Fire proof/resistant Bradley enclosure ideas

[drano]

I want to make a fire proof/resistant "home" for my OBS when I move to South Dakota this summer.  The house has a 2 stall detached garage, and I'd like to build its "home" inside the garage for all-year smoking which would include some version of a vent hood quite a few of you have built.  

I want a fire proof/resistant enclosure to keep an accidental fire contained on an over night smoke so I can reduce the possibility of burning down the garage.  

A couple ideas I have thought of:
- cement block enclosure with a light weight steel door
- firewall sheet rock, and use aluminum or steel angle iron for framing

What inputs do you have?  Are these reasonable?  Other ideas I haven't thought of?

I'd most likely modify my Maverick thermometer antenna for long range use, set the alarm as a high temp warning, and keep that on too.  

I'm sure quite a few people run their Bradley in the garage all nite w/out any problems.  But I don't want to be that small percent that gets a fire and then burn my garage down.   Currently I run it during the day only, and I'm always home to keep an eye on it.  

Thanks
drano

[classicrockgriller]

I don't know if you have added a second element to your Bradley,

but if you have you have you may want to consider putting the

added element on it's own Thermo fuse.

That way in the event of a temp rise you would totaly shut down

electricity to the elements.

I would think most fires in the Bradley are from Human errors.

I have started taking out the dirty V-tray before I got to bed on an

overnite smoke and replacing it with a clean one.

(I have two Bradley's, but you can buy another V-tray for it)

Also, I use an over size water pan and fill it before bedtime.

Those three things just about covers all the bad things that

can happen in your Bradley.

I do like your Idea of a "Fire proof/resistant enclosure.

[drano]

CRG,
Thanks for the quick response. 
I currently have one element, but want to add a second after I get settled in.  Sounds smart to have both elements protected w/ a thermo fuse.  And so does the extra v-tray and larger water pan. 

I currently do a rack of spare ribs or a 3 lb pork butt, and a couple times a year I do some sausage/snack sticks.  However, I want to do bigger hunks of meat and load it up more w/ sausage, so a safe over nite smoke would be nice.

All inputs/ideas welcome.

[BuyLowSellHigh]

That's great thinking.  It's not so simple once you get into the details.  If you build this as an enclosure to be effective you will need to be able to close it when left unattended, but it will need a spark arresting intake vent down low to be able to draw air for the exhaust.  Related, the exhaust for such a "room" would need to be constructed to kitchen ventilation standards  - if you ever did have a fire get going the vent itself becomes an issue (fanning a fire). 

A few thoughts.  First, I believe you can build a very reasonable fire resistant enclosure with wood framing covered inside (where the smoker will be) with 5/8" dry wall.  That's the standard generally followed for UBC construction on garage interiors attached to living spaces.  If you wanted to go overboard you could go thicker by adding layers, such as 3/8" over 5/8".  Add a fire-rated door or build one again with 5/8" drywall as the interior and you should have a decent enclosure.  Second, add a heat rise detector in the immediate area.  This functions like a smoke detector but uses temperature rise instead of smoke.   Finally, if you want to get really safe you could add an automatic discharge fire extinguisher like those used in the engine compartments of boats, something like this
http://www.fireboy-xintex.com/CG2-fire-extinguisher.htm

If you want to add the auto discharge extinguisher you'll want the HFC-227 version (the other not good for human exposure).  For a small volume they aren't that expensive and installation is simply hang it in the right place.  You can get an idea of price here

[drano]

I knew there were some building experts on this forum!
I guess the simple idea is full of limitations. 
Maybe I'll do a basic drywall box with enough venting to let it breath.  That would possibly contain a fire, but not create the issues of keeping it fully sealed.   And the heat rise detector would be a great safety feature to catch it early. 
thanks for the input!

drano

[KyNola]

Drano,
I'm not trying to minimize the risk of a fire in your Bradley but as near as I can remember I have never heard of anyone burning down their house/garage/well house/ from a fire in the Bradley.  I truly understand your concern.  I have seen pics of fires in a Bradley and the Bradley contained it very well.

I urge you to do whatever you feel you need to do to keep your family safe.

[BuyLowSellHigh]

Enclosed doesn't mean sealed - you still need air flow and exhaust to remove both heat and smoke (think about your kitchen).  I think a reasonable model to consider is the engine room on a smallish express cruiser.  For example, a 33 foot Sea Ray has an engine compartment that is about 10 feet square and 5 feet deep - 500 cu. ft.  In that "room" there are two big block GM engines.  It takes a lot of forced ventilation to keep things from getting out of control temperature wise (and fume wise too).  Still an auto discharge extinguisher is added in case something does get started.

