50: OSB Wall Sheathing

Fall is about my favorite time of the year, especially for outside work. Thinking back on previous years I’m reminded that I seem to get a lot of work done in the fall of every year. Since the torrential rains and winds of Hurricanes Gustav and Ike I’ve finished up the exterior stud walls, plumbed and lined them and now almost finished putting on the wall sheathing.

Because my wall studs are on 24” centers I opted for 5/8” OSB rather than the standard 1/2” stuff. Besides making the wall a little stiffer, I think it will help keep the walls a little flatter.

Pic 1 shows the south and a little of the east wall. My sources recommended that I cover the rimjoist and mudsill with the sheathing as that makes a much stronger wall by making the nails fail in shear (cut in half) rather than in tension (pulling them out). For this to work the sheathing has to be nailed into both the mudsill and the wall sole plate. I used about a 5” spacing on my nails; thank goodness for the nail gun as each 4x8 piece gets about 30 nails.

Pic 2 is the east wall. Because there are so many windows in this wall, I decided I’d get better strength if I ran the sheathing horizontal. If you think of the panels as being 4’ x 8’ you can see that on the east wall the top panels are up almost 18’ in the air. So, how did the boy get those panels up there (by himself).

Pic 3 is the answer to that question. I used a triangle shaped jig and a home-made block and tackle. The jig gets C-clamped to the top of the wall and there is a line that comes off the backside (tied into a floor joist) to resist the load trying to pull the jig off the wall. I came across some really good metal pulleys at the local welding supply store. Engraved into the side of each were the words, max load 685 lbs. These panels weigh about 65 lbs each, so I knew the pulleys would handle it. I started out with 3/16 polypropylene rope (rated for 75 lbs), but it was too narrow and too slippery to grab and pull, so I switched to new manila rope. My block and tackle consists of three wheels, two on top and one on bottom. By my calculations this gives me a mechanical advantage of 3, so the 65 lb OSB panels require only a 22 lb pull to lift.
Having worked professionally in the field of safety, I KNOW that you NEVER get under a suspended load…ever. So, it took a little figuring on how to get the panels raised, and then secured before nailing. Hint: Once you raise them, and tie off the line, then go inside the building to do final positioning. If a rope breaks, you’re safely out of the way.