Ledger Board For Porch Roof With Exterior Insulation – GreenBuildingAdvisor

I’ve been looking for answers on this forum and have come across a few solutions but not really any that fit my exact situation. We are planning to have a porch off of our house. I was hoping to attach the ledger board for the porch roof to the house, into the 2nd floor studs, not the rim board because the porch roof would end up too low.

We have two layers of 1.5in polyiso to make up 3in of exterior insulation in the house. Originally I was thinking I would remove one layer of the insulation and attach a 2×6 ledger board which would be flush with the outer layer of foam, but it seems like attaching the ledger through 1.5in of foam is probably not a great idea. I would like to reduce thermal bridging so I don’t really want to cut the foam all the way back to the sheathing for the ledger.

I was looking at the Maine deck brackets but it seems like those are for use in a rim board? I guess I could add blocking to the wall on the interior if I went with those but then the weight of porch roof would be on the sheathing, would that be a problem? 

We are still figuring out how we’ll anchor the supporting posts, too. Either thinking of pouring sonotubes or using some kind of ground anchors but need something that can stand up to the frequent strong winds. 

Any advice on what to do here would be greatly appreciated!