Need validation on shower\bathroom concept

[Karel_c]

Hi all !

I've been thinking and researching for too long on how best to re-do my bathroom,so it's time for some questions...

Context:
I bought a 31 Excella 1972. I fully gutted it. Repaired frame, now installing subfloor. I'll change the floor plan to accommodate a back bunk room for our 3 daughters. Bathroom was in the back, now it will go on the side.

Disclaimer:
I am aware of all the complications that will arise because of that change (Venting pipes, plumbing, weight balance, walls that need to flex etc.). I did a lot of reading and it has been done and it can be done again. I am also aware that tiling a bathroom, or part of it, is complicated, and needs to be done properly with the right materials to allow for flexing.

My concept:
Sort of a wet bath...but not quite. Basically the whole floor of the bathroom would be a fiberglass pan, in an L shape to accommodate for the wheel well. On top of the fiberglass pan, slats of water-resistant wood such as teak, cedar or ipe. Those slat would be removable for cleaning/repairs. The toilet on top would be a composting (Nature's Head), so, easily removable even if on top of the wood mats. Cabinets on top of the wheel well.

Quick sketch:



I could have a custom shower pan made, but it would probably be very expensive, and since it doesn't need to be pretty (wood will cover it), I could probably do it myself. I have a bit of experience with fiberglass, even though it's been a while.

This is what I was thinking of for the pan:


You can see that I would have to find a way to have a sloped surface towards a drain, maybe by just sanding plywood and give it a slope with a belt sander and some 60 grit. To that sloped surface, I would attach 1/4 plywood boards all around so my fiberglass can go up against it to create a ledge. This would give me an L shape box that would be my "mold". I say "mold", because I would just fiberglass over it, and leave the plywood for support. Then paint the fiberglass with some sort special paint for baths and showers. I wouldn't think the weight addition of the extra plywood would be a problem, unless someone with more knowledge could chime in ?

This would be the cross-section of the assembly may look like:


I was thinking of using Kerdi-Board for the walls that would be tiled, overlapping over the fiberglass and preventing water seepage. The other walls covering would be some sort of waterproof sheet like shower walls.


I will have to build this bathroom as a "box" to allow flexing like others have done, so I'll find a way to attach the walls when I'm at that point. Sealer will be used everywhere necessary.

For the moment I would love to hear you thoughts on the concept.

Thank you !

[YippieKiYa]

My initial thought is that I’m jealous of your drawing skills...

Regarding the pan, have you considered stainless? Goes with the aluminum theme, and any good commercial kitchen stainless shop could build one for you to your unique specs. The design is essentially flat squares, so costs would not be as high as curved shapes with rounded lips. Heavier than fiberglass, but easily welded into what you need and the weight is right over the axles. They could form a lip around the edge to carry the tile, yet go a few inches up the back to shed water, too. Make it just like your plan with the pan floor welded to full-height sides in such a way as they carry the weight above to the subfloor. The base of the pan would be angled to the drain. Before you install it, flip it over and fill with structural foam to carry weight so you can use a lighter gauge of steel; trim flush. Beats sanding tapers into plywood. Won’t have to worry about a teak plank deck marring it, either.

[Karel_c]

Thank you for your response I haven't sketched in a while, I used to be a little bit better when I had my design classes. The kids were drawing this morning and I tagged along so I could put my ideas on paper.

I did think about stainless, and although it's probably the quickest method, I would expect at least 1000$ for fabricating just the pan. I also thought about the foam, but figured it would crumble to dust over time ? I'll still keep the idea and try to get a quote.

I also found that you could buy pre-sloped keri-boards specially designed for shower floors, but it seemed rather expensive of a product, and difficult to get here in Canada.

I'm still working on the design, thinking about pre-building the complete bathroom around the pan, then fiberglassing the floor, going up a few inches on the wall and maybe the wheel well. My goal is to not make the thing permanent. If I have a problem some day, I could unscrew the "box" from the wall, unscrew the window frame, and drain pipe, and then the whole bathroom could be moved a few feet to access whatever need to be accessed around the wheel well or window.

[DBinSD]

As a custom home builder for 18 years I think your idea is innovative.

I would have concern for the cabinets (moisture) and the removable flooring being an area to harbor moisture (mold etc.).

You could do without the removable flooring even though it looks "cool".

The "pan" idea would serve you well installed properly. The main issue left is the total moisture around/ on the cabinets IMO.

[Karel_c]

Originally Posted by Karel_c

If I have a problem some day, I could unscrew the "box" from the wall, unscrew the window frame, and drain pipe, and then the whole bathroom could be moved a few feet to access whatever need to be accessed around the wheel well or window.

The more I think about that, the more it seems complicated with the sink and other cabinets surrounding...

I think I'll focus on a bathroom that won't leak

[Karel_c]

Originally Posted by DBinSD

As a custom home builder for 18 years I think your idea is innovative.

I would have concern for the cabinets (moisture) and the removable flooring being an area to harbor moisture (mold etc.).

