Good Example/Reminder About OSB Walls

[LocoCoco]

There are countless threads discussing the pros & cons of drywall vs. OSB sheathing. One downfall of OSB is that it's flammable.

Just always take extra care if you have wooden walls (like me):


Garage in Val Therese lost to fire Thursday night


Damage is estimated at $50,000-$80,000 in a garage fire in Val Therese Thursday night.

Greater Sudbury firefighters responding to a report of a garage fire at 4813 Frost Ave. about 9:20 p.m. found a garage engulfed in flames.

Firefighters from three stations used water and foam to fight the fire which caused heat damage to homes on either side.

An all-terrain vehicle, snowmobile, fence and items in the garage were all lost in the fire.

The fire was the result of the garage owner doing welding work and an aspenite wall catching fire, said Platoon Chief Dave Wickenden.


http://www.thesudburystar.com/ArticleDisplay.aspx?e=3044886



LC.

 

[ForceFed70]

So sorry to hear the bad news! My walls will be drywall.

 

[kb2tha]

Sorry to hear of your loss.

One half of my garage is drywall (divider wall down center) while the other side is OSB. My welder outlet is right below my panel box and next to an OH door. Any welding will be done outdoors. Unless of coarse it is on a vehicle that couldn't be moved.
Ken

 

[d110pickup]

I used OSB for the inside walls but I did take a couple of precautions. I left a 1/2" gap between the slab and the bottom edge of the OSB to prevent moisture from wicking up the OSB. Then I used a composite trim as baseboard and sealed it to the floor and OSB with caulk. My reasoning was to keep a spark from going under the OSB and smoldering.

As a side note I experimented with OSB and the baseboard material to find out how flammable it is. I couldn't get the OSB to burn after the flame was removed. The particular brand I used was definitely flame retardant. The trim material reacted the same way.

Mike

 

[LocoCoco]

Fortunately it's wasn't my garage, just a local article. It just caught my attention because people keep saying OSB can catch fire but I've never actually heard of a case. Then again, there's a chance a welding spark hit a pile of rags or something which then set the wall on fire.

I don't weld in my garage yet so my OSB should be fine, but when I eventually do get a welder I think I'll drywall over the OSB to keep the strength but add some fire protection.



LC.

 

[toolman1967]

Makes me rethink my decision to use OSB.I was going to use corrugated tin on the bottom of the walls 4 feet up on top of the OSB. I do a lot of metalworking, welding and cutting. in my garage now and was thinking I would be OK. Might have to rethink the design.

Thanks for the info!

 

[NUTTSGT]

Honestly, as a firefighter, I'd like to hear more of the story.
What was he welding ? some small stuff or a buch of heavy stuff.

How long after he quit welding did the fire occur ? did he wait around after he quit and go in the house or leave for work.

Unless the walls were oil soaked, I'd think it would take alot for it to catch on fire if the owner was right there working. A wet rag would have went a long way if a simple welding berry hit the OSB and started to smolder.

Listen, don't get me wrong, I know how easily a freak fire can start, how something can smolder and pop up. A few years ago, the local high scool was being remodeled. The construction crews left Thursday, after working on the roof. The had used a torch. Sunday afternoon it got windy, and something that had smoldered since Thursday took off. We got paged in, put it out and keep damage to a minimun.

 

[Dominico]

If the guy would have just used some "common sense" the fire wouldn't have happened. "This incident was caused by carelessness." You can't expect a bunch of sparks hitting a wood wall not to start some sort of fire. My home has thin coat plaster and that didn't stop an electrical short in a bathroom fan from catching fire. It caught a "wood" ceiling truss on fire. The home was built in 1986 using all licensed contractors. Luckily it was extinguished quickly with very little damage by the excellent fire department in our city (Monroe Michigan).

Don't believe for one minute that just because you have drywall walls a fire won't occur. By the way I grew up in the plaster and drywall trade (family business over 60 years) and have been on numerous fire repair jobs. Not one were OSB related. The point is, just do some research and educate yourself prior to doing anything. That is the main reason I am a member of this site. Some things still go wrong even after you have done your homework, however at least it won't be due to carelessness or lack of effort on your part.

 

[ptschram]

My shop is in a barn that was built about 1860. I'm scared spitless of fire and have multiple fire extinguishers and without doubt, the most valuable fire control/suppression device I have is a Hudson style tank sprayer filled with water and labeled as a fire extinguisher. If I catch a car afire (easier than you'd ever believe) while welding, it's fairly easy to spray it down and control it. Last night, it was used when the smoker caught fire with a brisket inside.

 

[nehog]

... Last night, it was used when the smoker caught fire with a brisket inside.

