How do I attach the windows to the house if I use 1" Styrofoam on the outside of thse 1/2 cdx plywood sheathing to make it air tight? do i attach the window to the cdx and put butt Styrofoam ot it. Do I add a 1x3 as a nailer,etc? To cut cost i want to Sheetrock return to the window inside. No trim. Any illustration?
Thanks
For others information to help answer your question, what type of exterior siding were you planning - and are you planning to put 3/8 lath or something over the foam to allow drainage (screen wall) so thour siding will not develop mold problems.
Here I have seen windows under the foam - the foam carved down with a knife then stucco sprayed over the entire house in tract home projects. That probably doesn't apply to your project though.
T-11 with stainless steel nails to prevent rust.
Were you doing the screenwall to get the T1-11 off of the foam? The foam can be a moisture barrier if I recall correctly with taped edges but capillary action can hold and spread water behind your T1-11 causing rot. The 3/8 space promotes drainage at the gaps where the sheets join or through gaps in the end of the spacers allowing the backside to dry.
I put a layer of rubber flashing tape on the sill, then I put a bead of caulk on the rough opening right over the foam. Then I put the window in, compressing the caulk. I put tape over the nailing flange next. Right over all of that is my vinyl siding. No space, but vinyl just hangs so there should be a lot of air in there. I did caulk all my foam seams too. I don't expect problems.