How to Tile a Floor Using an Underlayment Membrane

Floor tile are commonly made of either ceramic or porcelain:

  • Ceramic Tile: Long considered the standard in floor tile, ceramic is made from fired clay with a glaze coating. While often less expensive than porcelain, ceramic tile is not as durable.
  • Porcelain Tile: This tile is composed of sand which is fired at high temperature and pressure. Since it isn’t porous, porcelain tile is more water resistant and harder than ceramic, but it is harder to cut.

When installing a tile floor, a layer of cement backer board is usually put down over a plywood subfloor to provide a firm, stable surface. A waterproof underlayment membrane like Ditra from Schluter Systems can be substituted for backer board. Made of lightweight polyethylene, the membrane is only 1/8” thick and can be cut easily with a utility knife.

When using the membrane:

  1. Cut the membrane to size.
  2. Apply a layer of thin-set adhesive fortified with latex to the subfloor.
  3. Roll the membrane out, and position it in place.
  4. Apply a bed of thin-set without latex additive, and set the tile in it.

Tiles can be cut using a hand operated “score and snap” cutter or a motorized wet saw.

After the tiles have set, apply grout to the joints using a rubber float. Grout is available in a variety of colors, but darker grout stains less. Stainproof grout is also available.

Once the grout has set, apply a grout sealer to the joints to prevent stains from occurring. If grout has already become stained, a grout stain pen can be used to stain the grout a uniform color.