Your thoughts on an Air Admittance Valve (AAV)?
My contractor installed an air admittance valve (AAV) for the main sink and dishwasher in my kitchen b/c we've moved the main sink to an area where there's only a half wall and is open to the family room on the other side. It's not an island - but for the purposes of this discussion, it's the same as an island configuration.
The closest vent stacks are quite a bit away and require a lot of breaking through floors and concrete. My contractor insists that AAV is the way to go and it's rated for 20 years. What do you guys think? We are located in Maryland - and I tried to look this up for plumbing code and can't tell.