You could do without the removable flooring even though it looks "cool".

The "pan" idea would serve you well installed properly. The main issue left is the total moisture around/ on the cabinets IMO.

Thanks, you are right about the moisture around cabinets. I didn't provide details for that, but I was thinking of using some kind of composite material.

Also, I like the idea of the box mostly for the fact that it's a little bit more isolated from the shell when it'll flex. But I'll probably end up securing the bottom, and anchoring the top of the hallway walls. The rest of the box will allow for movement....I think.

As for the wooden floor, I'm pretty sure the right wood will not harbor mold. It has been done, I'm not the one to come up with the idea. I would give it a good pressure wash every time we empty the compost toilet and I think it'll be good.

Thoughts ?

[DBinSD]

I understand it HAS been done however, It is introducing more maintenance. A simple pan material would be water proof, aesthetic and easy to clean rather than have to remove to get the pan clean.

A composite box will probably work. All composites are subject to moisture intrusion from the cut edges as well, take precautions there. Make sure the securing penetrations are properly sealed as well. SikaFlex sealant is top notch by the way !

[YippieKiYa]

True, the stainless wouldn’t be cheap, but it would come together more quickly.

I’ve seen the prefab tapered boards, and they’re definitely slick. I’ve bet seen them used for a trailer, and they’re usually under a rubber membrane under masonry and tile. Could be made to work under fiberglass laid up in place.

Your idea of a “movable” bath is fascinating, but I’m not sure of the value vs. the complexity.

How were you planning on building the cabinets to deal with the moisture?

[Karel_c]

Hofman does it all the time. I'm trying to emulate his process. He gives just enough info on the process that you toy with the idea of DIY

[dbj216]

Hello from Colorado: You have a big project going with lots of innovative ideas for your new center bath.

Our 86 Limited has a center bath with shower. Many, many Airstreams have this arrangement. The shower stall is over the wheel well as well as the bath vanity. The toilet is inside the frame rail allowing for good placement of the black tank, which is right next to the gray tank. The shower pan is molded ABS plastic. I think Airstream sells replacement molded shower pans that might work in your design.

I'd worry about a "composting" toilet for a large family like yours. Composting is a nice word. Composting takes time. I fear you will be emptying the toilet frequently. Many campgrounds frown on emptying toilets in their toilets because of the mess. Make sure you research this thing carefully and talk to others where five people are using one. I bet you can buy a flush toilet, and a black tank with drains and vent for about the same money as a composting job.

David

[Karel_c]

David,

Thank you for your input.

Far from me the idea of trying to re-invent the wheel, I am mostly trying to gather the good ideas that are around. Sometimes it's just pictures, without explanation on how it was done. So I have to kind of retro-engineer to make it work, as it should.

I'll try to keep it simple...no promises

About the composting toilets.
I have searched intensively on the subject. An my conclusions are that:

- It does take out one big, disgusting task of having to empty a black tank.
- From what I gathered, what you get in the end in the Nature's head (or similar) bucket, is compost. It isn't supposed to smell, can be thrown in a regular garbage, or used as compost for plants.
- As for the pee, you are right that it would fill up quick with a family and that's why I'm thinking about having it connected to my tank so it can drain with grey water.

This guy replaced his toilet with a composting one in his airstream and it drains in his "black" tank. (maybe a member of this forum ?)

https://www.youtube.com/watch?v=8zZtozakkB8

I just don't understand why people frown upon composting toilets. But then again, I don't have one yet, so I can only rely on those who have one, and most say they'd never go back to a black tank....

That being said, I'll try to plan for the possibility of replacing the toilet with a classic system if I ever wish to switch back, or for a future owner.

[skyguyscott]

Have you considered Coosa Board, a waterproof composite as strong as plywood but 1/3 the weight.

It's not cheap, but likely cheaper, lighter and far easier to work with than stainless and could be a good alternative for this application, and no need to glass, unless you want to.

[skyguyscott]

Sorry, Coosa Board is 2/3 the weight of plywood, It is 1/3 lighter.

[Karel_c]

Originally Posted by YippieKiYa

How were you planning on building the cabinets to deal with the moisture?

I was thinking of a composite material like Corian or something cheaper. Still thinking about it. It will be small so maybe Corian would be in the budget.

[Karel_c]

Originally Posted by skyguyscott

Have you considered Coosa Board, a waterproof composite as strong as plywood but 1/3 the weight.

It's not cheap, but likely cheaper, lighter and far easier to work with than stainless and could be a good alternative for this application, and no need to glass, unless you want to.

I will check for prices, but usually getting stuff here in Canada, especially sheet goods, is always expensive cumbersome

It seems it can be joined with resin, so that's good. The weight is also very interesting, if we check the Nautical 15, it's 61% lighter. That would be really neat. I wonder if it can be shaped easily with a buffer for a taper...

