Building a wetbath

[VanKitten]

I have a very odd size and shape to build the bathroom.   Also, want to keep the weight down.

I have had this recommended to me... Kerdi system with pvc wall panels.   Built on a drywall build.   The Kerdi system comes with drain and curb too.

Anyone have any experience with Kerdi?

 

[TMG51]

I have a very odd size and shape to build the bathroom.   Also, want to keep the weight down.

I have had this recommended to me... Kerdi system with pvc wall panels.   Built on a drywall build.   The Kerdi system comes with drain and curb too.

Anyone have any experience with Kerdi?

I'm not familiar with the "kerdi system," but for some time now I've been envisioning my future shower stall build using PVC wall panels. PVC is not susceptible to moisture, doesn't rot, needs no paint, corners seal well and remain flexible...

I would not use drywall in a mobile build.

PVC sheeting is available special order from lumberyards. My plan for my next build is to make a shower stall out of such, with plywood backer if necessary.

 

[highdesertranger]

what TMG said^. especially the drywall. drywall is heavy. did I mention heavy. highdesertranger

 

[Gary68]

there are tons of kits
http://www.homedepot.com/b/Bath-Sho...l/Ntt-bathroom+kit?NCNI-5&Ns=P_REP_PRC_MODE|0

if you have the tub/pan you can cut the walls to fit

i have also seen rv bathroom for sale on craigslist and parting out motor homes

 

[VanKitten]

The wetbath will have to have a small step up inside. So 30x 28. On the 28 side...3" step up. Then I have 18 more inches. So really 30 x 46. I plan to put the toilet on the 18 inches...build a bench right in.

It looks like the Kerdi system goes to drywall. The only waterproofing system I saw for plywood requires and additional layer over the top

I worr.y that with all the movement...the pvc panels (which all have to be cut to fit around this odd shaped room) will not remain water tight....hence the need for making the walls behind it water proof.

 

[TMG51]

It looks like the Kerdi system goes to drywall.   The only waterproofing system I saw for plywood requires and additional layer over the top

I worr.y that with all the movement...the pvc panels (which all have to be cut to fit around this odd shaped room) will not remain water tight....hence the need for making the walls behind it water proof.

Drywall is far from water proof. The green stuff is advertised as water resistant, and spec'd for use behind shower installs in traditional homes, but even that stuff soaks up like a sponge and deteriorates if allowed to come into contact with any standing water. Drywall is heavy, brittle, and destroyed by water. Its use is prevalent only because it is cheap and easy to manufacture in a uniform sheet size. I would not use it in a mobile application (with vibration) and especially not behind a shower (vibration + moisture).

Not sure what system you saw for plywood, but, seal your plywood with a couple coats of oil base paint before putting PVC over it and you'll be ahead of the game. Use good flexible bath caulking in the PVC joints. You don't need to research a marketed "system" to design your bathroom stall.

 

[masterplumber]

Frp makes great shower walls, but you'll need to glue it to some plywood as its to flexible by itself. I'm not sure on the base though, with the step that's a challenge. You could maybe do a waterproof membrane, like tile base liner, but I'm not sure what you'd cover it with. If I ever build another trailer I will probably do a wet bath, using a quality fiberglass base and from over plywood walls. But the floor will be flat. Then I'll just use a porta potty so no black tank needed. I'm not familiar with the Kerdie system but I've put. Few of the knock down showers from the home centers in and I'll never do it again. The plastic is very thin and if everything isn't perfectly square they just don't fit together.

 

[VanKitten]

Drywall is far from water proof. The green stuff is advertised as water resistant, and spec'd for use behind shower installs in traditional homes, but even that stuff soaks up like a sponge and deteriorates if allowed to come into contact with any standing water. Drywall is heavy, brittle, and destroyed by water. Its use is prevalent only because it is cheap and easy to manufacture in a uniform sheet size. I would not use it in a mobile application (with vibration) and especially not behind a shower (vibration + moisture).

