# Osb



## fjn (Aug 17, 2011)

I would check with my local building dept.,around here (N.W.In.) osb would never meet fire code. All drywall would also need to be at least fire taped. You never know,if at some point you decide to sell,you may be red tagged.


----------



## EricBrancard (Jun 8, 2012)

fjn said:


> I would check with my local building dept.,around here (N.W.In.) osb would never meet fire code. All drywall would also need to be at least fire taped. You never know,if at some point you decide to sell,you may be red tagged.


I know in my locale it's not the same if it's a detached garage. The firewall is to protect the living space.


----------



## jlsconstruction (Apr 26, 2011)

EricBrancard said:


> I know in my locale it's not the same if it's a detached garage. The firewall is to protect the living space.



Same here


----------



## hdavis (Feb 14, 2012)

jlsconstruction said:


> Same here


X3. Detached you don't have to do anything, although I'd have to double check if the walls were foamed whether they would have to be covered with something.


----------



## asgoodasdead (Aug 30, 2013)

I always space with 8 or 10d nails. H clips are only necessary for roofs 2ft on center. using them on a truss roof right now and they're a PITA


----------



## kiteman (Apr 18, 2012)

asgoodasdead said:


> I always space with 8 or 10d nails. H clips are only necessary for roofs 2ft on center. using them on a truss roof right now and they're a PITA



Just oversize them one size.


----------



## asgoodasdead (Aug 30, 2013)

kiteman said:


> Just oversize them one size.


this is what I've done in the past but didn't order them on this job.


----------



## superseal (Feb 4, 2009)

fjn said:


> I would check with my local building dept.,around here (N.W.In.) osb would never meet fire code. All drywall would also need to be at least fire taped. You never know,if at some point you decide to sell,you may be red tagged.


Around here we need to fire rate with 1 layer of 5/8 X type, any detached garages and sheds if they're wood construction and 3ft or closer to a property line. Only the property line sides are required.

At six ft. away, you may do as you please. 

If you're building with brick masonry veneer over studs or adding stucco cladding it negates that requirement if you're within that 3ft area.

I've actually built and installed sheds in the rear corner of small lots and and had to rock two interior sides of the structure to pass fire code inspection. Our local inspector is also our fire marshall so you're not getting away with it either unless it's unpermitted...even then, they usually nail your ass anyway as enforcement is pretty tight around here.


----------



## fjn (Aug 17, 2011)

Just my thoughts,osb would be way,way down on my radar screen for a finish material for any structure. Reasons being,fire spread is number one. Other reasons,no matter how many coats of paint,it is still quite rough and it will grab dust til the cows come home,not to mention the decrease in light reflective properties compared to a smooth drywall finish.


I could appreciate the better abrasion resistance of osb however,I would not let that sway me to its use for walls and ceilings. Just my ..02.


----------



## Spencer (Jul 6, 2005)

I have done it without spacing and it got wet. Looks like crap when it swells out and you can't fix it. I'd space it.


----------



## EricBrancard (Jun 8, 2012)

fjn said:


> Just my thoughts,osb would be way,way down on my radar screen for a finish material for any structure. Reasons being,fire spread is number one. Other reasons,no matter how many coats of paint,it is still quite rough and it will grab dust til the cows come home,not to mention the decrease in light reflective properties compared to a smooth drywall finish.
> 
> 
> I could appreciate the better abrasion resistance of osb however,I would not let that sway me to its use for walls and ceilings. Just my ..02.


I agree. Drywall with FRP over it makes a great garage covering. But, it certainly costs more than OSB.


----------



## WarnerConstInc. (Jan 30, 2008)

I put up 45 sheets of osb on the ceiling in my shop (1500 sqft detached garage) last fall.

They are butted tight, I heat the shop when I am out there working. I have had no issues. I did osb so I could easily fasten conduit, lights and dust collection piping to the ceiling where ever I wanted.


----------



## Golden view (Feb 16, 2012)

OSB will swell if it gets wet. If your garage interior gets wet, you have bigger problems.

Done this in garages before. Tight joints, no problems. Always liked being able to hang a nail anywhere.


----------



## flippinfool (Jan 6, 2009)

I think spacing is a must for new framing. The lumber will shrink a lot more than the OSB causing it to buckle. Old construction the lumber already dried out so the chances of OSB buckling is greatly reduced. I would but it up tight.


----------



## darthdude (Dec 30, 2012)

If your fire codes allow the osb to be used there then go ahead. But do space it, you said you're going to paint, so why not caulk in the gaps? A good elasteromeric caulk with flex with and expansion and you won't have the ugly gaps.


----------



## robert c1 (Mar 11, 2007)

I used OSB for the walls and ceiling in my shop. The acoustics were pretty rough so I skimmed it with mud before painting. Seemed to fix 90%. 
(I didn't space anything)


----------



## khash janpour (Feb 17, 2015)

think you will be just fine without spacing. Never had a problem with any of our similar jobs. Do what you feel is right however.. it all depends on code as to what you should and shouldn't use. spacing it would be the safest measure but it truly depends on what material you finally decide to use. taking advice is ultimately up to you. what sounds right for your situation. Nobody knows better than you, exactly what you're dealing with.


----------



## GettingBy (Aug 19, 2010)

"Like other wood-based panel products, OSB is hygroscopic and its dimensions change in response to a change in humidity. A 1% change in moisture content increases or decreases the length, width and thickness of the different grades of OSB by the amounts set out in the table below."

For length it's 0.03%, .03" out of 8' if I read this correctly. The thickness changes 20x this.

So, how much does the air humidity change the OSB humidity and how long does it take? Idk.


----------



## Robinsonfam1 (Feb 17, 2011)

biggest thing ive ever noticed with osb/spacing is when used as roof decking. if not spaced it can and usually will get "ridging". this is where you can see every sheet perimeter through the shingles. normally only noticed with 3 tabs due to their flat nature vs architectural. also most noticed when the sun is at just the right angle to the slope.

but yes it is a very real thing if not spaced properly on roof decks. ive never seen or had a problem on a wall. 

ive seen it happen when a low grade sub floor is used as well. since advantech though ive never used anything else since and most others in my area do the same.


----------



## kingcarpenter (Jan 30, 2015)

*osb*



pinwheel said:


> I'm planning to do the same in my garage at some point. I plan to space for exapnsion. I'd be scared of it bubbling out in the middle with no room for expansion.
> 
> If seeing the gaps bother you, just rip down the scraps of osb & put the strips over the gaps.


Now thats classy for sure. While your at it rip some 5" pieces to use as base. Maybe some crown too. To the op, climate and soil may play a little if your on the coast or in sand. Otherwise a small finish nail or butt it. You could always kerf it later but most likely not.


----------

