Use of AAVs and other creative venting in steel building

[viper1]

Doing a personal 2 story office space in a residential shop. The core issue is I would prefer not to shoot a vent through my steel roof. I realize some can sneak a side wall vent out there, but that is 30ft away, with no wall structure to get it there.

the basic layout is 60x100 building, and one end, 30x60 area becomes the office space with some bonus area up top. Plumbing will be right smack in the middle of that built space. The bottom gets a small kitchen, 1/2ba, and wash basin on other side of wall. I am strategically placing upstairs plumbing in the same spot so they can share (simplify the plumbing). Upstairs gets a full bath and another small kitchen.

Regardless of any application of AAVs here, I still need a fresh air vent for pressure situations? Any other remedy someone can think of?

 

[Reach4]

KS uses IPC, so AAVs are allowed.

If you had a sealed plumbing sewage/grinder pump, you would need a roof vent, but if you are feeding to the septic/sewer by gravity, you don't need to worry about pressure building up.

 

[Sponsor]

 

[viper1]

KS uses IPC, so AAVs are allowed.

If you had a sealed plumbing sewage/grinder pump, you would need a roof vent, but if you are feeding to the septic/sewer by gravity, you don't need to worry about pressure building up.

Thanks, I didn't even check the book as an open vent just seems obvious. My only experience with AAVs is small 1/2ba applications and RV stuff. I guess I need to see if I can get away with a single AAV or need mutiple. My thought was a single device to service in a convenient location. However, my brain starts to think about redundancy and what could happen. Upper floor toilet flush, AAV fails to open, pressure spike on main level.

 

[Reach4]

I see your point. An AAV should not open because of pressure. So if a big chunk of water flows, how does the pressure get relieved? I guess air can come back up thru the 3 inch pipe, and squirt some air back through the toilet bowl before the trap refills.

 

[wwhitney]

KS uses IPC, so AAVs are allowed.

Yes, but at least one vent to outside is required. IPC 918 is AAVs, and 918.7 says "Within each plumbing system, not less than one stack vent or vent stack shall extend outdoors to the open air."

The only possible leeway I see is that "plumbing system" can mean all the plumbing on a single premises, as opposed to just a single building. So if a second building on the same sewer connection has a vent through the roof, you could argue that satisfies 918.7, and just use AAVs in your building. Not sure if that would fly with an AHJ, but it seems somewhat reasonable.

Cheers, Wayne

 

[Sylvan]

KS uses IPC, so AAVs are allowed.

If you had a sealed plumbing sewage/grinder pump, you would need a roof vent, but if you are feeding to the septic/sewer by gravity, you don't need to worry about pressure building up.

NYC uses IPC, and AAV is NOT legal. (Rightfully so)

 

[Jeff H Young]

Im a plumber so id be ok with a great building and a great plumbing system rather than a not so good or to code plumbing system and a slightly better roof

 

[All Shore Plumbing NY]

Doing a personal 2 story office space in a residential shop. The core issue is I would prefer not to shoot a vent through my steel roof. I realize some can sneak a side wall vent out there, but that is 30ft away, with no wall structure to get it there.

the basic layout is 60x100 building, and one end, 30x60 area becomes the office space with some bonus area up top. Plumbing will be right smack in the middle of that built space. The bottom gets a small kitchen, 1/2ba, and wash basin on other side of wall. I am strategically placing upstairs plumbing in the same spot so they can share (simplify the plumbing). Upstairs gets a full bath and another small kitchen.

Regardless of any application of AAVs here, I still need a fresh air vent for pressure situations? Any other remedy someone can think of?

AAVs can work here but you'll still need at least one true vent to outside since AAVs only let air in they don't relieve positive pressure.With all your plumbing stacked in the middle, that actually simplifies things quite a bit. One roof or sidewall penetration can handle the main venting requirement, then AAVs can support the rest.
Steel buildings always seem to turn simple venting into a geometry problem.

 

[All Shore Plumbing NY]

Yes, but at least one vent to outside is required. IPC 918 is AAVs, and 918.7 says "Within each plumbing system, not less than one stack vent or vent stack shall extend outdoors to the open air."

The only possible leeway I see is that "plumbing system" can mean all the plumbing on a single premises, as opposed to just a single building. So if a second building on the same sewer connection has a vent through the roof, you could argue that satisfies 918.7, and just use AAVs in your building. Not sure if that would fly with an AHJ, but it seems somewhat reasonable.

Cheers, Wayne

With your plumbing all grouped together, one well-placed vent plus AAVs is probably the cleanest setup here.