Bathroom location tank

[dougyes]

Our plans for the bathroom does not put the toilet directly above the bay with the black water tank. This is what we are thinking: Mount a 5" high tank directly under the toilet. The lenght of that tank extends beyond the bathroom (behind a cabinet) which puts one end of it directly over the bay with the black water tank. From there it is plumbed with a 4" pipe straight down to the black water tank. Is this a better plan than running 4" drain pipe horizontal over the floor then down into the bay? Or is there a better solution for moving toilet waste 4 feet horizontal to the ideal drop point?

[Len Silva]

I don't think four feet is going to matter a whole lot.  I know the common wisdom is to put the toilet directly over the tank but I have seen some that were 6 feet or more away and they worked fine.  It may take a little more water to flush.

The only time I would be concerned is if you are a dedicated boondocker who needs to conserve every drop of water.  Then, I would put it over the tank just for conservation.

[desi arnaz]

"in this time of drought and sun we don't flush for number 1"

[Dreamscape]

Our toilet is at least 5' from the tank. PVC on a slope works great, just make sure the solids hit the tank after the flush.

Forgto to mention, ours drops right throught the floor, over the dual axle, then slight slope to the tank. So far it has worked great!

[1960eagle]

Great post,have been thinking about the same thing as my fuel tanks are directly under where my toilet will be.was going to move them so my black tank could be right under the toilet.    Thanks.      {maybe i could design someway to run engine of black tank  waste?   hahaha.}  Got my oil leak fixed today!

[robertglines1]

now doing rear bath...using mas-erator pump and 10 gal aux tank with level switch to pump. Will have washer ,sink ,shower.and toilet in rear bath area.

[PCC]

      {maybe i could design someway to run engine of black tank  waste?   hahaha.}  Got my oil leak fixed today!

Had you not fixed the oil leak, you could have blamed it all on the blacktank waste. which IS biodegradable.

[TomC]

My toilet is on the right side of the bus (I have the bathroom built around the rear entrance on my transit) with my tank running lengthwise between the frame rails in the center of the bus.  Hence, I have about a 3ft pipe to the tank, then another 4ft of pipe to the drain.  Only had one clog-where my wife was afraid of using enough water to flush.  Just pre filling the toilet when you do drop in with about the same amount of water as your home toilet works just fine.  Just make sure you have a continuous drop on your drain.  Good Luck, TomC

[Sam 4106]

I would use 3" PVC pipe, instead of 4", run direct from the stool to the tank. You will move the solids just as well with less water and take up less space. Put as much slope to the pipe as you have room for in the event that the bus isn't parked level.
Good luck, Sam Mc8

[gus]

Doug,

My waste system is not like most others. It was that way, except for the tank vent, when I got it four years ago and I see no reason to change so far.

My toilet is not connected directly to the tank. It is on the opposite side of the bus from the tank (one tank only). The toilet pipe passes forward into the next bay, then across that bay back into the rearward bay and then into the bottom of the tank instead of the top!! It has very little slope anywhere and there are two 90* Ls in the line?? The total length must be around 12".

According to everything I've read on the forums this won't work, but it does, even on an opposite slanted parking spot?? It was on the bus when I bought it and it works fine.

The only thing I can figure that makes it work is that we always use plenty of water to flush solids. Our toilet has two pedals which allows adding more water to the bowl without flushing, which we do for solid waste.

It seems to me that not having the toilet empty directly into the tank is much better than looking down through that big hole at all that mess every time the toilet is flushed. It works well so I see no reason to change.

[kyle4501]

Our plans for the bathroom does not put the toilet directly above the bay with the black water tank. This is what we are thinking: Mount a 5" high tank directly under the toilet. The lenght of that tank extends beyond the bathroom (behind a cabinet) which puts one end of it directly over the bay with the black water tank. From there it is plumbed with a 4" pipe straight down to the black water tank. Is this a better plan than running 4" drain pipe horizontal over the floor then down into the bay? Or is there a better solution for moving toilet waste 4 feet horizontal to the ideal drop point?

Horizontal piping with a bit of slope to the tank isn't a problem if water is plentiful. The problems arise when you want to minimize water use. We can go over a week with a 30 gallon black water tank (family of 4). The paper is what seems to take the most water to rinse away.

If you put a dump valve on the outlet of this 5" tank, you will have an excellent solution to the problem, plus, you will have added to your black tank capacity!
I am a big fan of building it so it will allow minimal water use - that way you can use as much or as little as you like. The less water you need for flushing, the less you have to carry -OR- the longer you can go on a given tank size.

Your idea solves the dilemma I have been struggling with on my bathroom plan - now, I can locate things where I want them.

THANKS!