DIY Network

Concrete Basement Shower Pan Create a built-to-code base for a new basement shower. From "Bathroom Renovations" episode DBTR-511

With the drain roughed in, Amy Matthews helps Andy fabricate a concrete shower base using a shower pan liner kit.

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This beautiful shower base starts with the strength of concrete.

Materials:

shower pan liner kit
utility knife
mastic
caulk gun
marker
nails
hammer
2x6 lumber
socket wrench
drain assembly

Concrete Basement Shower Pan

Note: Building codes have different requirements for shower pans. Make sure to check and follow local codes when fabricating a new pan.

• Make sure the area for the new shower pan is free of debris before getting started.

• Amy and Andy used a shower pan liner kit for this installation. The liner in this kit was made of rubberized asphalt laminated to a reinforcement fabric. The 5' by 6' membrane fits showers up to 4' by 5'.

• Spread out and center the liner across the floor of the shower space and up each wall. The liner should go at least 6" up the wall on all sides. When the liner is centered, make a small hole in the liner with a utility knife to mark the center of the drain.
  

  	Figure A
  	Figure B
  	Figure C
  	Figure D

• Remove the liner from the shower area to prep the drain.

• Remove the drain grill and set aside. Seal the drain base to the concrete with a bead of mastic (Figure A).

• The kit included a sticky piece of 12" x 12" detail tape. Cover the drain with this material – sticky side down – and press into place over the drain (figure B). Cut an X in the detail tape over the center of the opening and fold the tape down, conforming it to the shape of the inside of the drain.

• Lay out the membrane in the shower space, fabric side down. Find the hole for the drain location and center it over the drain opening.

• With the reference hole centered over the drain, center the drain template (provided with the kit) over the drain. Trace the template to mark the outline for the drain (figure C).

• Carefully score the backing of the membrane, taking care not to cut through to the rubber.

• Position the membrane in the shower area, lining up the cutout on the drain.

• Smooth the liner over the bottom of the shower, pressing it into the corners and smoothing it up the walls. Nail the sides to the studs with large-head nails such as roofing nails. Fold the membrane at the corners (like making hospital corners with bedsheets) so that they lay flat before nailing into the corners.

  Note: Check local codes for the acceptable height for nailing through the membrame.

• Screw a piece of 2x6 lumber to the studs to create a form for the shower threshold.

• Carefully cut out the opening for the drain, making sure not to cut the hole too big.

• Feel through the membrane around the drain to find the holes for the clamping ring screws. Use a utility knife to make small openings at those points and screw in the clamping ring screws with a socket wrench (figure D). Set the clamping ring in place and screw it down tight to the drain. This will form a water-tight seal around the membrane.

• Draw a level line all the way around the membrane, 3" up from the floor. This is the fill line for the concrete at the wall.

• Screw the top part of the drain into the clamping ring, leaving about 1-1/2" of clearance between the bottom of the drain and the membrane for the concrete. This will give the shower pan 1-1/2" of slope between the walls and the drain. Make sure to cover the drain opening with painter's tape to protect it.

  Note: Check building codes for the correct shower drain slope for your size of shower.

• Use a drill with a paddle bit to mix concrete according to the manufacturer's instructions. The concrete should be about the thickness of a milkshake.

  Safety Alert: Always wear safety glasses and a dust mask when mixing concrete or any masonry adhesive. Use caution when working with a drill or any other power tools, especially tools powerful enough to mix the concrete.

• Pour concrete into the shower space, working it into all of the corners and spreading it with a large mason's trowel. Tamp down the concrete with the flat side of the trowel to bring moisture to the surface for a smoother finish, sloping the surface of the concrete "downhill" toward the drain.

• Allow the concrete to dry and cure according to the manufacturer's instructions. Amy and Andy came back later to build a form and pour a threshold for the shower.
  
  
  

  RESOURCES :
  Shower Pan Liner Kit
  Protecto Wrap
  Website: www.protectowrap.com
  

  ALSO IN THIS EPISODE:
  	Shower Drain Rough-In
  	Concrete Basement Shower Pan
  	Basement Bathroom Floor Tile
  	Five-Way Wall Tile
  	Recessed Cabinets