[67drake]

I’m going to be plumbing an entire project house of mine. I’m considering using air admittance valves as opposed to regular venting for the pipes. Main reason is fewer holes in the roof,BUT I’ve never used these before.
Anybody use these before? Pros and cons?
Thanks

[dataway]

Check your local codes, there are some restrictions on where they can be used. For instance in most cases they can't be installed in walls or inaccessible areas.

I've got a couple installed that way that I'm going to have to fix when I redo the bathroom this winter. Another thing to consider is that after they age a bit they can tend to cause "gurgling" when the water drains as the mechanism gets sticky with age.

Although I installed mine 25 years ago and probably used the cheapest thing I could find (same reason as you, wanted to limit roof penetration in this snowy climate). Good chance there are better options that what I used this far down the road.

Codes could also have changed since I installed mine .... I'm still up in the air about whether to use air valves in the attic, or vent through the roof. Our main drain line has the large code require vent through the roof, I used these valve in another part of the house with a different roof structure.

PS. After some research I realize I probably used the older Automatic Air Vents ... which are no longer code in most places. Appears that codes are far more accepting of the Air Admittance Valves.

[tooski]

I have used some. No problems. Works like a check valve. Allows air in, closes if water reaches it. In my research, codes do not allow them. When installed they must be higher than the highest level of water attained in a fixture in the building. I just install it higher than the fixture it is venting. In my home, I just have one vent through the roof. All of the vents are tied into that in the attic.

[67drake]

Thanks guys.
I checked with a local plumber friend of mine and he said they meet code in my area if installed properly