OSB Sheeting - Vertical or Horizontal

[mod600]

I've got a 32x64x10 pole barn I just put up this summer. Cement work is all done, time to start insulating and sheeting the walls. I will be putting up a divider wall with a service door and overhead door in it. This will allow me to roll sleds, wheelers, etch from storage side (unfinished) to the shop side (finished) Here is my plan of attack:

I will have horizontal purlins on both sides of the poles, the outer the tin is attached to and the inside will have OSB attached to. I'm planning on cutting 1-1/2" white foam to fit inside of both sets of purlins and 6-1/2" batting in between the poles, so I'll end up with a 9" thick insulated wall with an R25 value. I was planning on running my sheets of 1/2" OSB horizontal and running my purlins (2x4s) roughly every 2'. I will be running a 2x6 to mount my electrical boxes in conduit later on and one above my windows to give decent nailer to support for future shelves and/or cabinets. I was also going to cut nailers to fit in between the horizontal purlins and put them right on the poles. Poles are 8' on center, so all 4 sides of the OSB will be backed/supported by a nailer. I was going to use a full sheet at the top, one below that, and a partial sheet at the bottom (10' side walls) Figure the benches, tool boxes, equipment, etc will cover the bottom seem. Some guys run their sheets vertically, do they put in vertical nailers to support the seams, or is this not neccessary? I haven't gotten into it too far, more thinking than doing at this point. My plan in my mind makes sense...but I could be missing something...? Any thoughts and suggestions...
Thanks!
mod600

 

[Gary S]

I would try to attach the OSB so the seams of the OSB fall on the purlins. That way you have no open seams to leak air.
My garage is stick built. I put the OSB vertical on the studs. My OSB seams are sealed by the studs. If I had put it horizontal, I would have seams crossing the studs and leaking air.

 

[Falcon67]

I would try to attach the OSB so the seams of the OSB fall on the purlins. That way you have no open seams to leak air.
My garage is stick built. I put the OSB vertical on the studs. My OSB seams are sealed by the studs. If I had put it horizontal, I would have seams crossing the studs and leaking air.

Hate to tell you this, but your seams are not sealed unless you caulked them before you put up the sheets, or caulked the joints after. My OSB is screwed to the studs and joists on the ceiling. I have an exhaust fan that applies some minor pressure to the attic - every joint at every ceiling joist leaks air and all are covered with R13 batts. They don't leak very much - but sealed? No, not even.

 

[Gary S]

OK, be picky. Sealed isn't the best word. I'll say it eliminates gaps.

I still would run the OSB so the seams are on the buillding structure. You have a lot less air flow than running the seams across open space.

 

[Angelfire]

OSB should be installed with gaps between sheets. 1/8" to allow for movement during swings in humidity. Says so right on the sheets.

To get sealed, I caulked all the seams and installed an air barrier/vapor retarder. We're not done with the addition just yet but I can already tell the difference in how quiet the place is and it's inherent insulating value vs. the rest of the house.

 

[fflintstone]

I would add 1" foam board over the purlins after putting the 1 1/2 in between. Than install the OSB vertically caulking the seams. This way you put a thermal gap between the purlins and outside tin, plus add another R4 for minimal cost.

 

[awdblazer]

i put mine up vertically just cause it was easier to install

 

[c/o say]

Put mine horizontal but I held my sheets off the floor 1/4 in so they are not in contact with concrete so they can't wick any water. Put my purlins on 16 inch centers Your plan of using two by sixs where you want to hang stuff is good. I used two by eights but I had some used ones on hand. Makes it easy to know you have something solid to hang stuff from. Sounds like you have a good plan to me.

 

[mod600]

The whole shed was wrapped with house wrap before the tin was put on also. I plan to put up poly before I sheet it as well. I think I'll continue with my plan, I justed to make sure I wasn't missing anythinig.
Thanks guys!

 

[ddawg16]

Depends on if your plans call out the OSB as a shear wall.

If any section is an A or higher (B, C, D) then you can't have any unnailed edges. If you go horz, then you will have to have blocking anywhere there is a seam an nail according to the edge nailing schedule.

If no shear....put it up any way you want.

AND.....you will find out why 16" is such an important measurement.

 

[Falcon67]

OK, be picky. Sealed isn't the best word. I'll say it eliminates gaps.

Sorry - that does read real picky!

With a 10' wall, vertical would go quicker - with 10' sheets anyway.