Oriented Strand Board?

Question:OSB questions?
I'm building a new 16'x20' workshop. The framing is almost complete and I'm going to install 4 x 8 x 7/16 Oriented Strand Board over the studs. Do I install it vertically(8ft up and down) or horizontally like sheetrock(8ft left to right) with the joints staggered? Also do I need to allow any spacing between the sheets for heat expansion or do I just butt the seams tightly? And what type of vapor barrier should install over the OSB if I am putting vinyl siding over it. Thank you.

Answers:
I'd install the OSB horizontally because it tends to add strength to the structure, And yes, stagger the joints to also give more strength. As far as spacing, I have never intentionally left any spacing when using OSB on sidewalls. I believe it is recommended when using as roof sheeting. Your material supplier should have some data sheets that will give manufacturer's recommendations about spacing.

Many times we will run a 1X4 around the bottom of the walls to protect the OSB from the moisture - but that is when using 3/4" OSB.

For Vapor barrier, any of the various brands of "house wrap" will work. We have used products by Tyvek, Owens Corning, Menards among others behind vinyl siding.

Now it used to be recommended to wrap the house wrap into the structure before installing your windows and doors. I believe that they now recommend wrapping the structure after all windows and doors are installed. The moisture that gets behind siding follows the house wrap that is why the change - moisture was entering the structure and rotting out Windows.

Also, don't forget to use drip cap on ALL your windows and doors to prevent water from damaging them. Some may suggest that the "J" channel is sufficient to protect them but do no take that chance.

Good luck on your project.