View Full Version : adding toilets to existing vent stack
01-28-2012, 10:53 AM
We are remodelling, actually we have added a first and second floor to an existing basement. There was never a first floor on the property, the house was only a basement, built in the 70's, never finished for whatever reason, it sat 3' out of the ground and 6ft in the ground, built with military grade concrete. The "basement" is totally finished, has 3 bedrooms, living, dining, kitchen and bathroom with one toilet. This is a rural property. It has a septic system fed from the house with a 4" PVC pipe. We have had the septic dug up and all is now well with that system. So now we have added a main floor and a second floor loft. We are doing this almost entirely ourself. The main sewer pipe enters the building in the basement toilet and the existing basement toilet is fed into it, and then the pipe continues up through the roof. At some point the 4" pipe transitions to a 3" pipe which we have yet to discover where. What we have now is the 3" vent pipe going up through the main 1st floor and we have temporarily passed it through the wall to the outside. What we planned to do was to use this stack to connect 2 toilets on the first floor, and one 2nd floor toilet, then continue the stack through the new roof as a vent. After reading some similar posts here, I get the impression that this is not the way to do this. Will we need to create a whole new stack from the septic to feed the new floors? Is there any way around this? The idea of busting through the 9" concrete basement floor and digging a new channel to the septic is daunting.Thanks
01-28-2012, 05:29 PM
Once a pipe is configured as a vent, it cannot become a drain without reconfiguration. You can connect other vents to this line to minimize roof penetrations, though. You can run a new line out into the yard to connect to the line to the septic tank, though, so you don't necessarily have to go through the floor - you might be able to go out the wall below the frost line and trench to the existing line - it doesn't need to be a home run on its own. It's hard to guide you without being there. You might want to pay a plumber for a consult, even if you're doing it yourself.
01-28-2012, 07:00 PM
Thanks for your reply jim.
We have been researching this issue all day and we realize now that we must supply a new waste line for the upper floors. Also we may be able to tee off the DRY vent line for venting the upper floors. Your suggestion of going through the wall below the frost line is also doable.
As for paying a plumber? oh that we could but there are none within 50 miles and all of them are too busy (their excuses). Funny thing is when we tell them no hurry, when will you be free? .... they don't know. So we say well .. a month ... 2 months? .. maybe is the reply. Seriously not one will ever show even when we tell them money is not an issue. Hard to believe, I know. We currently have a brand new furnace sitting in our living room, been there since last november and we cant find one hvac person to come install it. I guess they just dont like it when people DIY their own house.
01-28-2012, 08:18 PM
There's always the issue with assignment of responsibility when parts are supplied by the homeowner and installed by the pro...who is responsible if something doesn't work? Is it the parts supplied? Is it the labor? Is it the design? A lot of guys don't want the hassles. Also, they can often get the same part for less, then sell it to you for the same price you may get, and that becomes part of their profit. Then, being probably at least an hour each way, even a 5-minute service call wastes at least a couple of hours, and that costs as well. Can't make money while on the road - so your service call tends to be much more expensive than if you lived in town.
01-28-2012, 08:50 PM
as you say .. "much more expensive" .. except for one detail .. we are not asking how much ! I guess you would have to live here to understand .. Thanks again
01-29-2012, 08:56 PM
You need to do what everyone does. Plumb the upstairs fixtures and tie in the waste line after the basement fixtures.
The basement plumbing is being vented through the roof, and that needs to continue up through the "roof" and nothing attached to it except other "vents".
You think 9" of concrete is daunting? Try living in a home with the plumbing backing up and performing like crud.
Just because I have a car in the driveway, that doesn't mean I can fly to California in it.
One pipe is a vent. It's a pipe filled with air and sewer gas from your septic tank; which you will want to vent through the roof or the stink will wind up coming through your open windows in the Summer.
I stayed at a hotel in Belize that was plumbed with vents daylighting below the windows. It was pretty bad, but only $27.00 a night. I couldn't drink the water, and the first floor wasn't being rented because the septic was higher than the plumbing and all backed up. It didn't say those wonderful things in the online brochure.
And one pipe carries waste. The waste line needs sweeping bends, not vent 90's that would pack up and stop flowing. It needs to smoothly flow toward your septic system, or you will be calling in mystified plumbers that can't understand why their snakes are getting caught in your pipes.
02-21-2012, 07:00 PM
Terry, sorry to hijack this thread. Could you redo this diagram as if you had two 3 piece baths side by side with a common water wall. My crawlspace drain is 14 feet long ( horizontal 4 inch ) above the surface then it nosedives (with a couple of elbows )below the surface and out to the street. I just need some ideas as to how to do the waste & vent properly. Should I be connecting every fixture into the horizontal run and vent them similar to what you show here.