Basement toilet 'problem'

[tropics surfer]

we have installed an American Standard Cadet in the basement and the builder did not put a vent in the upstairs toilet line. I've read here about problems with the Cadet and am wondering if the toilet is the actual problem. What happens is when the upstairs toilet is flushed, water splashes upward in the bowl of the Cadet, enough to leave water on the inside of the seat cover.
This is all concrete and block construction, so what's done is done.
We installed a vent with a "y" pipe below the upstairs toilet, as high as possible, but it doesn't help. It's a screen placed over the "y" opening. Would covering it help?
Both toilets share a common 3" pipe, which runs outside the wall just below the upper floor, but the rest of the pipes are buried in either the walls or 5" of concrete floor.
Upstairs model is Glacier Bay, 1.28 lpf, and both models were purchased in 2011.
Friends who visit have 'charms and challenges' when staying with us!

 

[Terry]

Normally I would plumb stacking bathrooms like this.
I plumb using the UPC code, which vents toilets. Bringing waste down the vent pipe will force water out of the lower bowl, as you have noticed. Normally you would wye the lower toilet in so that the plug of water wouldn't create pressure that forces water up in the bowl.

 

[Sponsor]

 

[tropics surfer]

thanks for the reply. It would take a lot of demolition in solid concrete (and blocks and rebar) to fix things now, as you've diagrammed, so it's pretty much out of the question.
the basement is basically a hurricane shelter so it doesn't get used a lot. So, I guess replacing the Cadet with a higher end or larger model wouldn't accomplish anything?

 

[hj]

How the downstairs toilet is connected to the system may be relevent, but we do not know how it was done. If there is a "back pressure" in the line then it would compromise the toilet's flushing. Sometimes the bowl is made improperly, and the water jet hits the back of the toilet instead of going into the waste passage. We would have to be there and make our own tests to evaluate your condition. I cannot figure out how you installed that "Y" properly and would then have an opening you could put a screen over.

 

[tropics surfer]

The Y was put in when a new employee came on the job. He knew the upstairs toilet should have had a vent, but by then it was too late to put it in the proper place, so, the 3" sanitary pipe, which is the only one that runs outside the walls was the only place. We left the Y open but had to screen it so critters won't move in.
I wish I could draw a diagram- maybe iIcan get some help with that. The "Y" is open at one end-it was an effort worth trying...
We are in rural mountains and we went with a local handyman for the building. He did very well for most of the construction, but we found out too late that it's a custom here that when you're paying someone to do work, they'll never tell you that they don't know how to do something (you might bring in someone who does, and they'd be out of work).

All being said, this was a big build, and we're happy with 99% of the work. We could have gone with a local pro with a large crew, but it would have cost another 20k.
Again, both toilets flush fine. It's only pushing water up into the lower toilet when the upstairs one is flushed.
So, the only options are? Replace the small Cadet downstairs, or, nothing? Thanks again! Appreciate the help.

 

[Hackney plumbing]

The Y was put in when a new employee came on the job. He knew the upstairs toilet should have had a vent, but by then it was too late to put it in the proper place, so, the 3" sanitary pipe, which is the only one that runs outside the walls was the only place. We left the Y open but had to screen it so critters won't move in.
I wish I could draw a diagram- maybe iIcan get some help with that. The "Y" is open at one end-it was an effort worth trying...
We are in rural mountains and we went with a local handyman for the building. He did very well for most of the construction, but we found out too late that it's a custom here that when you're paying someone to do work, they'll never tell you that they don't know how to do something (you might bring in someone who does, and they'd be out of work).

All being said, this was a big build, and we're happy with 99% of the work. We could have gone with a local pro with a large crew, but it would have cost another 20k.
Again, both toilets flush fine. It's only pushing water up into the lower toilet when the upstairs one is flushed.
So, the only options are? Replace the small Cadet downstairs, or, nothing? Thanks again! Appreciate the help.

