DavidTu
Member
In a moment of hubris , I had two 2" VTR roof jacks installed for a 3" drain. <doh!
[Mea culpa: I am aware of the area requirements for VTR but I didn't have my book or calculator with me and I knew that two 3" pipes > 1 4" pipe, and same is true for all other pipe sizes relative to the next size up so I errantly ASSUMED that the same held true for two 2" > one 3" in area.... EXCEPT, it turns out it's not: 2x2" = 6.28si vs 3" = 7.06si).]
My venting is mainly all 2" runs. I'm in Seattle and the Chief Inspector has previously told me that they do NOT require a continous run from the sewer through the roof at full-size of the sewer (ie. 3" from sewer through roof). Rather, as long as each fixture is appropriately vented and as long as the accumulated dfu's are within spec all is good (provided we meet the area requirement which we did not do).
My question is: a) will the inspector definitely require me to upsize one VTR to 3" (leaving other 2")? ... i.e. should I see if it sneaks by or just go ahead and do it now! and (b) is there any real-world benefit to doing this inasmuch as venting to satisfy the dfu's is easily handled by 2" vent pipe (24 dfu capacity, 13 used) and really all that will happen is in the attic I'll upsize the 2" pipe to 3" when I join a couple of 2" pipes there. NOTE: I do plan to use a AAV for kitchen sink.
FYI: one 2" VTR is serving a toilet + lavatory (4 dfu), the other is serving laundry tray & clothes washer standpipe, toilet, lavatory, tub/shower, and a kitchen sink w/ disposal + dishwasher vented on AAV (13 dfu including KS)
[Mea culpa: I am aware of the area requirements for VTR but I didn't have my book or calculator with me and I knew that two 3" pipes > 1 4" pipe, and same is true for all other pipe sizes relative to the next size up so I errantly ASSUMED that the same held true for two 2" > one 3" in area.... EXCEPT, it turns out it's not: 2x2" = 6.28si vs 3" = 7.06si).]
My venting is mainly all 2" runs. I'm in Seattle and the Chief Inspector has previously told me that they do NOT require a continous run from the sewer through the roof at full-size of the sewer (ie. 3" from sewer through roof). Rather, as long as each fixture is appropriately vented and as long as the accumulated dfu's are within spec all is good (provided we meet the area requirement which we did not do).
My question is: a) will the inspector definitely require me to upsize one VTR to 3" (leaving other 2")? ... i.e. should I see if it sneaks by or just go ahead and do it now! and (b) is there any real-world benefit to doing this inasmuch as venting to satisfy the dfu's is easily handled by 2" vent pipe (24 dfu capacity, 13 used) and really all that will happen is in the attic I'll upsize the 2" pipe to 3" when I join a couple of 2" pipes there. NOTE: I do plan to use a AAV for kitchen sink.
FYI: one 2" VTR is serving a toilet + lavatory (4 dfu), the other is serving laundry tray & clothes washer standpipe, toilet, lavatory, tub/shower, and a kitchen sink w/ disposal + dishwasher vented on AAV (13 dfu including KS)