Not sure what system you saw for plywood, but, seal your plywood with a couple coats of oil base paint before putting PVC over it and you'll be ahead of the game. Use good flexible bath caulking in the PVC joints. You don't need to research a marketed "system" to design your bathroom stall.

That is what the Kerdi system does....makes that drywall completely waterproof.

With seven inside corners, 5 outside corners. Plus the curb ...... I just thought drywall would be a whole lot easier to build with.

 

[VanKitten]

Frp makes great shower walls, but you'll need to glue it to some plywood as its to flexible  by itself. I'm not sure on the base though, with the step that's a challenge. You could maybe do a waterproof membrane, like tile base liner, but I'm not sure what you'd cover it with. If I ever build another trailer I will probably do a wet bath, using a quality fiberglass base and from over plywood walls. But the floor will be flat. Then I'll just use a porta potty so no black tank needed. I'm not familiar with the Kerdie system but I've put. Few of the knock down showers from the home centers in and I'll never do it again. The plastic is very thin and if everything isn't perfectly square they just don't fit together.

At one point I was looking to try to buy gripset for that purpose.   But, coming from Australia..that didn't seem likely.     I found a liquid rubber membrane....hum. Liquidrubberusa.com.       Still.    What is the weight difference...drywall to plywood.
Lots of cuts to build this odd shape.

 

[BradKW]

Schluter is a big name and I've always found their products to be good quality. I've used parts of that system...towards the end you see the plastic floor grid for rest of bathroom.

Are you planning on tile walls? They obviously are fairly heavy, and there's some special things to know regarding mobile applications. I'm doing some tile and spent a good bit of time researching it, so ask for details if that's your plan. FRP would be another good solution, but at that point the Kerdi wall coat would be redundant. Regardless, don't use drywall anywhere...just the vibration alone will wallow out fastener holes quickly, plus all the other downsides. If I really wanted to use Kerdi walls, I'd use either Densglass or plywood as substrate.

I like that floor pan system, I'll have to look into that...appears it would be flexible for odd shapes too, and could easily double the curb height.

 

[TMG51]

That is what the Kerdi system does....makes that drywall completely waterproof.

Kerdi's marketing can say that as much as it likes, but I build things for a living and I can tell you drywall is never waterproof. Whether it's six months or six years something will fail and if drywall is behind your shower it will blow up with moisture and fall apart (if vibration hadn't done that already). Plan instead for the system that requires as little maintenance as possible. Again, I would not use drywall in a mobile application. But believe whomever you want!

 

[VanKitten]

Well..I am sold on plywood then.

I think I will go with the Kerdi floor pan, and see what the shower wall liquid rubber is all about.

I don't think water proofing the backer is redundant. With all the odd cuts and angles...just too much opportunity for pvc wall panels to wiggle loose over time. Do not want to tear this out in the future. Flexible "grout" cracks too eventually. Never found one that would outlast the joints...and that was before trying to do it in a mobile application.

 

[Every Road Leads Home]

I'll def agree with the others that drywall is about the last on the list of materials i'd use. Way last. Hardi backer or cement board would at least be better choices if weight isn't a concern as it is much more water resistant if water does get to it.

If I'm to ever build a shower enclosure I think I'd do it with 1/4" corian sheets. Once glued together it would be seamless. I have a background in making corian counter tops though, not sure how it would be to work with if you've never used it. It's a pretty simple process, so I think anyone with handy man skills could accomplish satisfactory results. It does require an expensive caulking type gun (around $100) that allows you to use a 2 part epoxy that mixes it as it comes out. You cut it with regular woodworking equipment and blades. Wear a mask though

Another option i've pondered is building it out of plywood and then fiberglassing it like they do when making a canoe. The natural wood grain shows through but you still have the waterproof protection of fiberglass.

 

[VanKitten]

Corian is out of my budget for the bath. Just a PVC wall panel design is it.
I saw some at Sutherland for $20 a sheet. Real thin stuff...but backed by plywood it should work.

