What is the advantage of the furring strip?
Craig writes from Canada: “I am replacing wood siding on my bungalow with vinyl. I have new windows with a vinyl open brickmold attached (to accept the vinyl siding). I have a jam depth on the window designed to allow for 1” of extruded polystyrene insulation on the outside wall. My proposed installation then would be (from inside out: • 1/2 inch drywall • 2×4 studs with batt insulation in between • 1/2 inch OSB exterior wall sheathing (all the above is existing) “I plan to add: • 1 inch extruded polystyrene ‘codeboard’ • housewrap • windows and vinyl siding “I see some mention of adding 1 inch wood furring strips over the codeboard before attaching the siding. If I do this, my siding will no longer align with the J-channel that is part of the window brickmold. It does not seem that building code in Canada requires the wood furring. My question is: what is the advantage of the furring strip and what do I give up by not having it in place? Are there any work-arounds you can think of?” A
