DIY Network

Custom Shower Base and Floor Prep A perfect tiling job starts with a perfect surface. From "Bathroom Renovations" episode DBTR-502

Andy and JP’s new bathroom will have plenty of tile, including a tiled, custom shower base and a matching tile floor. Amy Matthews shows them how to pour a concrete base for the shower and prepare the floor so they can tile in style.

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Materials:

Shower Pan Installation: concrete ceramic floor mix bucket drill with paddle bit safety glasses dust mask rubber membrane hammer large-head nails utllity knife shower drain 2-foot level marker tape trowel

Subfloor Prep: duct tape self-leveling compound drill with paddle bit safety glasses dust mask cement board cement board screws impact driver

Custom Concrete Shower Pan

• If needed, use 2x4 lumber to frame in the "box" that will serve as the form for the concrete pour. Check local building codes for the correct concrete depth and the required size and thickness for the rubber membrane. The shower in this project will be flush with the side of the whirlpool bath, so the frame needed to extend under the tub overhang.

  Note: Amy had a professional plumber rough in the shower drain before starting the concrete installation.
  

  	Figure A
  	Figure B
  	Figure C
  	Figure D

• Spread out the rubber membrane in the space and spread it over the bottom of the form so that it overlaps the form (figure A). Make sure there’s enough material on each side of the form to extend up the wall to the correct height.
  
  
• Starting in one corner, flatten the membrane against the bottom of the space and push it tight against the bottom of the form board. Attach the membrane to the studs with large-head nails at least 8" from the bottom of the form (figure B). Except for the drain hole, the membrane should not be penetrated any lower than 8" up the wall to keep it completely waterproof. (Local building codes may have different requirements.)

• Carefully cut out the drain hole with a utility knife, making sure not to cut the hole too large. If any water ever gets through the concrete, the membrane will funnel it down the drain.

• Attach the drain plate by tightening the bolts with a socket wrench (figure C).

• Screw in the drain to a height of 1-1/4" to leave room for the concrete. Cover the chrome drain with tape to protect it during the concrete pour.

• Pour concrete mix into a bucket until it’s about one-third full. Mix in water and more concrete mix, following the manufacturer’s instructions, until the result is the consistency of a milkshake. Andy and JP used a spade-handle drill, which worked like a giant hand mixer. Concrete comes in different "recipes;" the sandy mix Amy chose for this project will dry to a very smooth surface.

  Safety Alert: Always wear a dust mask and eye protection when mixing concrete. Also, be sure to use caution when using a spade-handle drill or any power tools.

• Pour the concrete and spread it out with a trowel (figure D). The height of the concrete should gently slope from 2-1/2" around the outside of the form to 1-1/4" near the drain. When working with the wet concrete, strike it gently with the flat side of the trowel to help bring the moisture to the surface and smooth out the concrete.

• Allow the concrete to cure according to the manufacturer’s instructions before tiling.

Prepare Subfloor for Tiling

Note: An old or uneven floor – or one that needed patching to fix water damage, like this one – requires leveling before tile work can begin.

	Figure E
	Figure F

• Cover the seams around the edges of any plywood patches in the floor with duct tape. This will keep the leveling compound from dribbling through the seams to.

• Flip over the bucket of leveling compound to get the sand off the bottom. Roll the bucket on its side for 60 seconds to mix the compound, then finish off the mixing process by using a drill with a paddle bit (figure E).

• Pour the leveling compound onto the low areas in the floor and allow it to level itself (figure F).

• Once the leveling compound has dried according to the manufacturer’s instructions, install cement board over the subfloor. Secure the cement board with special cement board screws, not drywall screws.

  Safety Alert: Always wear a dust mask and safety glasses when cutting or driving screws through cement board.