Installing second full bath in rear of h3 advice

[Gboya12@aol.com]

Good evening I’m looking at 2001 Prevost marathon h3 with two slides. I want to install in the back closet bedroom region inside the space of 3 1/2 feet deep by 7 feet wide with flat floor A full shower a head and the sink. This coach has two slides one in the bedroom and one in the front salon area. Do you think I could run the pipes forward from the rear bathroom to the front freshwater and waste. holding tanks. Will the rear slide get in the way…..?.. certainly will also be talking to Coach renovators

thanks Dr Gary
201-663-0935

[Joe Camper]

Im really curious to see what shop u find to take on a job like that.

[Fratto]

That kind of modification sounds like a "This Old House" episode where everyday you run into something you did not know or anticipate. Will be fun to hear how this goes and what the costs are.

[shahzadlateef]

Dr Gary,

I have a 2003 Marathon H3, so very similar to your coach. Technically anything is possible. First, in my rear closet, I have a lot of electronics behind Velcro lining in the walls. Moisture from the shower area and electronics don’t mesh well, so best to isolate or relocate the electronics. Access to the black and grey water tanks will need to be sloped adequately to drain well, even if the coach is not perfectly leveled. The drains pipes will have to be isolated from the engine compartment, but under the bedroom slide mechanics, and still be in a slope. The more curves you introduce in the black water drain, the better slope you will need. You will have to get around the rear differential assembly as well, while still maintaining a slope. I would think installation of a mecerating type pump with flex hose may be better than trying to perfectly slope the drains. You will also need to install ventilation. Access to pressurized water may be easier, as it will simply need some fittings and hoses.

Sounds like a pretty interesting project.

Regards, Shahzad

2003 Marathon H3-45 DS

[Hoffman]

I also have a 2001 Marathon H with 2 slides. I don't want to discourage you but this is very major work for many reasons. You'll have to reroute electrical (low V, 110, 12v, Video, hydraulic lines and more. The back of a 20 yr old coach is usually a rats nest of stuff, some of it abandoned over the years. As for your new plumbing needs, it's totally do-able, but it's not trivial to get black routed above the engine, thru the axle area and into the black tank without removing the bedroom floor and integrating it.
As for cost, I can't fathom this being do-able for less than 25k+. I think the list of unknown-unknowns is long.
Is it do-able? Sure. Is it worth it? You might want to look at a newer coach that's already has a rear bath. But don't let me discourage you.

[Gboya12@aol.com]

It’s been suggested I use some type of some pump to get all the waste liquid sent over to the black water tanks. I do worry about the slide and attempting to go below it with all those moving parts. I’m using an RV for business purposes and I will probably carry a few people with me in addition to one or two professional drivers. The extra bath and shower in the
bedroom will give me the privacy I would like plus accommodate five or six people waking up at the same time and needing the facilities. I certainly am concerned about the electronics back there and moisture so proper ventilation would be necessary. How do you spoken to a few reputable renovators and it sounds like a project of this magnitude would run $15-$20,000 possibly more. I’ve been shopping for three months and it looks like I can get a double slide 2001 or two for approximately $225,000. Therefore it pays to add a few things such as an extra four bath and three bunks. You’re Comments greatly appreciate it

thanks Dr Gary Gboya12@aol.com

[BadFitter]

Do factor in the time it will take for the modifications to be made. It won't be quick and it certainly won't be soon as most anyone will optimistically quote.

[Joe Camper]

My XL started life as a VIP floorplan rear kitchen and bathroom. The toilet was R.R up against the side wall 2 ft from the rear. My toilet drain went down the TOP of the chase that runs the length of the bus when u have otr ac. It was a raritan masserator toilet they still sell it. It discharged out the side and the plumbing went on a 45 up towards the side wall where a 90 sent it forward down the top of that ac chase. Practicly O pitch between there and 8 or 10 ft forward where it turned down to the floor. 1 1/2 pvc is all it was. Also had a water closet right behind the driver same stuff sept it drained the other way. The kitchen sink and bathroom sink were both on the back wall and they drained forward up both sides obviously to assist with unlevel situations. Worked great. Never had a drain issue even way high in front . The traps for those vessels were well above any angle i ever parked at. The shower stall would be more critical. The trap for that was forward where it turned and went below not directly under the shower pan and that never seemed to be a problem either.

