Build my own cabin - DIY projects

How to Build a Waterproof Shower Bench

The following is a unique step-by-step method for adding a bench or seat to your shower that is simple, waterproof, extremely durable because it's made out of concrete.  After finding water damage under several shower benches constructed of wood and lined with waterproof membranes, I started making concrete shower benches and have never had a single issue.  I'll walk you through the steps of the concrete shower bench and you'll see it's pretty slick.

concrete shower bench construction

The concrete shower bench should be added after hardiebacker and waterproof membrane is painted on the walls.  Determine the size of your bench, in this case I created a bench 16" x 16" x 8", and cut some scrap plywood up to form a box. Brace the bottom of the form to keep it up tight against the wall when the concrete is poured in.  Add a few pieces of rebar or left over metal lathe if you have some kicking around.


Another picture of the concrete bench formed up.


Mix up a few bags of Quikrete high strength concrete which cost about $3.50/bag at Lowes.  Slope the top of the bench away from the wall about 1/4" so that water flows off the top of the bench into the shower and not against the wall.  Let the concrete dry at least 24hrs.


Pull the forms off and there you have the concrete shower bench.


Tape the joints and cover the shower bench with a coat of thinset.


Paint the seat with Redgard or Aquadefense waterproofing membrane, the same material used on the walls.  With the concrete shower seat you never have to worry about water damage.  It's solid concrete, and even if water migrates through the joints between the seat and wall it will follow the wall down to the shower pan and make its way to the drain the same way is would if the bench was not there.  The concrete shower bench provides a great surface to apply tile to as well which is nice. 

Step 1: Shower Demolition

Step 2: How to Replace a Shower Drain

Step 3: How to Make Shower Deck Mud

Step 4: How to Build a Shower Floor 1 (Curb and Pre-slope)

Step 5: How to Build a Shower Floor 2 (Liner, Drain, Final Slope)

Step 6: How to Install Shower Backerboard

Step 7: How to Build a Waterproof Shower Bench

Step 8: How to Tile Shower Floor

Step 9: How to Tile and Grout Shower Walls