Basement venting-Is this right?

[littlebrook]

Hi,

Can someone comment on the plumbing in my basement half bath. It looks like the sink and toilet both wet vent into the main stack which drains the bathroom located directly above (all the fixtures upstairs drain to the main stack). I have included a picture. from this forum, I understand that wet venting between floors is not allowed. The toilet seems to flush OK and there are no smells coming from the sink so I think the trap is intact. Would flushing both upstairs and downstairs toilets at the same time cause problems? Would the water from the upstairs toilet block the "vent" for the basement toilet if both were flushed?
I think the plumbing upstairs is vented correctly as I can see them tying in together in the attic but it seems like there are no vents from the basement. I plan to upgrade to a full bath in the next year or so and I assume that I will need to run a dry vent from the basement through to the attic and tie it back in.

Thanks

[Master Plumber 101]

By the way it is drawn it is not correctly plumbed. If you seperate the lav from the stack and tie it into w.c. blg drain you could with appropriate sizing wet vent bathroom group. The lav eventually being your wet vent. After tee above floor ties in lav waste you can run vent to attic and tie into exsisting vent. Size's vary on what code you follow, IPC,UPC, or your own state code.

[littlebrook]

So is it OK for the toilet to be wet vented by the main stack? The distance from the toilet to the stack is about 3 feet.

[littlebrook]

Here's another picture showing the upstairs plumbing

[Master Plumber 101]

You can't wet vent sink and toilet thru stack where fixture's above drain into. You can only wet vent using the waste with 1 (DFU) or less such as lav or bar sink. You have to remove basement lav and tie into toilet bldg. drain using a wye or tee wye. Waste going to lav connection shall be a min.of 2" in dia. Exp. You would use a 2x1/1/2x1/1/2 tee. The 2" portion being the waste and the top 1/1/2 run being the vent, the 1/1/2 branch is waste to lav.Is the waste currently under the slab, can't tell by drawing.

[littlebrook]

No, the main drain exits through the foundation wall at a height of about 12 inches. There is a Hub (Wye?) connected to this that handles the basement toilet horizontally, and the main stack (and therefore upstairs bathroom) vertically. The drain through the wall is cast iron, the main stack is copper, and the line from the toilet is ABS/PVC.

[Master Plumber 101]

littlebrook, I'm not sure to exactly how this basement toilet line is set up. Is this a tri level home or is the toilet and sink built on a platform in the basement. What is throwing me off is that the waste enter's 12" off the basement floor, so how exactly is the toilet and lav sitting.

[littlebrook]

The toilet is built on a platform and is a rear-outlet that is connected to the waste line through a wye. The house is a raised ranch.

[Master Plumber 101]

You would still have to remove the lav waste and tie it in to the toilet line if you wanted to wet vent utilizing the lav as your wet vent,or tie a tee into the lav waste and install dry vent. That mean's you also have to vent the toilet seperate.

[littlebrook]

Thanks. I bought this house last year and it has been nothing but a plumbing nightmare! Looks like I'll have to include running a dry vent from the basement to the roof on my list of things to remedy. For now, the basement bathroom seems to work OK so I'll wait until the remodel to fix the venting issue (unless you think it is dangerous to have it as it is) since this is obviously a job for a qualified plumber and I can't afford one right now.

[hj]

Neither of the basement fixtures is connected or vented properly.

[littlebrook]

So if I was to add a dry vent to both the toilet and sink waste lines, it would still be wrong? The house is over 40 years old and although I think the basement bathroom was added later it is probably still at least 20 years old. It has worked OK so far.

[Master Plumber 101]

So if I was to add a dry vent to both the toilet and sink waste lines, it would still be wrong? The house is over 40 years old and although I think the basement bathroom was added later it is probably still at least 20 years old. It has worked OK so far.

I don't know what code you exactly you follow, but individually venting each fixture is certainly the safest way of venting which would be permissible by all code's. Just make sure nothing come's between your dry vent's and fixture's.

[littlebrook]

Thanks for all the advice, I'll have to call in a plumber to sort out this mess.