How to Waterproof a Tile Deck

Waterproofing a Plywood Subfloor

• 1
  The waterproof membrane should continue up the wall about 12 inches where the deck meets the wall.tile pattern image by sumos from Fotolia.com
  
  Install a bonded waterproof membrane on top of the mortar bed to prevent moisture from entering the system.
  
  
• 2). Install a drainage layer over the waterproof membrane. Use crushed stone or crushed tile topped with a fabric filter. If the floor includes a drain, crushed stone or tile should be placed over the weep hole to keep the holes open for drainage.
  
  
• 3). Set your tile according to your preplanned pattern. Grout the tile over the 1/4-inch spaces between tiles. Use Aqua Mix to waterproof the tiles. Allow the tiles to cure 24 to 36 hours before allowing heavy traffic.
  
  

Waterproofing Existing Concrete Slabs

• 1
  Laying mortar requires a spreading tool.Iron and mortar. image by iChip from Fotolia.com
  
  Mix mortar with water only---no additives. Lay a thin-set over the concrete.
  
  
• 2
  Ditra is a waterproof membrane that comes in large rolls for construction projects.cells 21 image by chrisharvey from Fotolia.com
  
  Roll out a sheet of Ditra to lay over the thin-set. The Ditra will bond to the slab with the thin-set mortar mix. Ditra will allow expansion and contraction of the subfloor without transferring movement to the tiles.
  
  
• 3). Lay strips of Kerdi membrane on every seam of the Ditra to prevent any moisture from seeping in. If the concrete is porous or cracked in places, add a primer before installing Ditra and Kerdi to increase the bond of the thin-set.
  
  
• 4
  Some people prefer about a 1/4-inch space between tiles for grouting.tiles image by charles taylor from Fotolia.com
  
  Set the tiles according to your design, then grout the 1/4-inch spaces between the tiles with mortar mix.
  
  
• 5). Apply a water-based sealer like Aqua Mix to the tiles with sponges 2 hours after grouting.
  
  

Waterproofing Preexisting Deck Tiles

• 1). Apply a water-based treatment such as Aqua Mix, which is recommended for marble, limestone, granite, slate, tile and grout, using a sponge, paint pad applicator or sprayer.
  
  
• 2). Reapply the sealer after 30 minutes if more coats are needed. Apply a few drops of water to the tiles. If the water soaks in, apply another coat.
  
  
• 3). Give the tiles 24 to 36 hours to cure before allowing heavy traffic. Note that this method will not work if the subfloor has not been properly waterproofed. It is not a stand-alone method and will not keep moisture from being trapped beneath.