What is under the "bathtub"?

howdy all

I am new to this forum, and indeed to the rv lifestyle in general.  I just purchased a 26 ft. 5th wheel, my first ever trailer, which I plan to renovate and then live in.  She is 13 years old and has seen better days.  She seems structurally sound, but the interior is very outdated... not to mention grimy.  Because of this, I am going to do a complete remodel on the interior in order to make it more of a trailer'home'.  I consider myself to be "handy" enough to take on this task, but as this is my first rv remodel, im sure i will run into some head-scratchers.  Hopefully the kind folks on this forum can help me through those moments...


regarding the bathroom, the plan is to put in pergo flooring and a ceramic toilet, both of which seem fairly straightforward and i feel confident in my ability to install.
She has the standard shower/bathtub that is most commonly seen in a trailer.  however, after looking at it closer, i have noticed that the way that the "bathtub" was molded seems to have left the floor of the shower about 4 or so inches above the level of the bathroom floor.  since the total height of the shower stall is about 6"1', and the total height of my body is 6"2', i have become VERY interested in acquiring these additional 4 inches.  i really want to pull(rip) out the bathtub and install a tiled shower stall.

SO, my first (of many) questions is:

What is under the shower/bathtub?  i mean, is there a valid reason why it was molded to sit 4 inches above floor level?

at first i thought that maybe it was sitting on top of the grey water tank, but after looking underneath the trailer i no longer believe that is the case. 
i am really wanting to pull that tiny shower/bathtub out and install a proper tile shower stall. 

also, if i DO install a tile shower, do i have to buy a shower pan, or can i just make one out of backer board and tile over it?
(i have never installed tile before, but feel confident that with a bit of instruction i can)

if you have no idea what i am describing, perhaps tomorrow i can post some pictures, once i take ownership of the rig.
thanks in advance for any help rendered.
-Matt

I dont see any reason why a shower stall base wouldnt gain you a few inches. When you say tile, what are you meaning. If you mean ceramic tile, that wouldnt work too well if you ever plan on towing the trailer again. Trailers have too much flex in them and ceramic tile wont take any kind of movement without cracking the grout. I would recommend a composite board like ceramalite, which is available at Home Depot. It looks like ceramic tile but comes in a sheet. You just caulk the joints. It is commonly used in tub surrounds.

If raised 4 inches, I would imagine there "is" something there - such as the upper part one of your holding tanks. Another reason they do that is for electrical and/or plumbing stuff. They would rarely just leave a 4" by whatever the dimensions of your shower are, empty.

Is there some way you can take a look? There is a removable deal under my shower stall that I can remove. Also, you may want to take a look outside where the bath is located and take a look in any compartments in that area that would give you a clue. For example, I can find all of my black, gray, and fresh water tanks by opening various compartments. In the rear of my MH, there is a compartment that goes the width of the rig - and I can see in the bedroom how that area is blocked off otherwise.

My entry into this discussion is to use a shower pan and the "snapstone" floating flooring, never used it but their website looks interesting enough for consideration.

If the floor is raised up 4 inches you can bet your life there is something underneath there to warrant the raised floor. Space is rarely wasted in an RV like it is in a lot of stick and bricks.

nothing under my shower, that's where I hide my guns and money when I go to Canada and Mexico.

I haven't looked, but I always assumed it was to gain space for an 'S' or 'P' trap.  If that's the case in yours, you certainly wouldn't want to do away with it.

My guess is to leave space for the "P" trap, also - to simplify the plumbing by keeping the trap inside the rig and maintaining a downhill run to the inlet of the grey holding tank.  Usually the inlet is through the top of the tank and adding the height of an elbow above that extends the inlet height to either the interior floor level or somewhere slightly above it.

You don't want to eliminate the P trap, and you don't want to end up with an uphill run to the inlet of the grey tank.  But it might be possible to gain a couple of inches by cutting a hole in the floor and letting part or all of the P extend through it - especially if the bathroom is already a step up from the rest of the floor.

Or you could go the other way.  Usually the ceiling is framed with at least 2x4s.  You could cut away the headliner inside the shower and gain headroom up to the outer roof.  Frame in the hole around the top of the shower and add a bubble skylight or just use a piece of translucent plexiglass to fashion a flush skylight.

