Cost to combine plumbing vents

[adaboost]

Hi all,

Trying to understand costs of moving PVC plumbing vent stacks. We recently got a quote to the tune of ~$400 for each vent moved, and another $400 on top for a new roof vent (i.e. we are moving all 3 into a new single vent). All vents are accessible and clearly visible from the attic and are within ~10 feet of each other. This does not include any roof patching.

Wondering if this is reasonable (location: bay area), and/or if folks have a recommended company that does just vent moving & patching in prep for cleaner solar installs?

Thanks!

 

[BGbreeder]

Sounds reasonable to me, especially if you have priced large PVC lately, $2/ft, plus $20 per elbow or Tee.

Depending on where you live, these may be permissible;
https://www.lowes.com/pd/Oatey-1-1-2-in-Plastic-Mechanical-Plumbing-Air-Admittance-Vent/1000363773
I am not endorsing them, just pointing out an option.

All the best,

BG

 

[wwhitney]

Depending on where you live, these may be permissible;

Not in California.

I can tell you how to do the DWV plumbing but I have no idea how much a plumber would charge.

Cheers, Wayne

 

[arnolddeleon]

Hi all,

Trying to understand costs of moving PVC plumbing vent stacks. We recently got a quote to the tune of ~$400 for each vent moved, and another $400 on top for a new roof vent (i.e. we are moving all 3 into a new single vent). All vents are accessible and clearly visible from the attic and are within ~10 feet of each other. This does not include any roof patching.

Wondering if this is reasonable (location: bay area), and/or if folks have a recommended company that does just vent moving & patching in prep for cleaner solar installs?

Thanks!

My rule of thumb is roughly $200/hour for a plumber the SF Bay Area. Does that include the roof patch for the removed vent? I think I paid my roofer between $100 and $200 per vent for removing/patching abandoned vents on my roof. I had replaced gas furnace and water heater with heat pump versions.

 

[adaboost]

It doesn't include the cost of patching the roof unfortunately, so it seemed kind of high - i.e. total cost probably will end up being 2-2.5k to move 3 vents which seemed on the very high side.

We found a highly-rated roofer on Thumbtack who is able to do light plumbing to combine the vent stacks to a new vent. Tentatively scheduled and will report back here how it goes. We contacted 3 other roofers who declined, surprised that this isn't a service that more people are willing to do since folks are going solar.

 

[wwhitney]

We found a highly-rated roofer on Thumbtack who is able to do light plumbing to combine the vent stacks to a new vent. Tentatively scheduled and will report back here how it goes.

If you want advice on how it should be done, or criticism of how it was done, post some before, or after, pictures here.

One thing to know is that the CA Plumbing Code (based on UPC) requires a minimum aggregate area of all the roof vents. If you have 3 or fewer toilets, the minimum is the equivalent of one 3" roof vent. [Starting January 1, 2023, when CA switches to the latest code based on the 2021 UPC, 3 toilets changes to 5 toilets, as the plumbing code slowly catches up to lower flow toilets.] If it's 4 or more, it's the equivalent of a 4" roof vent.

So how many toilets you have, and what other plumbing roof vents you may or may not have, will determine the minimum size of the combined vent.

Cheers, Wayne

 

[jboy210]

...

We found a highly-rated roofer on Thumbtack who is able to do light plumbing to combine the vent stacks to a new vent. Tentatively scheduled and will report back here how it goes. We contacted 3 other roofers who declined, surprised that this isn't a service that more people are willing to do since folks are going solar.

I would guess that some plumbers don't want to do minor work. A few hours billable work with driving time can cost them a lot if it takes away from their potentially more lucrative jobs like redoing an entire kitchen and/or bathroom for a full day.

 

[adaboost]

If you want advice on how it should be done, or criticism of how it was done, post some before, or after, pictures here.

One thing to know is that the CA Plumbing Code (based on UPC) requires a minimum aggregate area of all the roof vents. If you have 3 or fewer toilets, the minimum is the equivalent of one 3" roof vent. [Starting January 1, 2023, when CA switches to the latest code based on the 2021 UPC, 3 toilets changes to 5 toilets, as the plumbing code slowly catches up to lower flow toilets.] If it's 4 or more, it's the equivalent of a 4" roof vent.

So how many toilets you have, and what other plumbing roof vents you may or may not have, will determine the minimum size of the combined vent.

Cheers, Wayne

Thanks this is helpful! I spent a few minutes looking at the CA code: Searchable platform for building codes

Seems like we have 20 fixture units on this branch (3x toilets at 3.0 each + 1x washer at 3.0 + 1x laundry sink at 2.0 + 2x bathroom sinks at 1.0 + 2x bathtub at 2.0) which is below the 2" (24 units) limit? Just wanted to confirm as the roofer said they'll upsize to 2" but we can ask for 3" if it makes sense.

 

[wwhitney]

Thanks this is helpful! I spent a few minutes looking at the CA code: Searchable platform for building codes

Seems like we have 20 fixture units on this branch (3x toilets at 3.0 each + 1x washer at 3.0 + 1x laundry sink at 2.0 + 2x bathroom sinks at 1.0 + 2x bathtub at 2.0) which is below the 2" (24 units) limit? Just wanted to confirm as the roofer said they'll upsize to 2" but we can ask for 3" if it makes sense.

That's fine for the branch, but how many toilets are there in the house as a whole, and what other vents through the roof are there besides the 3 you are combining?

Cheers, Wayne

 

[adaboost]

That's fine for the branch, but how many toilets are there in the house as a whole, and what other vents through the roof are there besides the 3 you are combining?

Cheers, Wayne

Only 3 toilets :*( The other fixtures have their own dedicated vents that aren't in the way of the panels

 

[wwhitney]

Only 3 toilets :*( The other fixtures have their own dedicated vents that aren't in the way of the panels

OK, but you need to specify how many other DWV vents and what sizes they are. To check whether a single 2" vent plus those other vents will be at least as large as a 3" vent.

1 other vent: either it or this combined vent has to be 3".
2 other vents: if they are both 1.5", then this combined vent has to be 3". If at least one is 2" or larger, then the combined vent can be 2".
3 or more other vents: the combined vent can be 2".

Cheers, Wayne

 

[adaboost]

As an update, we went ahead and combined the vents to a single new 3" (thanks Wayne!) and submitted for a redesign to Tesla. They got back to us in 3 days approving the design change and adding ~10% more panels and sent us an updated contract.

Fast forward to today, for our scheduled MPU install (arrival window 7:15-9:15am) and Tesla and/or their sub is a no-show. Wait times for their 877-961-7652 phone number are 55 minutes +, so we're waiting for a callback to see if we still have to be on standby (since 7am) to wait for someone to show up for their estimated 4-8 hour MPU replacement job.

Good thing I took a day off to standby