In restaurants they use ventilated hoods (and add the auto discharge extinguisher too). Another way of thinking through it is to consider how to safely contain a burning fire within a building structure.  The fireplace comes to mind - just need a tall, big fireplace.  

[Quarlow]

I knew the fire expert would come in handy. Good info BLSH again.

[ArnieM]

I think KyNola has a good point.  Going beyond that, a heat sensor setup that would cut off power to the Bradley and sound an alarm would help.  Then, of course, there's a sprinkler system, Halon (if they still use it) or CO2.  Personally, I'd go for a system to put out a fire in case it ever happened rather than to try to enclose it.

You selling that Sea Ray Eric  ??? ???

[Sailor]

To build a "fire resistive" room and to be considered a "fire resistive" room then you will have to have 2 layers of 5/8 inch sheet rock on both sides of the stud wall.  This means you put up 1 layer of 5/8 inch on the inside then you tape and seal it then cover it again with another layer of 5/8 inch and tape and seal it.  Then on the outer wall you do the same thing.  This will then be considered a 2 hr rated fire wall.  Then of course you will have to invest in a 2hr fire rated door which can be a solid core wood door or a metal insulated door.  Then you have to consider ventilation to take fresh air to replace the air that the smoker is ejecting to the outside during the smoke.  Once you cut a ventilation hole or slot you no longer have the 2 hr rated room.  So that means that you will have to install a vent that has a Guillotine type fire damper on a fusible link that will melt and slam the shutters closed to seal the room.  Pretty expensive to do and wonder if it would be worth the piece of mind to do this.

A better option would be to construct a simple room with a 1 hr rating of one layer of 5/8 inch sheet rock on each side and a door.  You could spend lots of money putting in a UL 300 compliant fire suppression device however that is very expensive.  I would do a poor mans version of fire suppression.   I would install a 1 inch steel pipe through the wall at the top and fit a sprinkler head rated at 286 degrees and hook up a garden hose to the pipe.  Turn on the water when you go to bed and if you get a fire the sprinkler head will go off and extinguish the fire.  For a sprinkler head to properly activate and give the correct size of water droplets you need to have at least 15 psi of water pressure at the sprinkler head.

To reduce the risk of a fire make sure the smoke is finished before you go to bed and that the pucks have been ejected into the water.  The heating element is shielded by the V tray and fats should not drip on the element thus reducing the exposure of fire. 

The main thing to remember is that you have to have 3 things to have a fire and they all have to come together under certain conditions to have the fire.  You have to have heat, oxygen and fuel.  If you remove any of the elements the fire will go out.  Since the Bradley is pretty much sealed, any fire that starts inside will rapidly consume the oxygen and the fire "should" self extinguish before it breaks out of its containment. If you keep a pan of water to catch the grease dripping you are taking a lot of the fuel away.  The heating element is cycling on and off which is reducing the heat factor.

I now return you to your regularly scheduled smoke.  ;D

[Quarlow]

And you should hear what the guy who taught sailor had to say about this. :D :D :D

[ArnieM]

Sailor - Sounds like you been there, done that :D

[classicrockgriller]

I don't know if you have added a second element to your Bradley,

but if you have you have you may want to consider putting the

added element on it's own Thermo fuse.

That way in the event of a temp rise you would totaly shut down

electricity to the elements.

I would think most fires in the Bradley are from Human errors.

I have started taking out the dirty V-tray before I got to bed on an

overnite smoke and replacing it with a clean one.

(I have two Bradley's, but you can buy another V-tray for it)

Also, I use an over size water pan and fill it before bedtime.

Those three things just about covers all the bad things that

can happen in your Bradley.

I do like your Idea of a "Fire proof/resistant enclosure.

I totally agree with you!

First time I have been right in a while.

[Sailor]

LOL....Fire/Arson investigator for 13 years.  Then went to work for an insurance company in loss control which dealt with fire pumps, sprinkler systems, building construction and special hazards.  Tried to stop a fire before it started.  Now I own a loss control consulting firm and do work for major insurance companies doing the same thing.  Trying to engineer a building to not have a fire and if a fire starts to keep it from spreading. Insurance companies get a bit upset losing a 10 million dollar plant.  :o

[Quarlow]

I think BLSH was in the same type of racket. You 2 should get along well.