1974 Sovereign Bathroom Relocate

[DoubleD49]

Has anyone had experience relocating a rear bath forward? I would like to have the bedroom in the rear and move the bathroom forward with the toilet/sink on the right side and a shower on the left side. This would be similar to the Classic 30 floor plan.

[themostream]

One issue with moving the bathroom location seems to be the location of the vent openings in the roof. The vent allows air to escape out of the top of the tank as it is filled. Otherwise you can end up with an air bubble that limits the capacity. I'm not sure how much of an issue this is for a black tank where you open the valve to the toilet every time you flush, but the above floor black water tank on my '73 was vented before I took it out.
You could work around the vent and black water tank by installing an composing toilet, but the best reviewed of those have a fan to dry out the solid waste, and would require a vent for the moisture/stink to escape.
A grey water tank will definitely need to be vented, otherwise the air pressure buildup will restrict its usable capacity. You can marry the black and grey vent pipes together before they go through the roof, but that limits their placement. You will want to join the vents up hill of the shower drain and toilet to prevent one tank running over into the other.
If you want to move the tanks you'll need to move the vent outlet through the roof. That involves patching the old vent hole and cutting a new one. This is a little scary with the potential for leaks at the patch and outlet, and having to cut into the exterior skin.
You will also need to connect the tanks to the current dump valve, or more likely move the dump valve closer to the new tank location. The structure of the frame wont really allow running a drain pipe across the trailer without cutting cross members and you won't want to get into that.
You'll need to cut a new hole in the subfloor to outlet the black tank and open up the belly pan to put in the dumb valve.
So you could do it. How much of a pain it is depends a bit on how far down you want to take your trailer apart. I'm doing the Full Monty on my '73 to replace the sub floor, so I'll be adding a grey tank since that year didn't have one. I am also going to split the bath like you're thinking about. But I've got nothing to loose since I was going to have to re-plumb the thing anyway and mine is a mid bath so I've already got a vent hole in the middle of my roof.

[Starstream]

We have a center bath, and unfortunately it's not that easy to relocate rear tanks to the middle. They aren't the same shape, and belly pans are designed to hold specific tanks. Very little wiggle room in there, for good reason. If you have a service manual it should show you exploded drawings of all components. The manual will usually have the different floor plans a trailer comes with. If your trailer didn't come with the service manual, we might be able to scan the bathroom/plumbing pages from ours. But I can't guarantee they're exactly the same since we have different model years. PM if you're interested, in case we can't relocate this thread.

[Al Boondy]

My 73 excella center bath's grey tank vents on the street side thru a closet, this vent could be used for shower drain so split bath is not going to be that big of a deal for me.
These tanks are available.
If you are removing floor belly pan etc converting to center bath not that much more work. New grey and black tanks are less than a grand if I recall correctly
Your windows may be your biggest problem.
If you need pics of my frame to compare with yours let me know. You will have to add brackets to support tank pans but I think crossmembers are in the same place.

[ijustlee]

The windows are a problem to work around and if you want side windows in the bedroom it might be less work over all to sell your trailer and buy a mid bath model? I don't know how many trailers were sold that were mid bath though. It does seem that most Airstreams were sold with rear bathroom. The wheel wells and windows would require some clever design to work around in my opinion but I'm sure somebody has done it.

[Starstream]

I probably should have specified original tanks are difficult to move. Rear baths are usually in those rounded back corners. Center baths have rectangular tanks. If you're relocating the bathroom, new tanks, not necessarily for AS could be used.

Beyond windows, before moving anything underneath, you need to know how your chassis is constructed. They are not standard across models. The space between the floor and belly pan bottoms isn't that deep. The tanks sit between the beams of the chassis. In our center bath model, the freshwater tank is above the axles. The gray and black tanks are just behind. All run horizontally from side to side. If you're doing anything with tanks in the center of the trailer, the best time to work there is when the axles are off for replacement. For a trailer that travels, it's a good idea not to make those ABS pipes too long. Good possibility something could crack while you're bouncing down the road.

As far as center bath models are concerned, yes, 70s' models are rarer than rear bath. Just try finding replacement tanks that are the correct size and shape. Our freshwater was easy. We got lucky the black and gray were in excellent shape.