Using an abandoned water heater vent for my plumbing stack

[Hyrax123]

I'm installing a mother-in-law suite in a basement. We can't tie into the main vent stack (we can't connect it high enough up). So the current plans were to find a run all the way up the third-floor. This is… well, it's a long way from the basement to the past the 3rd floor.

I had a gas water heater with a 4" possibly aluminum stack that runs up to and out chimney. It's no longer used.

I'll be tying in three sinks (kitchen, bathroom, and utility sink), a bathtub, a washer, a tub, a toilet, and a dishwasher.

Can I use that stack for venting the plumbing?

 

[WorthFlorida]

If it is a abandoned steel chimney of sorts? Are all of these fixtures in the basement?

 

[Sponsor]

 

[Jeff H Young]

I assume your talking about dropping dwv pipe thru the inside of the abandoned water heater vent. only problem with that is code requires support on each floor. but I think if you support it with a risor clamp at basement and support it again at attic youll be ok but . I couldnt argue that its legal.

 

[Hyrax123]

I assume your talking about dropping dwv pipe thru the inside of the abandoned water heater vent. only problem with that is code requires support on each floor. but I think if you support it with a risor clamp at basement and support it again at attic youll be ok but . I couldnt argue that its legal.

Yeah, I'm not sure how we'd get DWV pipe that long into the chimney -- but I think all-in-all that'll be easier than finding new routing from the basement up past a bunch of eaves, etc. We'll see what they think

 

[Bannerman]

I'm not sure how we'd get DWV pipe that long into the chimney

You likely could only install downward from the top, gluing each section as it is added into the chaseway which is what your chimney will become.

 

[Plumber69]

I would think the joints would pull apart

 

[Jeff H Young]

you could push it up from bottom 8 foot at a time

 

[JohnnyCom]

Or drill a small hole near the bottom of the first pipe and attach a paracord or other small rope to support the stack as you lower it section by section. Then remove the cord after the pipe is supported otherwise from below.

 

[Jeff H Young]

Or drill a small hole near the bottom of the first pipe and attach a paracord or other small rope to support the stack as you lower it section by section. Then remove the cord after the pipe is supported otherwise from below.

There's a good way! I wasent planning on going on roof , could be steep, poor condition, no idea what he wants to do up top, I would flash the vent where it passes to open air so water cant leak around it .
Personaly I avoid roofs most of time , especialy if he is going to have a roofer on site. 2 or 3 stories up , Id be discussing it with owner because a steep roof and 3 story be talking about more money.