 

[Every Road Leads Home]

I like the PVC wall panel idea. You can use PVC cement that plumbers use on PVC pipes to waterproof all your joints.

 

[Txjaybird]

Just tonite on youtube I watched Slim Potatohead build a simple wet shower and toilet space in the storage space of one of the seats in his Aliner pop up.  It folds back down when not in use.  It's very simple and the only plumbing was installing the drain thru the floor, he uses a large water container as his grey water tank.  He has many ideas that I think would work in a van as well as in a trailer.  It was the first time I'd seen him.

Jewellann

 

[VanKitten]

Ill go look it up. Thanks!

 

[VanKitten]

After finalizing some things...I have concluded that I will build this little room with plywood. I plan to use paintable rubber to seal it. This product: https://liquidrubberusa.com/pages/products

Now..how do I stick vinyl panels (or faux tile) to it?

I did a search to find how to stick Vinyl to rubber....drew a blank.

Anyone know? I feel that those "peal and stick" tiles are not going to work without another, better adhesive.
The panels would be the same issue.

 

[VanKitten]

IWell, I experimented with a few different solutions.   This is what I am doing...

The entire room will be framed (etc) then luan on all the walls.

Liquid rubber (liquid rubber USA has one that is not solvent based).  The entire room will be rubberized.  

I did a experiment project over the last two weeks, and tried 5 different adhesives to glue vinyl to rubber in a very wet situation.   I tried sikaflex, gorilla glue, gorilla contact cement, liquid nails, fuze it (new by liquid nails).     I then took the sample boards into the shower at home.  Soaked them 3 times a day for a week.

Both gorilla products let go almost immediately.   Sikaflex became loose after a couple days and then let go around the edges.   Liquid nails did OK....but that fuze it did great!   

I then sprayed them with 50/50 water chlorine.... like I might if they start to mildew (don't know that they would). Let it stand a couple hours ..as if i was killing Mildew..then rinsed again.    

Both liquid nails products stood up to this well....but the fuse it really come through without any issues.    

So...that is my solution.   Rubber with vinyl tile using FuzeIt.    I might actually use vinyl flooring in a roll if I can find something I like.

The sales rep at liquid rubber USA offered me 15% discount if I provide all my project pictures and narrative to them to publish ...  yeah, going to do that!

 

[Vagabound]

Rubber paint: 
Although I don't have any experience with it, it sounds like a cool product, and it brought up a question in my mind. If you rubberize the plywood wall with that special paint, why do you need vinyl? Or the reverse, if you're going to use vinyl, why do you need to rubberize the wall behind it? It would seem like the wall needs to be sealed one way or the other. Not the voice of experience here, just my impression.

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My wet bath dilemma:
I have built a wet bath/shower in my truck. As described elsewhere, it consists mostly of a Rubbermaid bin, two shower curtains with a custom curtain rod, and a modified bug sprayer.Two solid walls, and the other two sides open to the living space.

I'm having a challenge at the moment similar to what's being discussed here. For most of the area of the shower stall, I'm using two overlapping shower curtains which hang down into the tub to create a waterproof space. That isn't ideal for a few reasons. In any case, that has me thinking about doing something different on the back wall of the shower, which is plywood. 

The specific problem is the conflict between a sealed wall, regardless of materials, and the use of the bin as a shower pan / tub. With only a sealed wall on the back side, and no shower curtain there, any water running down the wall would continue down the wall past the crack between the wall and the tub and eventually land on the floor. At the moment, the shower curtain redirects that into the tub.

The only idea I thought of so far is to have a sealed plywood wall on the back side right down to where it joins the tub, and then install some sort of transition piece that covers the crack between the wall and the tub. Like a skirt that is tightly fastened to the wall at the top. Whatever method I use, it would have to be flexible, because I want to be able to move the tub a little bit and even take it out when needed.

Anyway, that describes my dilemma, such as it is. Any ideas welcome.

Tom