How to Install Ceramic Tile Over Cork Flooring Underlayment

Using cork flooring underlayment is a great surface for ceramic tiles because of its insulating and soundproofing properties. While ceramic tile is usually laid over plywood or cement backer board, cork underlayment has become a viable alternative, especially because it is a natural product. As a ‘green’ material, cork is a great choice for underlayment. Using a natural, renewable resource such as cork flooring underlayment may be more expensive initially, but the long-term investment is worth the extra cost. It is not advisable to use cork in wet areas such as a bathroom, however.

Tools & Materials

  • Cork underlayment
  • Adhesive
  • Notched trowel
  • 100-pound roller
  • Chalk line
  • Ceramic tiles
  • Tile cutter
  • Thin-set mortar
  • Grout
  • Float
  • Sponge
  • Grout sealer

 

Step 1 - Prepare Floor Surface

To prepare for the cork flooring underlayment, remove existing floor if necessary. Sweep, vacuum, and wash floor as the floor must be free of dust and dirt particles for the cork adhesive to adhere properly. If the cork is not adhered, the ceramic tile will ultimately crack. Allow to dry at least 24 hours if washed. Level floor with thin-set mortar, correct all imperfections and sand once thin set has cured (24 hours). Be sure to even out any cracks or nail punctures to achieve as level a surface as possible. Sweep and vacuum all sanding dust from leveled floor to allow proper adhesion of underlayment.

Step 2 - Set Cork Underlayment

Assimilate cork flooring underlayment to area being floored for at least 48 hours. Measure length of the room, and cut a piece of rolled cork a little bit longer than measured length (about 1 inch longer). Roll just cut cork out onto floor, and cut to perfect length. Continue down the room, cutting each piece in place. Starting with the first piece, roll back half of the length, trowel the floor with adhesive, roll back into place and repeat for other half. Immediately roll the cork with 100-pound roller to fix in place. Continue down the line with the rest of the cork. Roll the cork with the 100-pound roller one more time, both directions. Use a hand roller along the edges to assure full adherence of cork. Allow adhesive to cure 24 hours.

Step 3 - Lay Ceramic Tile

Measure and mark the center of the cork flooring underlayment in the room in each direction; where the lines intersect is the center of the room. Check center marks for square using a builder’s square. Trowel enough thin-set mortar to lay the first 4 tiles (use spacers along each side of each tile at the mark (one at each quadrant of the ‘+’). It is critical that the first tiles are laid perfectly square, as the remaining tiles will follow the layout. Continue laying tiles, completing 1 quadrant at a time, and using spacers between each tile. After all whole tiles are laid, measure and cut all edge tiles. Lay edge tiles. Allow mortar to cure for at least 24 hours. Remove spacers. Grout tiles, using the grout float, push grout into spaces between tiles. Wipe additional grout off tiles with wet sponge. Allow grout to cure for 24 hours, and then seal grout. Caulk all joints where tiles meet walls or other obstructions to allow for expansion and contraction. Now you can enjoy your new ceramic floor with a comfortable cork flooring underlayment.