additional vent needed?

hello there,

my house (built in 1953) has all plumbing fixtures on the same floor. The drawing above shows the dwv system. There is one 3" vent through the roof. While I have my laundry room ripped apart, I am wondering if i need to include additional venting for the clothes washer and kitchen sink which are on the opposite end of the house from the bathroom and vent (about 25-35 ft).

Unfortunately the kitchen sink is on an exterior wall underneath a large window, and the nearest place to add anything would be about 10-15ft away. I am really hoping to avoid that.

I don't notice any drainage issues with the current plumbing, but, since my home inspector made a comment in ins report about the kitchen sink not being vented, i don't want to have to rip everything apart again if i sell the house in a few years because something is not vented properly.

let me know if i need to provide any more information. Thank you!

Jamie

If you're drawing is accurate then your kitchen sink, washer, and bath-tub aren't vented correctly.

lovely, isn't it? since i have no problems and the CO inspector didn't say anything when i bought the house, i wonder if i should just leave it the way it is. Thoughts?

jbitt said:

lovely, isn't it? since i have no problems and the CO inspector didn't say anything when i bought the house, i wonder if i should just leave it the way it is. Thoughts?

Click to expand...

Inspectors report what they can see...and they have very poor eyesight! They are not able to comment usually on issues like the plumbing vents, because you can't see any of that. l in fact, do you know FOR SURE that the kitchen and laundry are not vented somehow?

i do, jimbo. and they are not i have torn down almost every single wall in this house, so i know exactly what is and isn't there at this point. also, the crawl space and attic are very spacious, giving me and anyone else easy access for visual inspections. the laundry venting is an easy fix for me, but the kitchen is another story. i suppose it could do something like this (see picture below). i have to double check, but i don't believe we have anything that says aav are not acceptable.
The minimum kitchen waste is 2-0" on the vertical and the horizontal. You can have a 1-1/2" trap arm and vent, but the pipe after the vent needs to be 2-0"
The santee should be a 2.0x1.5"x1.5"

If the home was built in the early 50's, that explains the undersizing.

If all of the walls are open why use an AAV?

Can you not move the vertical drain/new-vent over to the left or right of the window and use a longer trap arm?

all of the walls are closed up now with exception of the laundry room. it's not an issue of opening walls, but running the 1.5" pipe through the exterior walls that do not have any doubled studs (max hole size is 1-3/8", correct?). also, the nearest place for a vertical pipe is over 60" away. trap arm cannot be more than 42" for 1.5" and 60" for 2" pipe as i recall.

quote; Can you not move the vertical drain/new-vent over to the left or right of the window and use a longer trap arm?

it would be less work to just come off the top of the drain's tee and then offset horizontally beneath the window. The same amount of drilling, but less pipework.

hj said:

quote; Can you not move the vertical drain/new-vent over to the left or right of the window and use a longer trap arm?

it would be less work to just come off the top of the drain's tee and then offset horizontally beneath the window. The same amount of drilling, but less pipework.

Click to expand...

That sounds reasonable, depending on the height of the bottom of the window.

Either way would work and I would prefer not to use an AAV.