Calling all builders!

[Dennis McCullen]

OK this is elementary - but I'm not finding any answers online b/c it's so simple???? Or is it? When sheathing a stud-framed structure with either OSB or plywood, it is said you can choose to apply sheathing either vertically or horizontally. Let's say I go vertically. If I leave the recommended spacing of 1/8" between sheets for expansion due to moisture, it seems to me I am quickly leaving the center of the stud where the two sheets are supposed to meet. When I put up the fifth sheet for example, I have covered only twenty feet of wall 5 x 4 ft (OSB applied vertically) and there are four spaces allotted between the five sheets at 1/8" each - it seems I'm running out of nailing room on the stud. I'm supposing the sheet measures a true 48" and not 47 7/8". iS THAT MY ERROR? Or must I trim every second sheet by 1/4" to stay on schedule? If I'm doing a 40 ft wall there will be 10 sheets applied vertically and nine spaces between them. 9/8" and I'm certainly way off the stud! How is this typically handled?? Thanks

[julian abram]

I have built several houses applying 1/2"x4'x8' OSB vertical on walls, never left any space between sheets, just butt them up tight and nail them down. I never heard of any other builders in my area "spacing" OSB on new home construction. OSB will "swell" if you get it soaking wet, but never seen it expand across the width or length applied and covered on a wall. My 2 cents.

[Andrew Gold]

You're using T&G sheathing, right? There will end up being a small gap (1/8) sounds about right between the two faces of the ply, but the T&G eats that up.

I think you're over thinking this one

[Bradley Gray]

+1 on butting the sheets. Just try to get it covered with felt or house wrap as soon as possible.

[Peter Kelly]

Install the sheets horizontally butting each tightly together and cover with building wrap or tar paper.

[Larry Browning]

+1 for over thinking this one. Just butt em and don't worry about it. Millions of houses and building are done this way all over the country (and the world for that matter) without issue.

[phil harold]

I am going to say gap them
1/16th will work
while many times you may not have a problem other times it will bite ya in the butt
walls may not be as visible as a roof
roofs not spaced you can see each piece of sheathing year/s later

"you need to be smarter than the board"

[Jim Andrew]

I used to put the sheets on horizontally, and did not worry about the gap on the ends, but on the edges would start a nail so left a gap of the diameter of a nail between sheets. The real reason for the gap, is on roofs sometimes the edges will raise and you can see the offset on the roof. We did not worry about the ends of the sheet, just the edges. The edges are nailed solid, so hard for the sheet to move, but on edges between rafters, it can sometimes be visible.

[Andrew Kertesz]

We always built our walls laying down and nailed to the deck. Easier to keep them square and you don't have to try and rack them as much to plumb everything when doing your top plate. Sheeting was always vertical and never gapped.

[Dennis McCullen]

Hey - I think I found an answer that makes me happy, happy, happy! There should be something in the stamp on the OSB referring to "sized for spacing" and that sheet will measure 1/8" short on each dimension to allow for proper spacing! so 47-7/8 X 95-7/8" makes perfect sense. Drive a 6d nail into the stud near top and bottom edges, apply next sheet with the nails as spacers, the pull nails after securing the sheet. Thanks to all!

[Randy Gazda]

+1, that is what I did on my recent shop project. I watched the joint tighten up when the weather got wet (even though water never hit the OSB, the roof with overhang was already in place). Now with housewrap and cold some of the gaps reappeared.

Hey - I think I found an answer that makes me happy, happy, happy! There should be something in the stamp on the OSB referring to "sized for spacing" and that sheet will measure 1/8" short on each dimension to allow for proper spacing! so 47-7/8 X 95-7/8" makes perfect sense. Drive a 6d nail into the stud near top and bottom edges, apply next sheet with the nails as spacers, the pull nails after securing the sheet. Thanks to all!

[Gary Yoder]

I was a carpenter for years before a recent job change and have seen many ugly walls because of osb pushed tight together. Structurally it works fine, but osb WILL swell somewhat even under housewrap, producing cups and bulges. Osb is supposed to be made 1/8" undersized as you found. My experience is that sheathing tends to swell a little even before it gets put on the wall... Unless you have a long wall that will get sheatrocked inside, you can just stretch your stud spacing a little to accomodate whatever size your OSB is.

Just my 2 cents.

[Tom M King]

Take a half a saw blade while it's in the stack. When you use that much up, cut again.

[johnny means]

Leaving gaps in between the sheets of OSB is pointless. Any swelling would be in between the nails, in the middle of the sheet not into the gap.

[eugene thomas]

I costed the inside of my shop with osb. Stamped on sheet to leave 1/8" gap and of course didn't. So after 3 or so sheets one end of sheet to short to fall on truss.