A while back I wrote a nice article on balloon frame construction, which today drew the attention of a fire official of some kind , and he e-mailed me a question regarding his interest in fire blocking to prevent the natural chimney effect that occurs during a fire in one of these structures.
My question for anybody, is how would I be able to go about inspecting a ballooon frame for fire stops , which are required by most building codesThis is a serious safety issue and will appreciate all ideas.
Drill holes and stick in a boroscope?
Thats all I can think of.
Under the right conditions, I can see the fireblocking with my BCAM. . .
You might be able to pick up the block line with a studfinder. Bear in mind that the maximum vertical distance between firestop is 10’ and that may give you an idea of at what height to start looking.
I was not aware of the seperation requirement.
B cam will wait for the $1,000 model.
Boroscope wouldn’t seem to help if the walls were insulated.
If they aren’t insulated you could look up with a mirror from the basement perimeter in many cases but would possibly see the first one only.
http://www.brynmawr.edu/Acads/Cities/imgb/nextone/med/1002.jpg
In our codes, the firebreak isn’t needed if the walls are fully insulated since the fire won’t race up a filled cavity like a hollow one.
When balloon frame buildings were built from the mid 1800’s into the early 1900’s, fire blocking wasn’t generally being used or even considered.* It would be safe to say that there is no fireblocking. Tell the buyers to have insulation blown in the walls after re-wiring (or if the current wiring is safe) and kill 2 birds with one stone- save energy and make the dwelling more safe against fire spreading through exterior walls.
*There may be certain local building practices that installed a lot of diagonal bracing/blocking in each wall stud cavity, (some times called “herring bone” style). Don’t know if this was for strength or fire blocking.
If the construction pre-dates the requirement for fireblocking, the township will not require it.
Tough to inspect. Sometimes, if the home is renovated, the fireblocking is installed, though most times, it is not.
I have a standard write-up in my framing section with regard to balloon sonstruction, fireblocking, and the lack thereof. I encourage them to perform an invasive inspection and to install fireblocking if none currently exists.
How many do you believe actually follow-up?
There is a tool used by engine builders, and auto repair shops. It is a smoke machine to monitor the flow of air. I don’t know what effect the insulation will have on the flow of smoke.
Hi. Bob, and I am with you that I do not have fancy tools of the trade.
Maybe sometimes we could look at things and say, ahh if I went in the cellar of the balloon framing, I could see up the wall.
No cellar eh, well go up the attic and drop your good quarter in the cavity, I know, your precious quarter.
Well, try this one, take the wall plate off the receptacle and shove an electrians snake up or down the wall until you hit or do not hit blocking which should be at floor level or at the second floor level.
If you need a wire, use a #9 form wire, that works too. ha. ha.
Can I submit for Innovation ? 
Marcel 
Good answers so far.
Yes I would imagine fire blocking was not used untill around the same time they stopped building alot of them.
Sometime around or before world war two.
Marcel I was excited to see what answer you would have, but you instead tell me to go electrocute myself.Thanks Buddy.
Well, thank god your still alive Bob. ha. ha.
I forgot to tell you you need to shut the power off.
Marcel 
Marcel:
Found a bit still hanging around the web on Charlie Wing, Founder of Conerstone School of Building that was in Brunswick in the 1980’s:
*Charlie Wing, Smart HomeOwner’s technical editor, is the author of 16 home improvement books. Wing graduated from Bowdoin College, where he later taught physics, and holds a doctorate from MIT in physical oceanography. He wrote and hosted a 13-part PBS series called “Housewarming with Charlie Wing” and co-founded the Shelter Institute in Bath, Maine, the nation’s first school to teach potential homeowners how to build their own shelters. He lives on a lake in New Limerick, Maine
Charlie Wing
Charlie Wing received his Ph.D. in oceanography from MIT, where he later worked as a research scientist. Since then his career has been explaining how things work–teaching physics at Bowdoin College, founding America’s first two do-it-yourself house-building schools (the Shelter Institute and Cornerstone), hosting a PBS series on energy conservation, and writing a dozen top-selling books on home building, home maintenance, and remodeling. Wing lived aboard a cruising sailboat for six years, during which time he wrote the first edition of this book on a solar-powered Macintosh computer. He is the author of four other IM books.
That is interesting, Brian
Thanks, I am working on a Bowdoin Project right now.
Marcel