OSB heat/flame test

[nonhog]

Just backyard attempt to see how easy or hard it is to ignite OSB.
Our results are: its pretty dang hard.

Held a match direct to the OSB. Would not light.

Held a rod heated with a MAP gas torch. No light

Sprayed brake clean on the OSB. Caught but went out in about 30 seconds.

MAP gas torch direct to OSB for 20 seconds. Caught then went out in about 40 seconds.
Smoldered for 10 minutes +/- Cold to the touch after 15 minutes.

Scientific? No. Proof of fire resistance? No. Good way to hang out with my 14 yo. Yes!

I'm still using sheetrock in my welding/grinding area.

 

[GOLF for LIFE]

Thanks NON, you answered one of the questions that I have had for sometime regarding OSB. How does it compare to plywood of the same thickness?

 

[dirttracker18]

Just backyard attempt to see how easy or hard it is to ignite OSB.
Our results are: its pretty dang hard.

I'm still using sheetrock in my welding/grinding area.

Try that with a piece of sheetrock and see how fast that paper on it goes up. The inside will not burn but it will climb a wall very fast and spread to anything flamable.

Seen it happen and that is why I use nothing but OSB in my shop. In my welding are I put up sheet metal to repel the sparks.

 

[nonhog]

Thanks NON, you answered one of the questions that I have had for sometime regarding OSB. How does it compare to plywood of the same thickness?

I bet my boy would love to find out

I did this because much of my shop will be/is covered with OSB.
I'm more comfortable with it now. I've read so many times on how dangerous it is.
Its still wood so YES it will burn, and be much worse in the case of a real fire in the shop,compared to sheetrock or metal. However (I FEEL*) the chances of it starting because the OSB is very low. Thats why I did the test.

*Disclaimer-figure it out yourselves, don't take my word for it.

 

[nonhog]

Try that with a piece of sheetrock and see how fast that paper on it goes up. The inside will not burn but it will climb a wall very fast and spread to anything flamable.

Seen it happen and that is why I use nothing but OSB in my shop. In my welding are I put up sheet metal to repel the sparks.

Sheetrock test? Will add that to our list of burns.
Also painted sheetrock, really does anybody leave sheetrock unpainted?
I don't. Be interesting to see the differance. If one?

I too plan to add metal in places, behind the welding/grinding area.

 

[NOVA87Wrangler]

Sheetrock test? Will add that to our list of burns.
Also painted sheetrock, really does anybody leave sheetrock unpainted?
I don't. Be interesting to see the differance. If one?

I too plan to add metal in places, behind the welding/grinding area.

Yeah, I would be interested to see if painting the OSB would make a difference as well.

 

[Cryptic1911]

Interesting, people usually say to put up drywall instead of OSB because of fire.. me included. I would have assumed it would go up like a pile of hay, seeing that it's all glue and wood chips

 

[jimindm]

Has anyone ever tried hardiplank siding. I think it comes in sheet form now. When we sided our house we used it. My father in law took some scraps home. I found some in his burn barrel a couple of years later, that still looked pretty good. I think it is advertised as fireproof.

 

[JimVonBaden]

Interesting, people usually say to put up drywall instead of OSB because of fire.. me included. I would have assumed it would go up like a pile of hay, seeing that it's all glue and wood chips

The paper may flash off, but 5/8 sheetrock is flame rated for an hour. I promise if you try to burn ply or OSB for an hour, it will easily burn right through in far less time.

Claiming OSB is more fire proof is just foolish.

Jim

 

[clarkebd]

Sheetrock is the better bet by far.

Then hang up fiberglass blankets by your area if you are really worried.

 

[Falcon67]

>Has anyone ever tried hardiplank siding.

Hardi is cement board - kinda hard to catch it on fire.

 

[nonhog]

Planned on testing more tonight but my helper went to the Avengers movie.
More to come!

 

[thdewey]

Thanks for starting this post.
Will it end the debate? NO
But I've got OSB in my shop and I plan on putting light corregated roofing on the ceiling, unpainted. I feel that this is a good combination for what I use my shop for.
If I start welding, it'll be outside the shop! And the outside of the shop is hardie board lap siding.

 

[clarkebd]

So to resurrect an older thread....

Did you ever do the Sheetrock vs painted-Sheetrock vs painted OSB flame test as you mentioned?

 

[willymakeit]

If your worried about osb, paint it with a intumsecent paint. Watch your product as some of it can be flamable when first applied.

 

[nonhog]

So to resurrect an older thread....

Did you ever do the Sheetrock vs painted-Sheetrock vs painted OSB flame test as you mentioned?

No. It was a project with my son who spends summers with his mom.
Now that he's back for the school year and currently not in any sports, maybe I'll set that up. Have all the goods in the shop.

 

[ForceFed70]

I suspect you would have had the same results if you'd have tried straight plywood.

Common sense tells us that wood burns fairly easily. It's just that people think it's easier to light than it really is.

 

[Tim The Tool Man]

Where I live and with the work I do it is advantageous for me to burn my construction debris. I can tell you that OSB is by far the most flammable of all the sheet goods. 1/4 luan is next, then on up as you go thicker with plywood. Drywall actually does burn but just the paper coating. Painted products burn a bit slower.