Do like we used to do, fill it with marinade sauce! Made some fantastic grilled chicken that way.

 

[Dominico]

That is exactly what I'm talking about ptsharm. You are prepared and educated in the event something should go wrong. No different that having a generator for power failures, a backup sump pump powered by city water to keep your finished basement from flooding as well as extra insurance specifically for this. By the way I have all of the above.

 

[Bull]

I think that if I ever get around to teaching myself how to weld, I will go over the OSB on my walls with some rock. Only 5/8 would "protect" me from the wall catching fire, is this correct?

I also reckon that it would be best to weld outside if possible, and that another precaution would be to use welding blankets and also screens around the work area.

 

[SpeedCoach]

I believe it is Jack who skinned his walls with some strips of aluminum flashing near his welding and grinding stations.....just another option for folks to consider.

 

[d110pickup]

I'll be welding on a project today and if I have some scrap OSB I'll either weld directly on it or I'll place it so the sparks land on it.
It's been my experience that it'll take more than a hot piece of slag to start a fire.
But just in case I have three fire extinguishers in the shop plus the ones in the trucks (if they are in the building) plus a water hose 30' away.
When I built the shop I included two smoke detectors at the peak and four heat detectors at the 13 foot mark. All locations were decided by discussion with my alarm company and the manufacturers reps.
Fire scares the **** out of me!
Mike

 

[bobbycoke]

I use 5/8 firecode drywall to close in my shop walls and cieling than around the walls above counters and workbenches I use 5/8 plywood for hanging tools signs **** etc..... my question is does the drywall make this wall any less or more dangerious???? I felt that buy not having both sides of the plywood expose to air that it would be harder to set on fire! Am I correct or just trying to convince myself otherwise, nothing will be fireproof and good work habits are a must to prevent any and all accidents...bobbycoke

 

[ptschram]

plus a water hose 30' away.

Fire scares the **** out of me!
Mike

At my old shop, I had to cable tie the water hose spigot open as my ex-brother-in-law was constantly closing the valve!

Doing such a thing makes sure that the water is always on and everybody knows it's supposed to stay that way.

Lots of good ideas here, it's pleasing to see that everyone takes this so seriously from a preventive standpoint.

 

[holdover]

reading some of these posts you would think that OBS bursts into flames like a Japanese tissue house, that is not so! OSB will burn as many other materials will. Take a piece of OSB and apply a torch to it, for short exposure it doesn't burn well, if at all, might discolor some, with long exposure anything burns! The key to all this is common sense, if you weld or grind next to anything that burns, you are going to have a fire at some point. Don't weld where sparks are going to ignite something, same with grinding, keep a spray bottle of water to cool/put out sparks when welding/grinding. Stay in the area awhile after you finish to make sure there isn't any latent sparks smoldering somewhere. Sheetrock is good, metal is better but OSB is not bad. Caution and plenty of available water and fire extinguishers is the best defense.(to limit damage as stated below) I base this on being a fireman for 49 years and investigating many a fire as to cause, and I am still active putting the wet stuff on the red stuff.

 

[ForceFed70]

[EDIT] This post is not directed at the post above or any particular post for that matter.

You can argue OSB safety untill you are blue in the face, but it doesn't change the fact that it is more flammable than drywall.

Everyone thinks they are perfect until it happens to them. You never know what is going to happen. **** happens, you can't always make sure you hang around for 30 mins after you finish welding/grinding. Distractions, phone calls, visitors, etc happen. Kids, friends, etc will likely use your garage at some time, etc. Sparks can smolder for hours before catching a flame.

Hoses, and other fire supression equipment is a great idea and should be in every garage. But they do not prevent fires, they only limit the damage.


This "It won't happen to me because I am smarter" attitude makes me shake my head. To me, it just proves the opposite.

Take the risk if you want, I'm fine with that. But don't try to tell us it's not a risk for you because you are smart enough to not let it happen.

 

[Bull]

This "It won't happen to me because I am smarter" attitude makes me shake my head. To me, it just proves the opposite.

Is anyone in this thread adopting that attitude?

 

[ForceFed70]

Is anyone in this thread adopting that attitude?

Good point. I think I am getting my threads mixed up. Sorry.

 

[ptschram]

Is anyone in this thread adopting that attitude?

No doubt. I was just saying how much I appreciated how seriously everyone was taking this topic.

I just got done pulling a fuel tank so I can weld on one of my trucks more safely. I will probably spend more time removing and replacing the fuel tank than fixing the rust holes in the loadspace!

 

[BBQ&Love]

I am a bit puzzled by the paranoia over OSB burning. As a former volunteer firefighter, I consider myself overly cautious about fires.

