Plumbing question - need opinions please

[tojoski]

I'm putting a small bathroom in my shop and running a 4" PVC line back to my septic tank near the house.. Well now that the shop is up i re-checked my distance and fall and i ended up with about 10" of fall over about 168 feet.

This works out to almost 1/16" per foot.. I know the usual recommended fall is 1/4" per ft, it I have seen some posts around the web that say 1/8" is ok

What do you guys think? I guess my only options are either to add a pump or put in a 2nd septic tank.

Thanks

 

[RVDan]

In my opinion 1/8 is sufficient for short runs, but I'd think 168 feet is a bit far for 1/16. The water will run out of momentum before the end of the run, and leave the solids behind.

Another option might be to elevate your bathroom?

 

[nmanitou]

That's pretty flat. A pump is your best bet. If you do risk it with a flat slope I would put in a 2 to 3 cleanouts along the pipe for easy access.

 

[Clik]

PVC is slick. You won't have any problem. I owned a commercial Sewer and Drain Cleaning company. Forty years in the biz. Cleanouts are cheap and easy. Install many.

Your not likely to be washing dishes so grease build up won't be a problem. I have had stoppages in commercial shops caused by a build up of grit in handcleaner. Use the type that doesn't have sand in it or wipe it off before rinsing.

 

[tojoski]

This will be for a toilet only....the sink being just grey water will just run out on the ground.

The only thing I'm really worried about are solids. The bathroom won't get used all that much though.. maybe I can find an old school toilet with a 3-5gal flush

 

[Tim The Tool Man]

As others have said, install several clean outs. However if you get any significant freezing you might end up with some issues...

 

[rasit]

This will be for a toilet only....the sink being just grey water will just run out on the ground.
The only thing I'm really worried about are solids.

If you hook the sink into this line it will help to keep the solids rolling along....As others have said, install clean-outs. I would put one just outside of garage and two more along the run.

 

[Steevo]

This is precisely why I put the bathroom halfway to the back of my shop rather than all the way back in the corner. It would have been too shallow a slope to where I had to pick up the sewer up at the house.

 

[kbs2244]

Flush twice

 

[curly8888]

the only thing i can add would be make sure there are no burrs in your connections to catch anything

 

[brownbagg]

You dont want it too steep or the water will out run the solids

 

[brownbagg]

did a hole closer, add two 55 plastic gallon drum hook in series, add about twenty foot of field line in gravel

 

[slip knot]

Look into re-sizing your line. You want 2ft/sec flow and the 4 in may be too big but a 3in may be better as far as ft/sec. You dont want to water to outrun the solids but to carry the solids away. I've redid some soil lines with 3in and have never had an issue.

 

[White 99]

Mine has the opposite problem; mine is too steep. But as was mentioned above it does not see hard usage. Also as mentioned above the sink hooked into the line gives more options. So far mine has been OK.

 

[Tim The Tool Man]

LAXATIVES! If you keep your bowel movements on the runny side there won't be any solids to cause a back up.

Just sayin.

 

[Lotek]

LAXATIVES! If you keep your bowel movements on the runny side there won't be any solids to cause a back up.

Just sayin.

Well played sir.

 

[tojoski]

LAXATIVES! If you keep your bowel movements on the runny side there won't be any solids to cause a back up.

Just sayin.

LOL, well thats one option.

Thanks for all the info guys.. I've already bought the pipe so re-sizing really isn't an option at this point. From what reading I've done, larger pipe is for some reason more forgiving about slope.

It is sch40 Solid Core, so hopefully that will help with the sagging..and with any potential future crushing being so close to the surface.

I do intend on doing the slope of the pipe with a laser, i can always let it settle, then re-check it and add some fill where necessary.

I was originally planning on putting a cleanout at each end, but I'll go ahead and put a couple in the middle too. I just don't want this to turn into the kind of thing that has to be cleaned out every time the bathroom gets used.

Is there such a thing as an electric pump that goes outside that would activate each time the toilet is flushed?

 

[FXDawg]

The problem you'll have;
A sag will destroy the whole thing. The slightest sag at that angle and you'll have a collection somewhere. Do the 'many cleanouts' as you'll need them the moment the fill dirt settles....

This is exactly what I was thinking. I would go with an ejector pit and a pump or a composting toilet.

 

[pmiranda]

Or only put a urinal out there and run to the house for more serious business.

 

[Kevin54]

A cleanout towards the head of the line will be sufficient. No need to put multiple cleanouts. Just make sure you have the cleanout headed towards the septic tank. 1/4" per foot is the standard, but a little this way or that way will still work. You just don't want it so steep that the liquids go down before the solids. You will be going more towards level. You may have to use the cleanout once in a while, but you should be fine.

 

[HeelSpur]

Or only put a urinal out there and run to the house for more serious business.

My urinal is a coffee can

 

[BD1]

Is there a local requirement for clean outs ??? I would install at every 50'. If you do have a blockage, 168' is a longgggggggggggggg rodder. How far below grade is the line ??

 

[J4nss(WNY)]

I would reduce the pipe size to 3" and be sure to buy a 1.6 gpf toilet while uou can still get one. All manufacturers are in the process of switching to 1.2 gpf. Better yet look for a used (but clean) 3.5gpf. Also install a couple clean outs along the run.