Lightweight Custom Shower Enclosure

[Dennis Putnam]

I am in the process of installing a customized shower in a special purpose trailer where weight is critical and space is both limited and odd shaped. I expect to have a custom shower pan made but beyond that I'm uncertain. Since no standard enclosure will work I need to build something myself. My thinking is to use the Kerdi system (walls are 5mm ply) but I don't know how much weight per foot the mortar will add. Even more important is what kind of lightweight finish surface I should use. I don't like plastic tile but I don't really know of an equivalent (weight-wise) alternative and I don't know if it is compatible with the Kerdi Membrane. Any suggestions would be greatly appreciated.

[Ellen Benkin]

I suggest you contact RV manufacturers. I think they would face the same constraints, especially with the smaller RVs.

[Lee Schierer]

Most RV's have showers that fit in small places and are light in weight. Do a search for rv shower enclosure and you will find numerous sources.

[Dennis Putnam]

Like I said this is a custom shape. No standard RV or any other type enclosure will work. I have to build it from scratch.

[Jamie Buxton]

Tile in a trailer doesn't sound good to me. The stuff is heavy, and it is brittle.

How 'bout fiberglass over wood? Folks build kayaks with thin wood strips, and cover it with a layer of fiberglass cloth and clear resin. If they do it right, the result is a waterproof boat that can take the stress of being in the ocean. It doesn't look bad, either -- the wood is visible through the fiberglass. Here's a pic -- http://www.oneoceankayaks.com/Gallpics/large/storm4pmlg.jpg

[Dennis Putnam]

Yep that is why I was thinking plastic tile but I don't know how well it would work with the Keri membrane. I have not worked with fiberglass so I don't know how to blend that at the bottom where the ply meets the pan to make it waterproof.

[Brian Elfert]

How about FRP sheets attached to plywood? This is what I have in my custom shower in my converted bus. The whole bathroom is covered in this stuff. It is used in showers all over the place. You just need to follow the directions carefully to make it water proof.

Custom means an RV type shower enclosure won't work. RV shower enclosures are cheap, cheap, cheap to keep the cost and weight down. They figure the average RV owner doesn't actually use their RV very much so cheap will hold up at least long enough to get past the warranty.

[Dennis Putnam]

Hmm. I hadn't thought of that. Probably wouldn't look that good but I'm interested in function more than esthetics. How would I seal he bottom where the FRP meets the pan? I can't have moisture getting in behind it. There is also a question of how to attach it to 5mm ply. I'm not sure liquid nails is sufficient.

[Brian Elfert]

There is special FRP adhesive that is troweled onto the wall that holds the FRP in place. It won't come off if you follow the directions. There are also special moldings that work with the FRP to keep it water tight. You have to follow the instructions to keep it water tight. See http://www.jensenbridge.com/files/FRP/FRP%20Installation%20Guide.pdf I would avoid the mechanical fasteners and just use the adhesive. The fasteners are a place where moisture could penetrate.

I used a shower pan with a lip around the edges. The FRP goes over the lip so water drains into the pan. I used FRP molding and caulk where the FRP meets the shower pan.

[Dennis Putnam]

Thanks, I'll look into that. I do worry about mold breeding in caulk. Even the anti-mold stuff seems to fail eventually.

[Brian Elfert]

All I know is they use FRP panels extensively in gym showers and commercial kitchens. My RV shower doesn't get used enough to worry about mold growth.

[Phil Thien]

How about having a kitchen supply bend-up some stainless?

[Jamie Buxton]

.. I have not worked with fiberglass so I don't know how to blend that at the bottom where the ply meets the pan to make it waterproof.

The people who make fiberglass and wood kayaks have this solved, so you don't have to invent it. They make waterproof boats, and the interior angles are far more complex than most shower stalls. Go read up on it before you dismiss it.

[Tom M King]

Multi layers of thin fiberglass cloth is easily formed into almost any shape you want. Laying up fiberglass is not hard, and I'd bet there are plenty of youtube videos even.

[Jamie Buxton]

[Sound of me slapping my forehead.] We have a boat-building forum here on SMC. Currently, the hottest thread on it describes building a wood+fiberglass canoe. http://www.sawmillcreek.org/showthread.php?233598-Scratch-Built-16-quot-Cedar-Strip-Canoe