And yet, in my former career as a plumbing and heating contractor I often used scraps of OSB for flame shields with my MAPP gas fueled TurboTorch (much hotter than a propane torch) because it was so flame resistant. That doesn't jibe with the "OSB is a fire looking to happen" view some people hold.

What gives?

It matters to me because I am planning to sheet the inside of my 14x24 shop/garage with OSB in the next few months. It will be painted with Valspar Duramax paint so it will have a serious paint coating on it.

PS. I know Valspar Duramax is overkill for the inside of a garage. But I can get it for well under $20 a gallon for my personal use.)

 

[nate379]

So is aspenite Canadian for OSB? I've heard it called waferboard before.. guess aspenite makes some sense since it is made mainly with aspen.

 

[dirttracker18]

Not made from aspen around here and we had 2 mills that produced it.

I agree that people are fear mongering a little about OSB. If you have ever tried to burn it as others have you would realize that it would take a considerable amount of heat for an extended period of time to cause a fire.
On the flip side, isn't drywall coated in paper?? I realize the core does not burn but I would think the drywall with paper on the outside would catch much faster than OSB and spread much easier to other possible flamible objects/places/

Any thoughts from the FF's following this thread?

 

[ptschram]

On the flip side, isn't drywall coated in paper??

It's treated to be fire-resistant. Most drywall makes reference to being fire-resistant as well.

 

[djmartins]

And yet, in my former career as a plumbing and heating contractor I often used scraps of OSB for flame shields with my MAPP gas fueled TurboTorch (much hotter than a propane torch) because it was so flame resistant. That doesn't jibe with the "OSB is a fire looking to happen" view some people hold.

What gives?

Just your basic paranoia.
I used 1/2" sheathing instead of OSB to make painting it easier and it looks a LOT better!
Fill the holes and seams with mud and am in the process of painting it.
Not worried about fire, just be careful, as usual......

 

[Rickochet]

Most drywall papers will burn allowing the gypsum to crumble and fall in a heap. If one exhibits extreme OSB paranoia, better build the garage out of block!

 

[Vicegrip]

Most drywall papers will burn allowing the gypsum to crumble and fall in a heap. If one exhibits extreme OSB paranoia, better build the garage out of block!

Drywall is made from hydrated gypsum and for a reason more than it is an inexpensive material. Funny thing about hydrated gypsum when it is cold it looks and feels dry and even when left in the warm sun it looks and feels dry. Now heat it to the point that the paper and wood studs start to burn and a chemical reaction takes place. This reaction produces water from the hydrated gypsum and a good amount of it. It is not just that drywall does not support fire it helps suppress it. Once OSB reaches its tinder point it catches fire and adds thermal energy to the room. This added thermal energy helps the fire not helps suppress it. Drywall helps keep a fire from moving from room to room and helps protect the framing that supports the walls. A small rag fire just might stays a small rag fire rather than igniting the OSB and being fed by the walls themselves and consume the structure. Hydrated gypsum suppresses fire, OSB is a fuel. Not irrational fear or internet pseudo factoids, it is basic chemistry and well known science.

 

[Torque1st]

rkeep a spray bottle of water to cool/put out sparks when welding/grinding.

Whenever I weld, grind, or use a torch I always have a spray bottle next to me for putting out fires before they get going etc. The spray bottle works well for cooling sparks and burns as well as putting out fires on your clothing.

Fires don't seem to start easily on a flat exposed surface. They seem to start easier when there are flammable surfaces facing each other so they radiantly heat each other and get the chimney effect going. Sealing up a wall to avoid cracks and crevices where sparks can catch is good. Sheet metal helps in this regard, even a good coat of paint helps.

Even 3/8" drywall over OSB should provide some flame resistance. The 5/8" fire rock has additional thickness to delay temperature rise on the other side and increase the fire rating.

Vicegrip, is correct about the hydrated gypsum.

BTW, I have always kept some asbestos shingles around to shield combustible materials when welding etc. A more modern environmentally safer material is Hardie backer board. It is a bit thicker but it saves my shingles for the tight spots.

 

[PCO6]

So is aspenite Canadian for OSB? I've heard it called waferboard before.. guess aspenite makes some sense since it is made mainly with aspen.

Oriented Strand Board (OSB) was originally made from Aspen trees. They were fast growing and were harvested for that purpose. I understand Aspenite was a marketing name. OSB is now also made from Southern Yellow Pine and some hardwoods so "Aspenite" isn't quite accurate.

 

[ptschram]

BTW, I have always kept some asbestos shingles around to shield combustible materials when welding etc. A more modern environmentally safer material is Hardie backer board. It is a bit thicker but it saves my shingles for the tight spots.

