Converting a tub shower into a roll in shower can be rather difficult but with a little know-how and determination most diyers should have no problem installing a barrier free shower. There are a few options available from simply installing a fibreglass shower insert to laying a mortar bed complete with waterproof membrane and titled shower floor and walls.
Note: This article is intended as a guide and not a complete how-to. We’ve provided links to our research sources for you to look into further. Be sure to research all local building codes and obtain a permit if necessary. If you need to get this right the first time, then hiring a professional might be a good idea. And also make sure to use common sense and be safe!
Getting Started
Remove the tub and existing fixtures. Once you get the tub out you’ll see just what the framing is like behind the walls and if there is any water damage that needs to be repaired in the framing or subfloor.
Rough-in the plumbing. You’ll need to make sure the shower valves are within reach of a person seated in a wheelchair from outside the shower. This allows them to start the shower to get it to the correct temperature before getting in.
Install some plywood for a subfloor or repair the existing subfloor if needed. The drain flange must generally be 2 inches below the rest of the bathroom floor. This will allow a slope of 1/4″ per foot over the entire shower floor. Moving the drain location to the center of the shower area rather than where it was for the tub can help reduce the depth requirement for the drain. If that’s not possible then you can build a ‘hump’ from the mortar bed to raise the shower floor surface to allow the correct amount of slope to the drain.
Mortar Preslope
It’s recommended by The Tile Counsel of America & ANSI standards to create a slope under the waterproof membrane. This allows the moisture that penetrates the tile grout and mortar bed to flow towards the drain flange and through the weep holes. This article has great photos an instructions of the full process.
Shower Pan Liner
Next lay down the PVC membrane to make the shower floor waterproof. Tile grout and the mortar bed underneath are both porus and during normal use of the shower will slowly let water seep through. This membrane provides a barrier to stop the water and guide it to the drain before it can do any damage. Each side of the membrane should extend a minimum of 9 inches up each wall. Fold the corners and tack the membrane to the framing with staples or nails, just 1/2 inch below the top of the membrane.
Feel for the bolts in the drain flange and then start to cut away the material over the drain. Slowly make the hole bigger to expose just the drain hole, the three bolts, and the weep holes. Again, Ontario Tile has some good photos of this part of the install. Be sure to check out the photo of the unobstructed weep hole.
Apply sealant between the liner and the bottom flange only. Do not apply sealant to the top half of the flange or you risk blocking the weep holes. Bolt down the top part of the flange and get ready to put the cement board up for the walls. When installing the cement board make sure to leave a decent gap to prevent wicking of moisture up the wall.
Sloped Mortar Bed
Once you have the boards on it’s time to lay the sloped mortar bed. See this article for a great description of how to lay a mortar bed. After the mortar has set apply the tiles with thinset. Wait 24 hours for the thinset to cure then apply the grout to between the tiles.
Other Approaches
A premade shower tray is an alternative to laying a mortar bed. They come in a number of premade sizes and allow you to get the proper slope without the hassle of mixing mud and smoothing it out and such. Schleter Kurdi is one of the popular ones. Their install handbook provides a very good description of the install process.
Preformed Shower Pan or Liner
One piece shower pans are a good choice as well since they save the time of laying a mortar bed and tiling. If you are concerned about bacteria and mold growth then you’ll be glad to know that solid acrylic shower pans are non-porus (check your model before buying) so they resist microbial growth. Some shower inserts also feature full shower walls as well. Reducing the install to preparing the sub-floor and plumbing. Laying some sand or foam for support of the pan (if needed) and then sealing it in place with an epoxy.
That wraps up converting your tub to roll in shower conversion. Things to keep in mind: put the valves within reach of the person using the shower from outside the shower; and make sure you are able to deal with any water that may flow out of the shower area. Have the person test out the shower to see if curtain control is a problem or if water floods out of the shower unit along the floor, StayDry products can help with these situations.
The Collapsible Shower Water Dam stops water flowing out of your shower unit onto the floor. It’s made of durable foam rubber and compresses to only 1/4 inch with gentle pressure. The Deluxe Shower Curtain Kit features a shower curtain that seals to the sides of your barrier free shower unit. This stops the shower curtain from blowing around allowing spray to get all over your shower floor. Lastly our Extra Long Shower Rings are available in sizes from 4.5 inches to 8.5 inches. They allow you to lower your shower curtain so the bottom edge is caught just behind the Collapsible Water Dam.
References & Resources
How to Install a Shower Pan Liner – by John Bridge
roll-in shower? – discussion thread from JohnBridge.com
Goodbye to Water Worries – Install a Shower Pan & Liner – by Matt Weber
Install a Solid Surface Shower Pan – by Milton Lemberg
