Rubber Membrane Liner Do's and Don'ts
In the past we've written about copper pan vs rubber pan liner. This article focuses exclusively on the rubber pan installation itself. With step by step pictures of the rubber pan going in including the drain attachment you will see and understand the do's and don'ts associated with the correct install so you never have to worry about a leaky shower.
Always use a single solid membrane for your shower pan. It needs to be 2 feet wider and longer than your actual shower floor area. Example if your shower is 3 ft by 5 ft then you need a 5 ft by 7 ft solid rubber membrane. Your rubber membrane needs to go 1 ft up the wall nailed to your wall studs. NEVER nail below 8 inches from the floor. TO CLARIFY KEEP ALL NAILS 8 INCHES ABOVE FINISH FLOOR. Wrap rubber liner over curb and nail Only on outside of curb. NEVER NAIL ON INSIDE OF CURB . Fold corners inside studs when possible. The drain is a 3 piece set, The adjustable screw in drain attaches to the bolt down plate which creates the actual seal against the rubber membrane. The solid one piece membrane goes right over the bottom drain plate and is cut only with a small slit for the 4 mount bolts. The actual drain hole is not cut until the seal plate is bolted\screwed down. The pictures below clarify this process.
After the membrane is installed the Hardi board can be installed on the wall AGAIN NO NAILS BELOW THE 8 INCH MARK ALL NAILS NEED TO BE 8 INCHES ABOVE FINISH FLOOR as not to create a leak in the membrane. Hardi board can be nailed on top of the curb with generous amounts of caulk used under the Hardiboard to insure top of curb seal . Hardiboard on inside of curb is NEVER nailed and will be held in place by the concrete packed on shower floor to create slant to drain.
Rubber membranes installed correctly can always be counted on for decades of leak free shower use. They are by far the most dependable as well as the most economical options for shower floor dry installation. The highest quality option and the most affordable; can't do better than that!!
Follow the photos below for the step by step walk-through. Ask any questions below.
Rubber membrane nailed 1 ft up bare wall studs
Notice rubber membrane tucked into wall stud and nailed 12 inches up wall stud
Rubber membrane wraps over curb then nailed on outside of curb and
Hardi board on top with caulk under to seal
A closer look of membrane nailed up wall studs notice nails 12 inches high
Rubber membrane ready for top plate to screw down to create
watertight seal between drain plate and membrane
Top plate screws down in equal sequence to create watertight seal
Final tightening of seal plate om rubber membrane
Finish adjustable screw in drain ready for concrete slant to be packed
Another view of membrane wrapping over shower curb
Hardi board nailed on wall after membrane installation NEVER
nail below 8 inches from finish floor
Tops of curbs finished with Hardi board sealed underneath with caulk and nailed
Finished Hardi board installed after membrane installed. Notice Hardi board caulked
in corner to seal board