Transite is completely safe as long as it's not been damaged and become frangible (?)-it's been awhile since my last ACM class.

I have a piece of thin stainless steel I use as a shield for those situations.

 

[Rickochet]

I certainly agree that standard drywall is more fire resistant than standard OSB. However, fire resistant OSB is now available. It is very prevalent in locales prone to wild fires. Note fire resistant term--- there are very few materials that are completely fire PROOF. Even stone & concrete can melt or disintegrate with enough temperature.

To help combat a fire where welding is conducted, make sure that you have a highly fire resistant material serving as a barrier at all times!

 

[NUTTSGT]

The biggest problem with the OSB/drywall argument, is fire. While it is generally predictable, it has a mind of its own.

. . . . little long here.....

Say you put up OSB and covered it with drywall, should be safe right? Last summer we had a house fire. Upon arrival, there was smoke in the house. We checked the entire house, light smoke but nothing inside. Smoke started building and coming out of the eaves and around a window. I went up on the front porch roof, started pulling siding. At the same time, another FF started opening the interior wall, close to where I was working. He found 3/4" pine paneling covered by drywall. (remember my first line, drywall over OSB) He continued to open the wall while I pulled the exterior aluminum siding. I found the fire first and put it out.
We checked the enitre wall and nothing burned on the inside, no electrical in the area to cause a fire. What we did find was this and noted it as the cause, electrical in nature. Somebody had done some work in the breaker box and the meter base had a bad ground, there was arc marks found when it was replaced. The electrical service was searching for a ground and it found it. Where? The bad ground ran from the meter base or breaker box(I don't remember at this exact moment) to the aluminum siding, from the siding to the aluminum spouting right down the down spout and into the ground. In the mean time, it arced on a nail and heated it up. The nail got hot enough to start a fire in the exterior wood sheating of the house.

So what am I saying? Take all the precaution that you want, be as careful as you can, but it's life and when it's your time it's your time, and accidents happen.

 

[ptschram]

The biggest problem with the OSB/drywall argument, is fire. While it is generally predictable, it has a mind of its own.

. . . . little long here.....

Say you put up OSB and covered it with drywall, should be safe right? Last summer we had a house fire. Upon arrival, there was smoke in the house. We checked the entire house, light smoke but nothing inside. Smoke started building and coming out of the eaves and around a window. I went up on the front porch roof, started pulling siding. At the same time, another FF started opening the interior wall, close to where I was working. He found 3/4" pine paneling covered by drywall. (remember my first line, drywall over OSB) He continued to open the wall while I pulled the exterior aluminum siding. I found the fire first and put it out.
We checked the enitre wall and nothing burned on the inside, no electrical in the area to cause a fire. What we did find was this and noted it as the cause, electrical in nature. Somebody had done some work in the breaker box and the meter base had a bad ground, there was arc marks found when it was replaced. The electrical service was searching for a ground and it found it. Where? The bad ground ran from the meter base or breaker box(I don't remember at this exact moment) to the aluminum siding, from the siding to the aluminum spouting right down the down spout and into the ground. In the mean time, it arced on a nail and heated it up. The nail got hot enough to start a fire in the exterior wood sheating of the house.

So what am I saying? Take all the precaution that you want, be as careful as you can, but it's life and when it's your time it's your time, and accidents happen.

Talk about something one really couldn't plan for!

I've had three instances of incipient fires due to poor wiring by a former owner of my home-and he was a licensed electrician. The last time,I discovered the main ground for the shop was not securely connected and green/corroded, etc. I have the cover off of my breaker box so that if something happens again, I can see/find it. Looks bad, but it's about six feet off the ground and I prefer having it be visible than having the cover on it. Yeah, I know, not particularly safe but better to know if the box is arcing and sparking than not, I guess. Yes,I've gone through and tightened everything.

 

[Torque1st]

NUTTSGT, nice example of Murphy's Law.

It is hard to ignite solid materials without a source of heat. Finely divided materials on the other hand are easier. Even normally non-flammable materials like metal can be ignited when finely divided. I doubt OSB can be ignited with just grinding sparks. Sawdust and splinters can be ignited. That is one reason to caulk seams and put on a nice coat of paint. There are even fire-resistant paints to use. Hopefully the owners of the patents on TimberSil wood will get their heads out of their a** someday and make TimberSil wood products widely available. Then we can have some good water, termite, rot, and fire-resistant wood.

 

[Dominico]

NUTTSGT, very good example. Appreciate your thought process as well as your personal experience as noted on your last post. Point well taken.