How high should the plumbing vents be above there roof? I have a main vent and a sink vent and both are only 6" high above the roof. The slope is about 4" high for every 12" horizontal.

Thanks

John G.

A vent stack is not like a chimney which requires 2' higher than any roof within 10'. The 6" you describe should be just fine. You are letting air into the plumbing system of the house. Do you get snow and/or snow drifts in your area, this may change my answer.

In my area we install vents 12" above roof.

The problem I'm having (on a septic system) is that one can smell the septic fumes. This has been on-going. The tank is pumped every 3-4 years and seems fine. Was just pumped 2 months ago. Now with cold weather, the smell is more noticeable.

We install our roof vents 6 to 8 inches above the roof line. For those stinky vents consider installing Odor Hog Vent Caps, (see image) on the roof vents. Good luck, Tom

All household plumbing systems need to be vented, especially on a septic field. Tom gave you some good advice but before you try one of those tell us if your vent is on the windword or leeword side of your roof line.

The main vent is on the more windward side (facing south); the sink vent is on the more leeward side (facing North); quite often the wind will blow parallel to the ridge (east-west), mainly from the west. Most of the smell seems to come on the leeward side on the east end of the house.