Thursday, November 13, 2014

Barn: progress report...

Barn: progress report...  The siding crew has completely finished all the siding on the first floor, and have installed the soffits on the first floor roof.  They just left a little while ago, looking mighty cold.  Two of the builders were here today installing sheathing on the ceiling in the garage section, which they have now finished (photo).

The original plan was to sheath the interior walls and ceiling with 1/2" plywood.  Jim J., my builder, rather gently persuaded me to use what I called “chipboard” instead.  He did it by giving me an education on the differences between chipboard and oriented-strand board (OSB), which was an area that I knew absolutely nothing about.  It turns out there's a big difference between the two.  Chipboard is practically obsolete these days.  It was made by pressing wood chips, randomly oriented, together with glue and resin.  It wasn't very strong, and the glues used were inferior.  It's main claim to fame was that it was cheap.  OSB is made in a much different way, with longer, thinner purpose-cut chips that are carefully oriented in the manufacturing process to provide high strength in all directions, and a higher strength in one particular direction.  The glues, resins, and waxes used to bond it all together in a hot press are far superior to what they used for chipboard.  The result is actually stronger than plywood, mainly because OSB contains no interior voids (all but aircraft grade plywood does).  The particular OSB we're using for sheathing has one smooth side (you can see the reflection in the photo) that's smoother than the A side of plywood, ready for paint with no sanding required.  It's really kind of amazing how much better materials are available these days...

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