Google "island loop vent". It's legal in all 50 states. Some locations also allow Studor vents. Your plumber will have the information necessary.

Slab in MN? Um, how thick is this concrete? Slabs have to have footers that go below the frost level. By the time you've done that, you've just about gotten deep enough for a basement, which is why most houses there have them. It makes no sense to go through the excavation and insulation and then do a slab.

I must clarify...yes we will have footings...so not just a slab. Thats just how we refer to it up north here! And we won't have a basement because it's too risky here in the red river valley...basements are notorious for getting wet. Plus, we will retire in this home and we do not want any steps. With a basement up here there would be a couple steps to get into the house. And when we are old we don't want to have to worry about going to the basement. We will have a heated floor this way too...will keep us nice and toasty in the wintertime!

Nikkidan,

Below is a link to the text of the Minnesota Plumbing Code. You can Island vent, Studor vents are not approved for use in Minnesota. If you need a diagram for Island venting, I can email you one. Once on the link, click on the PDF link to see all sections at once.

Hope This Helps,

Dan

Here is a link that might be useful: Minnesota Plumbing Code