Sewer Ventilation

[Anonymous]

I recently had a bathroom installed in my basement. We are down to the final stages, one of which being tying the sewer ventilation for this bath into one of the stacks. The bathroom is situated in an area where there is no easy answer as far as getting to the closest available existing stack. If we don't vent it out one of the existing stacks which come out the roof on the back side of the house, we would have to run it out the roof from the front of the house, which I would rather avoid. One option was to tie it into one of the two existing stacks which would, in either case, involve cutting into one of the walls upstairs, etc.

The contractor suggested a self-ventilating attachment. I really don't know more than that at this time, but I did ask if it was code and if it would ensure no odors and I was told 'yes' on both counts. Have you ever heard of some sort of self-ventilation attachment? If so, are they code and are they effective? I would guess that this would ventilate into an adjoining basement storage area.

THANKS!

[Wgoodrich]

What you are talking about is an air admittance valve. This allows air to enter the drain to relieve any pneumatic action that will suck your traps dry. They are allowed on a branch drain circuit as you are discribing. This will be a vent stack coming up above the highest outlet into the drain. Then the air admintance valve is installed there on the end of that pipe. The air admittance valve is a rubber flapper designed to keep sewer fumes from leaving the vent but allowing room air to enter the drain to stop sucking the drain traps dry. Acts like a check valve. Many do not like the use of these air admintance valves but they are commonly used expecially in existing homes to avoid damaging finished walls etc. to get a vent stack out the roof to the outside. Kind of the lesser of two evils. Either the air admittance valve or open up some walls.

Hope this helps

Wg

[Anonymous]

Thanks for the quick response!

Well, so I guess what you're saying is, he can vent it into the basement storage area adjoining the bath as long as the outlet is above the highest drain in the basement (the bath sink, in this case).

Also, is his way of venting it something you would recommend? Is it something that would typically pass an inspection?

[Wgoodrich]

The International Residential Code recognizes these air admittance valves to be used as a venting form.

Good Luck

Wg