I am resheathing my 2 story 2x4 construction 1974 residential home prior to applying vinyl siding. The sheathing is currently a 5/8 to 3/4" gypsum black paper exterior grade product. I am not removing this, but going over top with a 1/2" EXTERIOR GRADE 4 PLY PLYWOOD and a TYVEK BARRIER. There is no concern regarding wall depth as I am installing new construction windows as well. All product is on site and ready. I initially purchased bostitch 2 3/8" ring shank galvanized S8DRGAL-FH, but don't think they are long enough. Do I need th 10d's 3"? Since the total sheathing depth will now be 1 1/8" to 1 1/4"
i would definitely go to the longer nails. reason being the gypsom product has zero holding power for the fastener it just acts as a spacer which reduces how deep into the stud the nail penetrates. also it creates a potential for shear sag which is when the weight of the sheathing can cause the nails to bend and the sheathing will sag. . similarly youll want to be using longer nails when you go to hang the windows by nailing through the nailing flange and with the vinyl siding. 2 1/2" siding nails will work for that.