Or you could just cut off your feet 8)

Seriously though, I live in an RV full time and I don't even use my shower. Most every RV park has showers and by using their showers I save on propane since I don't bother to ever turn on my water heater. And I can take really long showers in a shower stall that is actually big enough to take a shower in.

SeilerBird said:

Or you could just cut off your feet 8)

Click to expand...

You silly rabbit.  It's his head he's worried about, not his feet. ;D

thank you for all of the suggestions.  i am happy to see that this forum is relatively active.

Lou Schneider said:

You don't want to eliminate the P trap, and you don't want to end up with an uphill run to the inlet of the grey tank.  But it might be possible to gain a couple of inches by cutting a hole in the floor and letting part or all of the P extend through it - especially if the bathroom is already a step up from the rest of the floor.

Or you could go the other way.  Usually the ceiling is framed with at least 2x4s.  You could cut away the headliner inside the shower and gain headroom up to the outer roof.  Frame in the hole around the top of the shower and add a bubble skylight or just use a piece of translucent plexiglass to fashion a flush skylight.

Click to expand...

the shower features a skylight with a dome, the added height of which i have already included in the overall 6"1' measurement.  when i am standing in the shower, most of my head is inside the skylight... so i want to eliminate that "george jetson in a bubble dome" feel.  i think that you have struck on something with your comment about lowering whatever may be under the bathtub... as the bathroom is a step up from the main living area, i think this may be a legitimate possibility.  i think that there is a storage compartment underneath the shower and above the tank.  my guess is that the shower could have probably been constructed flush with the floor, but the mfg had a bunch of these standard bathtubs laying around and it was cheaper and easier for them to use it instead.  when i take ownership of this rig tomorrow, that is going to be the first thing that i examine.  thanks again for the idea

Depends on the layout of your rig but the raised floor is probably there for a better reason than "we have extra of these in the warehouse."

The shower in my trailer has a raised "bench" in it for the wheelwell.

4" would be enough for furnace ductwork, or a P trap.

Bob Buchanan said:

They would rarely just leave a 4" by whatever the dimensions of your shower are, empty.

Is there some way you can take a look? There is a removable deal under my shower stall that I can remove. Also, you may want to take a look outside where the bath is located and take a look in any compartments in that area that would give you a clue.

Click to expand...

thanks for all of the replies!  as it turns out, there is a access panel on the wall behind the shower, such as there is on most residential homes.  i was not expecting an rv to have such easy access to the plumbing.  anyways, i removed the access panel and took a look...

http://i35.photobucket.com/albums/d152/mattlock1983/IMG_05841.jpg

and i found a dead mouse!  gross!  also lots of mouse poop and a rats nest.  that right there is a good enough reason for me to want to rip this tub out. 

Jammer said:

Depends on the layout of your rig but the raised floor is probably there for a better reason than "we have extra of these in the warehouse."

Click to expand...

actually, it looks like that was exactly the case.  i guess the mfg wanted to save money by using the standard tub, which appears to be molded with the raised 4" bottom in order to clear the u trap and other plumbing when sitting on the chassis floor.  however, my bathtub is not sitting on the chassis floor, it is sitting on top of the storage compartment which holds the water equipment.

http://i35.photobucket.com/albums/d152/mattlock1983/IMG_05851.jpg

http://i35.photobucket.com/albums/d152/mattlock1983/IMG_05861.jpg

here is a view from underneath, looking up from the storage compartment under the shower.

http://i35.photobucket.com/albums/d152/mattlock1983/IMG_05871.jpg


what it looks like to me is that the u trap is almost level with floor level, maybe an inch higher.  i might not be able to install a shower pan directly on the floor, i might have to block it up about an inch to clear the plumbing. or i could do it the right way and lower the plumbing a few inches.  i have not decided what i am going to do, but at the moment one thing is certain... the tub is coming out!    also the toilet too, i just ordered a new ceramic toilet from campingworld this morning!

