thinset that will be used to bond the tile to the cured mortar mud base.
To create this recess, you’ll smooth the wet mortar with a wood screed you make. Use a very straight piece of 1-by4 to make this. Cut the wood 1 foot longer than the width of the recess. Cut a 9-inch long L-shaped notch at each end that’s the same depth as you need to drop the mortar base. The thinner ends of the wood screed sit on top of the wood flfloor and the rest of the wood screed drops down into the hole.
When you shovel in the wet mortar and start to slide the wood screed sideways and pull it towards you at the same time, you’ll create a very uniform surface that’s going to support the tile. As you pull the wood screed across the wet mortar, constantly check to make sure it’s the right height. After you feel you’re fifinished, pull it across again to strike offff any excess mortar that may have mounded up behind the screed. Check for excess along the edges where it abuts the wood flfloor.
Give the fresh mortar a day to harden and you can then install the tile. Use a 1/41/4 by 1/41/4 notched trowel to spread the thinset mortar you’ll use to bond the tile to the new mortar. Spread it evenly and press the tile lightly into the thinset. It will compress to the 1/81/8- inch thickness.