I'm starting to get my ducks in a row for re-shingling the outside walls of my house with cedar shingles like what was on it originally and I'm having a hard time understanding what this business of "house wrap" that seems to be all the rage nowadays is about, when for probably over a century tar paper (some would call it building felt or felt underlayment) was used to cover every house's sheathing and it worked just fine. The spiel seems to be house wrap offers wind and moisture resistance, but isn't that the main reason why we put siding on our houses? If house wrap is so great why isn't it commonly used on the roof also because the roof is just as susceptible to moisture and wind infiltration. I'm thinking if people are putting house wrap under their siding for wind and moisture resistance they must not have a lot of confidence in their siding, and they are being suckered into using an expensive material unnecessarily. To me it seems like the most important thing would be to get whatever underlayment you use on the side of you house covered up in a timely manner and not expecting it to BE your siding indefinitely. I could understand plastic siding not offering much in the way of protection for a house's exterior walls, but several layers of cedar shingles (the way shingles are typically installed) with properly staggered joints seems like it would be impervious to about anything mother nature could dish out.