Most shower bases have the drain in the center. You will have to replumb the drain over. The other option might be to make your own base and leave the drain where it is. You will have to slope the floor of the shower to the drain. If you go to a plumbing wholesale store (not Home Depot), you could inquire as to the different products available. Might be easier to just move the plumbing to the centre and use a standard shower base. Looks like you have a vent pipe going up from the holding tank there as well. I assume it could stay inside the wall where it is now.

i have been looking for shower pans online, and they are much more expensive then i thought that they would be, or should be.  also, i am having a hell of a time finding a shower pan small enough to fit.  the dimensions of the tub are 24 x 36 inches.  there are plenty of 36x36 shower pans, but since the bathroom is only 4 feet wide, any increase in the width of the shower would correlate in an equal decrease of toilet space.  i thought about blowing out one wall and expanding the bathroom, but due to the slide being on one side and the bedroom on the other, it would simply be a major amount of work just to gain 6 or 7 inches of width.

i was able to find some correct sized bathtubs on a rv website, but they look pretty much exactly like the one i am replacing.  i was also able to find some proper sized shower pans, but the drain is on the wrong side and  i would prefer to complete this remodel while doing as little plumbing as possible.  so, after further consideration, i might just reuse the old tub and just lower it to sit flush on the ground.  once i lower the tub and gain the additional headroom in the shower, i will either reuse the old shower surround and add white frp board between the celing and the top of the surround, or i might just toss the old surround and use white frp board entirely.  i have not decided yet, but i feel that the limiting factor will be the budget; including the pergo and paint, i am already close to the budget limit i set for the bathroom, and i still haven't even ordered the nickel shower fixtures and extend-a-rod yet.

If you reuse the existing tub, lose the styrofoam block underneath the pan and firmly support the bottom and the curved edges of the tub.  Those are the weak points - the styrofoam compresses over time, then the floor sags and as you walk around in the shower the plastic flexes until it cracks.

The plastic tubs are fine for weekend and vacation use, but they're really not up to fulltime demands unless you reinforce them.

You probably won't find a residential shower base less than 900 sq in. That's  the building code in most areas. Mobile homes however don't go by most building codes.

A shower base could be built the dimensions you want, framed up with plywood and waterproofed with pan material, or bend one up out of sheetmetal and waterproof with dryloc.

When I first started plumbing we had to bend up and solder a shower pan from lead sheet, that would still work well.

thanks for those informative replies!  catblaster, i really like the idea of making my own shower pan, then presumably putting tile over it and doing a tile surround for a very custom looking shower in my RV.  unfortunately,  doing so would break the current budget for the bathroom remodel.  so what i have decided to do instead is to simply reuse the old tub and surround but freshen them up.  i plan to use this product:
rust-oleum tub refinishing kit
on the old tub and surround, hopefully making it look brand new, and making the tub slightly stronger too.

lou, you are right about the tub being flimsy at best.  the plastic in the corners is so thin that i can almost see through it.  i will trash the piece of foam that is under it and instead cut out a piece of plywood for the tub to sit on.  that piece of plywood will be the only thing between the tub and the floor; i have already removed the "riser" that the factory installed the tub on and the carpet, so when i re-install the tub it will be 4 inches lower than it was before.  the entire tub and surround are easy enough to remove from the trailer, so if (when) the tub eventually cracks i will pull it out and finally install the custom shower pan and tile the whole thing.  but for now, i am gonna go the cheap route.  saving money on the shower allows me to ponder the possibility of installing underfloor heating in the bathroom/vanity...

what is the general consensus about installing something like this:
radiant floor heating
underneath of something like this:
cobalt slate laminate flooring
i am considering installing underfloor heating in the bathroom/vanity for a few reasons.  obviously, the first is because it will be nice to have.  secondly, where it would be going is also directly above the compartment that stores my freshwater tank, and i think that it might help keep the tank from freezing.  and C: where it is going is also right next to where my inverter will be installed, so getting 110 power to it should be simple.  any advice or reservations about installing it in a bathroom?

When I worked residential many years ago, we would put cement under the fiberglass tubs. First was a sheet of plastic, then a mound of wet cement and cover it with another sheet of plastic to keep it from sticking to the tub bottom. Mash the tub into the mound and let it set up. I did this on our cheap fiberglas tub in the house 25yrs ago and it's still solid.

You could also make the shape you want and lay fiberglass over it. However it is a lot of work. I bought some fiberglass mat off of E-bay a few years ago, and made my own fiberglass parts for a race car I built. Nobody made the parts I needed in the aftermarket so I made them myself. If you use fiberglass, it would be water proof and then use your tile over.