anyone knows if termination of vent pipes under panels is allowed in California? Trying to use this method in PGE territory.
1. I recommend making sure roof condition is good for expected life of panels. if not, re-do roof first... and if I had it to do again, I'd have insisted on consolidating a number of plumbing roof vents when I had the roofing work done (would have been relatively cheap/easy with large open attic space to work in, and lift 'n 'lay involved wood replacement already).
2. not that different jurisdictions can have their own rules/interpretations regarding vent pipes and solar panels. This is NOT a PG&E question, but for your local AHJ (residential building code enforcement jurisdiction authority). And plenty of stories of building inspectors not following the rules... so ymmv.
the CA code for the top of the vent height above the roof recently (last 3 years?) decreased, in part to accommodate solar installs [from what I've read]. I used these as reference these articles from Nov '22
- https://solvoltaics.com/plumbing-vent-under-solar-panel/
- https://www.thesolarnerd.com/blog/how-to-install-solar-panels-over-plumbing-vents/ Last updated: November 14, 2022
which includes
Installing solar panels on top of plumbing vents
A plumbing vent is a small pipe that allows air to enter drain pipes or sewer gases to escape. They are small, usually between 1-1/4 to 4 inches in diameter. Local plumbing codes will dictate how high above the roof surface the vent must rise. A common requirement is that the pipe must rise six inches above the roof. For example,
California Plumbing Code section 906.1 states that “Each vent pipe or stack shall extend through its flashing and shall terminate vertically not less than 6 inches (152 mm) above the roof”.
In snowy climates, it’s common for the requirement to be six inches higher - that is, a full foot above the roof. If you happen to live in a municipality without any such code, it may be possible to install solar panels right on top of your plumbing vent. A rack of solar panels sits about 5 inches above the roof surface. Where permitted, the vent pipe can be cut down to just a few inches above the roof surface so that it can sit in the space underneath the panels.
what gets tricky is your roofing material... is Spanish S-Tile and vents come out in the valley... then distance above top of S-Tile doesn't have to be that much...