The key to igniting any of these is a bit of kindling. Once flame is allowed to consistently burn the wood for 2 or 3 minutes, up it goes.

Gas, rags, or trash, once ignited in a shop lined with OSB will take but a few minutes to engulf the building. Ask any fireman who has had to to put a fire out on a house with Waferboard I-beams...

 

[nonhog]

Not anywhere near proof of anything but we lit sheetrock today.
was a bit windy and the paper burned well. The paper that was free of any
gypsum. It went right up but went out quickly. I tried to light it from the middle to see if the flames would spread and it just would not light.

Also gave OSB another go. My firefighter buddy said if I had the OSB verticle it would light and quickly. Not saying he is wrong but it did not go that way today for me and the boy.

I invite others to try this. Add to the thread. I'm running out of Mapp gas.

 

[Architorture]

regardless of the burn characteristics of OSB, i don't think i would ever want to cover every surface of a relatively small, enclosed space receiving minimal air changes with a product that in all likelihood will be considered as dangerous as asbestos in the future.

 

[darcyh]

regardless of the burn characteristics of OSB, i don't think i would ever want to cover every surface of a relatively small, enclosed space receiving minimal air changes with a product that in all likelihood will be considered as dangerous as asbestos in the future.

Hello:

Why do you feel it will be considered as dangerous as asbestos?

 

[rickyboy]

Real interesting thread.....I'm think'in of tearing off the dry wall in order to insulate the garage and then replace it with OSB. Now I'm a little undecided on if I should or not. Keep talking guys.

 

[DEnd]

Hello:

Why do you feel it will be considered as dangerous as asbestos?

My guess is off-gassing of formaldehyde and other VOCs that are used in or created by the glues. While plywood off-gasses too, it doesn't do it to the extent that OSB does. It's mainly a problem when it's new, as over time off-gassing diminishes.

 

[DEnd]

Real interesting thread.....I'm think'in of tearing off the dry wall in order to insulate the garage and then replace it with OSB. Now I'm a little undecided on if I should or not. Keep talking guys.

There are other options besides traditional drywall and OSB/Plywood. One of those is non-paper faced gypsum board. Another is cement based "backer" boards, such as HardieBacker. These of course cost more, and don't necessarily provide as nice of a finish.

 

[Tim The Tool Man]

Wood and Masonite garage doors burn up real quick too!

My boy and I burned one of each yesterday and timed it for posterity...

This is our OBS results: The OSB was laid horizontally over a pre-lit fire consisting of cardboard and old wet firewood. The images are in one minute succession and it took about 5 minutes to completely consume the 2 X 8 sheet of OSB.

Verdict? Not a good product for a ceiling if you have combustibles around.

 

[Tim The Tool Man]

Here are the garage door results.

The door went even quicker than the OSB! I tried to prop it Vertical like a real door would be with maybe a gas can or old rags piled nearby. The door was completely consumed in about 3 minutes. The attached pictures were shot over a 3 minute span...

Verdict? Buy a steel door!

Also worth noting is a chunk of drywall still hanging around from when I burned some junk about 2 weeks earlier. Drywall will burn but it needs a concentrated source of flames to get the paper ignited. The gypsum won't burn of course but I like tilling the remains (ash and gypsum) into my clay soil when I am planting new lawn around my house.

And this is the fire 14 minutes after I first lit it.

 

[Falcon67]

My guess is off-gassing of formaldehyde and other VOCs that are used in or created by the glues. While plywood off-gasses too, it doesn't do it to the extent that OSB does. It's mainly a problem when it's new, as over time off-gassing diminishes.

If the OSB around here had any of that, my wife could not have helped me work with it or stayed in the shop any length of time. She is very sensitive to things like that and we never noticed any sort of problem. She can't stay in the lumber part of a big box store for more than 5 minutes without risking a headache/sinus or worse. So I would call "not" on glue issues with OSB, here at least. Our shop has 2200 sq/ft of OSB on the walls and ceiling.

As for fire - I spent 12 years in the old shop doing all the usual hazardous operations. The walls and ceiling were 80% kraft paper because I never got around to putting anything over it.

 

[Architorture]

My guess is off-gassing of formaldehyde and other VOCs that are used in or created by the glues. While plywood off-gasses too, it doesn't do it to the extent that OSB does. It's mainly a problem when it's new, as over time off-gassing diminishes.

^^^^^this which is worse than asbestos, which doesn't do anything harmful if left undisturbed...

but also similar to asbestos, when OSB is worked with and made airborne you are putting all of those glues and chemicals into the air and ultimately into your lungs.

i'm not scared of asbestos because it can be handled and worked with safely, yet it is more dangerous than your typical building material so i wouldn't go out of my way to use it despite its many advantages. i treat OSB in a similar fashion and it has hardly as many advantages as asbestos.

 

[TractorJeff]

This is an interesting thread that was picked up by a couple of guys on another forum!
Nice to see it resurrected for another "Go-Round"!

 

[rustyjames]

Where I live and with the work I do it is advantageous for me to burn my construction debris. I can tell you that OSB is by far the most flammable of all the sheet goods.

Agreed, OSB might not light off readily but once it gets going it really takes off.