I'll investigate
Thanks

[Isuzusweet]

Just my 2 cents

I don't like tile, it's very heavy and difficult to install in a machine that has been described as a rolling earthquake. Yes, tile is used in motorhomes, but they have a far more sophisticated suspension system. I would stay away from tile if I were you, as it will possibly end up being your nightmare.

How about these panels below? Cheap, relatively light, easy to install and completely waterproof/mold proof.

https://www.homedepot.com/p/4-ft-x-8...9600/100389836

or

http://www.lustrefx.com.au/products/multipanel

2) Coosa is completely awesome! I replaced the last 8' and first 8' of my sub-floor with Coosa board, and have been singing its praises ever since. I would take thin Coosa board, say 3/8" or 1/2" and using Premium Pro assemble the Coosa into the shape of the pan you desire. I would then fibreglass it to help it maintain shape, add strength, and seal it completely. Then with the FRP panels and Coosa, you would have a mold free, easily cleaned, waterproof bathroom.

If using wood to make cabinets, may I suggest a pine face frame with 1/2" Baltic birch sheet goods for the rest of the cabinet. I would use Western red cedar for the wood slates as teak and Ipe are bloody hard to work with and very very heavy.

You could line the pan with 1/4" Corian, but you can only get 1/4" in white, and it would take a skilled fabricator to do it well, but if you fabricate the pan and take it into a solid surface fabricator, they should be able to do it for you. You may also be able to use the Lustre panelling above to line it and your bathroom walls.

Cheers
Sidekick Tony

[Karel_c]

Originally Posted by Isuzusweet

Just my 2 cents

How about these panels below? Cheap, relatively light, easy to install and completely waterproof/mold proof.

https://www.homedepot.com/p/4-ft-x-8...9600/100389836


Cheers
Sidekick Tony

Yes, I've seen those mentioned before. Yes, they are cheap, and look cheap, sorry

I have yet to find a way to buy coosa board in Canada...if someone in Canada has bought some and has a source ?

You are right about the red cedar, it's an awesome wood, and less expensive than Teak.

As for the tiles....well, there are some ways to make it work. Every time I read a thread about tiling, it's mostly advised against. There's plenty of bad ways to do it, but when a guy like Hofman does it, I would think it's made to last. And that's what I'm aiming at.

By the way have you seen this:
http://flextile.com

It seems a bit sketchy, but it may be a really good solution.

[Isuzusweet]

Originally Posted by Karel_c

Yes, I've seen those mentioned before. Yes, they are cheap, and look cheap, sorry

I have yet to find a way to buy coosa board in Canada...if someone in Canada has bought some and has a source ?

You are right about the red cedar, it's an awesome wood, and less expensive than Teak.

As for the tiles....well, there are some ways to make it work. Every time I read a thread about tiling, it's mostly advised against. There's plenty of bad ways to do it, but when a guy like Hofman does it, I would think it's made to last. And that's what I'm aiming at.

By the way have you seen this:
http://flextile.com

It seems a bit sketchy, but it may be a really good solution.

There is a distributor in Nova Scotia for Coosa, that send its products to marinas across eastern Canada. I got mine ordered into Richardson marine in Meaford Ontario.

As for tile, again you need to reconsider what is design and what is functional. If you were to park your trailer year-round and never move it, knock your socks off and go for it. If you want to travel in it, don't use tile; it's a trailer, not a room in your house. The product link you sent me is meant for a motorhome, not a trailer. You have weight to consider, with a motorhome it is less of a consideration; plus your suspension is crap compared to a Class A.

Cheers
Tony

[Klatawa]

We have a '65 Tradewind that we changed from rear to mid bath. Very similar to your design, except we put a partial wall between the shower and sink cabinet. The black tank is directly under the toilet, the gray under the shower, axles between. We love this layout, even though the shower is small, it works great. We have an exhaust fan in the shower stall to remove moisture. The shower pan is raised for plumbing and built from Tennessee cedar then fiberglass. Put slope in pan by sanding.

[Karel_c]

Originally Posted by Klatawa

We have a '65 Tradewind that we changed from rear to mid bath. Very similar to your design, except we put a partial wall between the shower and sink cabinet. The black tank is directly under the toilet, the gray under the shower, axles between. We love this layout, even though the shower is small, it works great. We have an exhaust fan in the shower stall to remove moisture. The shower pan is raised for plumbing and built from Tennessee cedar then fiberglass. Put slope in pan by sanding.

Dave (or Debbie),

thank you for your input. It's a good idea to install a fan for sure, and in fact, I already have one in my cart for my next VTS order. Went to see your pictures, very nice ! I really like the color of the cedar.

I found that my nearest Lowes carry the Schluter shower tray and it's 120$ Cad. Reasonable amount if we consider I don't have to buy a belt sander and won't have to put a slope manually. I think I'm gonna go with that.

What I would like to do is affix a border to that Schluter shower tray and then get a quote to thermoform an acrylic sheet over it.

That would allow me to skip the fiberglassing process, would keep the weight down, and I could use a regular drain instead of their 130$ special drain.