Are you flushing into a septic system? You may need to install a vent down stream of the downstairs toilet.....this could even be outside if the toilet is the last fixture before the building drain hits the septic tank.

So you on a septic tank? How many plumbing vents exit the roof of the building besides the one you added?

 

[tropics surfer]

Yes, flushing to a septic tank, and yes the toilet is the last fixture before the drain hits the tank.
No vents were installed in the roof at all, except the one we added, but it is below the upstairs toilet by about 16", and it's obviously not working.
A vent downstream of the last toilet is possible as the drain runs about 25 ft. to the septic tank. But wouldn't it emit odors with a chimney effect from the septic?

 

[Hackney plumbing]

Yes, flushing to a septic tank, and yes the toilet is the last fixture before the drain hits the tank.
No vents were installed in the roof at all, except the one we added, but it is below the upstairs toilet by about 16", and it's obviously not working.
A vent downstream of the last toilet is possible as the drain runs about 25 ft. to the septic tank. But wouldn't it emit odors with a chimney effect from the septic?

Add a vent between the last toilet and the tank to the open air above the roof line.

 

[tropics surfer]

Hope this image posts. Adding a vent requires boring a hole through 5" of concrete and rebar because of the ledge (24") overhang which was needed for construction, (or routing around it?) then boring a hole through the plywoood and steel roof. It would look like a Rube Goldberg contraption, be subjected to hurricane force winds and, because we get 6 ft. a rain a year could pose other problems.
The house is on a hillside and the toilet drain line runs downhill in front of the structure laterally.
The only viable option I see is replacing the Cadet in basement or living with the inconvenience..

 

[Jadnashua]

Replacing the toilet with another won't do anything. An open vent in the house will just let the gasses from the septic system into the house! Worst case, you can rent a concrete boring device...nice clean smooth holes quickly.

EACH fixture should be vented individually (there are some exceptions, if done right, for a fixture group - a bathroom). The reason for vents is not to drain better, but to prevent the draining of one fixture suctioning one or more others dry, again, giving you an opening directly into your septic system. On the roof, you could put a 180 on the top to prevent rainwater from adding the water to the system, but consider, a 2-3" diameter pipe wouldn't get much water into the system and if the rest of it is working properly, should be no big thing.

 

[Hackney plumbing]

Put the vent outside between the house and the septic tank. Just install a cleanout and leave the top off. LOL

Seriously just install a tee and run a pipe above ground and turn a trap upside down on it. Better than having crap and gas blowing in the house.

 

[Hackney plumbing]

When you flush the upstairs toilet that water displaces air......it pushes air. t\There are no other vents downstream so the air is pushed out of the toilet downstairs blowing crap everywhere in the process. Adding a vent before the tank will allow a place for this air to escape outside. Not the best way at all but better than it blowing up in the house.

 

[Jadnashua]

There's a reason why vents go out through the roof...they stink. Having one down low potentially may significantly degrade your pleasure in using the area where it is discharging. I wouldn't want a ground level one unless it was a long ways from the house, and even then, depending on the wind directions, might not be enough.

 

[Hackney plumbing]

There's a reason why vents go out through the roof...they stink. Having one down low potentially may significantly degrade your pleasure in using the area where it is discharging. I wouldn't want a ground level one unless it was a long ways from the house, and even then, depending on the wind directions, might not be enough.

Not all vents go through the roof. Grinder pumps vent right at the basin in the yard with an upside down p-trap.

 

[Hackney plumbing]

When a house is below the manhole of the city sewer we install relief drains. All we do is cut in a cleanout tee.......extend the pipe above ground and couple feet and turn a 4" trap upside down so things will not fall into the sewer.

If the city sewer backs up it overflows in the yard instead of filling the house with sewage. Backwater valves are not reliable enough

If the open low vent causes an issue......then simply correct it. Dig a trench to a location away from people or to a place where the vent cant be directed up to the roof.