Rubber Membrane Shower Pan Installation

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. 

regards   Chris 

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

Question from Jim Blog reader

I came across your responses to questions re: waterproofing and I appreciate your response as I am about to do a demo of a walk in shower. I will be taking it down to the studs as I am sure it has regular sheet rock and not hardieback as mold keeps coming through the grout. it is tiles floor, ceiling and walls.

My question is: I am removing all walls and tile and installing hardiebacker. I will be scraping tiles off the floor/pan and assume it is a poured concrete pad as the shower is a customer size - pretty long. After I scrape the tiles off the floor/pan and before I reinstall new tiles, will I have to do anything to that pan such as re-waterproof or perhaps even do a whole new pan? If I do, I will probably have to hire a professional as I am not confident that I can pour a new floor/pan. And I am afraid once I start demo, if I have to have a new pan installed, I will be waiting to find a professional to do it and that puts the shower out of commission for a long time. What are your thoughts and/or suggestions? Nothing has been started at this point.

RESPONSE

Jim

if you remove the tiles from the concrete pan carefully without cracking or gouging chunks of the concrete there is no reason you cant install new tile on it without removing it. If its a little rough or some thin set is left on the concrete you can just skim coat it smooth with thin set then let it dry a day  before you install new tile. There is no reason to remove the concrete and redo the pan if it is not leaking. Another options is to install your new tile on top of the existing tile floor just treat the existing tile with concrete bonding additive so the thin set will adhere good to the old tile lay your new  tile on top of the old tile . As for your drain  remove the drain grate screws and drain grate lay your tile so as the drain grate will sit flat on top of new tile(tile is laid just 1/4  inch inside of drain edge leaving screw holes clear to reinstall grate screws) get longer drain grate screws and screw grate flat on top of dry grouted finished tile.