Wall thickness

RickT

I'm having my house resided, and I'm installing new windows before the new Tyvek and siding go up. I have 2x4 walls, which should be 4 9/16" thick (1/2" drywall + 3 7/16" stud + 5/8" sheathing). But my wall is 4 15/16" thick (1/2" drywall + 3 7/16" stud + 1" foam board). My Andersen windows, built for a 4 9/16" thick wall are now 3/8" shy of the inside drywall. What's the best thing to do now? Should I have my siding contractor replace my 1" foam board with 5/8" foam board? Should I rip a 3/8" strip of pine on my table saw and extend the windows so they're flush with the drywall? Any other options?
Thanks so much,
Rick

Darylh

Reduce the thickness behind the window flange so its even with your drywall, install window then add a shimn on the outside of the window flange to bring it even with the outside foam board so everything is even. The problem with adding to the the inside window liners is trying to hide the joint, if you can this is a good way to do it. I personaly have not seen windows fastend to foam board, there has always been solid backing behind the window flange

RickT

Thanks, Daryl. Being a woodworker, I couldn't resist making trim extensions on the inside. I ripped 1/2" wide x 3/8" thick (the amount needed to extend the window jamb) on my table saw and then used my brad nailer to fasten them to the jamb. I set the trim pieces I made back for a 5/16" reveal, so they look just like a natural part of the window. LOML and I believe they actually improve the look. And the windows are now flush with the drywall, so I can continue adding casings.

By the way, my wife (LOML) and I took our kids on an Alaskan inside passage cruise 2 years ago, and we spend a week in BC. We visited the Butchart Gardens and loved it.

Thanks again,
Rick