Plumbing and moving it will be the easy crap. The other mention of all the electrical controls marathon puts back there. Big big big job to rearrange. With all the work out there now and shops burried u would be hard stretched to get a taker.

Besides that I think that any savy prevo owner who has done this for a while would never attempt it nor would any proper conversion shops, in my opinion that is. U might.

R u willing to let a shop do it for time and material with an open checkbook thats probably what it would take. If some shop actually tried to quote u in advance that to me would be a huge red flag.

A good shop that could do it right, to get a quote in advance....it would be 2 or 3 times more than they would estimate it actually costing in thier wildest dreams to be safe. Either u r run off or u agree to crazy terms.

A decision to do something like this hindges right on the edge. On multiple levels.

[Gboya12@aol.com]

I said listen to everyone’s advice I greatly appreciate your comments. Perhaps if I were only to put a head and a sink in the rear of the H3 2001 Prevost marathon double slide that would solve some of the moisture problems. Does anyone have any thoughts about that change of plans

thanks Dr Gary. Gboya12 @aol.com

[Joe Camper]

First I have to say IMHO u r putting way too much inportance on a second toilet nice but not worth the effort modifying to get it. And I even love the ones that the converters do great floorplan.

That said if thats what u want....

Have u ever seen an "executive" or a VIP floor plan that would be a better fit for u and easier to modify to what u want.

Have u considered an entertainer coach. They already have front and rear lounges and the 4 stacks of bunks up the middle could be pulled in 1 morning and then the skys the limit and it would be way easier than modifying a motorhome. The initial cost would be way way less as the conversion costs as well. Prob easier to get a shop to complete it too.

How bout this. Im still assuming u r not using the bedroom but hotels along the way. So get thst Marathon u llike and pull the bed build a wrap around couch with a small table in back. Keep exzisting bathroom and just add a water closet with a toilet and small sink up front with a motorhome floorplan. Way less complicated and costly.

Doc i gotta say u r relentless. U need a Pulman Car.

Call the Hempel Brothers in Nashville pic their brain or other such shops.

Creative conversions or something like that think they r a sponsor here out of ohio they might be of
assistance.

Try Wayde and Libby at Stayley Coach tell them what your looking for and my sugestions see what they say. See if they currently have any Senators entertainers for sale. These r nonslide XLII. they r well built and well maintained and they look real good too. All Silver 2 tone light and dark. The front and rear lounges r leather and very very high quality finishes. These r often on the market they r out of Florence alabama but use stayley for selling them after they put a few yesrs on them.

Another thing a kitchen table with 4 chairs makes way more seating space and will sit 4 people way more comfortably than a booth.

What fun spending other peoples money.

[Joe Camper]

What possible reason would u have for a second shower i just noticed u want 2 FULL baths. Comeone

But here is another plan. Get that Marathon u like. Be sure it has OTR AC no slides.

Get it with 1 couch and chairs other side and if u could find it with table and chairs no booth even better but most marathon i can recall have booths.

So empty the livingroom and kitchen furnature. Couch tables chairs booth all. Save it Disassemble corectly.

Directly behind the driver put a water closet with a toilet and sink. The water supply and drain simple right down the wall to the plumbing bay and through the floor drivers side where u dump already. Then fill the rest of the space with nice captians chairs thst recline footrests top shelf chairs. some flip out tables on them. u could fit plenty easy. Say maybe 3 across with a good isle maybe 4 across and comfortable with really nice captians chairs. They could be fitted with seat belts all of them. Then pull the bed same thing or do a lounge wrap around couch with table or something back there. Same thing save everything removed.

U retain the original full bath and When u were done with it it could be almost put back if the next guy wanted.

[Gboya12@aol.com]

Thank you so much for your response and you raise valid points.Perhaps it’s easier in the back closet to just to put a head and a sink this way I don’t have to deal with the moisture problems of a shower . My game plan is to have a professional driver plus have two or three friends to travel with me as I go from state to state that’s why I want a second private bath and extra bunks


I’ve already looked at 30 buses from Staley coach and buses for sale everything I saw was beat up and worn out. I think you raise great point about having four chairs instead of spending the money on a dinette with benches. I wonder if there is a way to anchor the chairs to the floor and have seatbelts. I certainly will be attempting to get the coach inspected by Gill Johnson if he’s available

thank you Dr Gary