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    JTL
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    Default Falsework Fires - Demon in Concrete construction

    Just a few days ago I saw some torches being used in the vicinity of falsework for concrete construction. Knowing that it is a dangerous practice it gave me a pause and prompted me to ask my friends on this board the following question:

    What would be your actions if you pulled up to a 3 story structure with falsework in place until the concrete is strong enough? Would your department move within the falsework or take another approach? Lets say that the workers had all gone home for the day.

    On another note how often does this situation show up in your training, if at all?

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    I'm from S.C. and I've never even heard of this before. It must not happen in my neck of the woods. How do I know this you ask? (i thought i heard you ask) Because my Chiefs wouldn't not tell us about it. They know all.


    MO

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    JTL...

    Falsework fire, concrete still setting, no life hazard? Let it burn!
    The risk for collapse of the concrete is great and a fire in the falsework is not worth a firefighter's life.

    Firefighter MO...

    "Falsework" is the term for the wooden forms or molds used in pouring concrete in buildings under construction. If the builders are using concrete, you have a potential for a falsework fire! Oil is applied to the falsework to prevent the concrete from sticking. This oil impregnated wood will burn rapidly, much like the oil soaked floors old mill construction. Heaters used in construction during the winter can also cause these wood forms to dry out rapidly, thereby burning a lot easier.

    Here are some books that belong in every firefighter's library...the information contained within them can save your bacon!

    Vincent Dunn's Collapse of Burning Buildings and Safety and Survival on the Fireground.

    John Norman's The Fire Officer's Handbook of Tactics.

    Francis Brannigan's Building Construction for the Fire Service.
    Last edited by CaptainGonzo; 04-20-2002 at 07:11 PM.
    ‎"The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
    Lt. Ray McCormack, FDNY

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    JTL
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    Mongo

    Couldn't agree more. When I was the Fire Marshal I stopped my inspectors, etc. from walking under falsework. Many thought this a little extreme but it was my contention that the possible loss of life was not worth it.

    FFMO I have all three of the mentioned books. If you would like them, let me know.

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    You can often tell how long concrete has cured by the spacing of the bracing. If the spacing of supports is every four feet, it is a recent pour, 8 feet; 48 hours old, 12 feet; 72 hours.

    Assuming codes are met, of course. Bottom line is, the closer the supports are together, the greater the fire load and also the less time the concrete has had to cure.

    $.02

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    Default GONZO/MONGO THE SAME PERSON?

    Have you been holding out on us Cap?

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    Mikey...
    While Brother Mongo and I have a lot in common, we are not the one and the same...JTL must have been speed reading the forums again!
    ‎"The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
    Lt. Ray McCormack, FDNY

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    Default THANK GOODNESS

    I am not sure how I would react to a "Howdy pardner" in a "Bahston" accent..
    Last edited by MIKEYLIKESIT; 04-20-2002 at 08:17 PM.

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    Mikey...

    It would sound like this...

    hey theyah, howyadoin, pahtnah!
    ‎"The education of a firefighter and the continued education of a firefighter is what makes "real" firefighters. Continuous skill development is the core of progressive firefighting. We learn by doing and doing it again and again, both on the training ground and the fireground."
    Lt. Ray McCormack, FDNY

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    Default understands Massachusettese

    I have a good Boston friend, who when she describes where her place on the Cape is, she says HOW-ICH. I do work with a guy originally from the Springfield area and he sounds almost like he's from the mid-west..

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    I've been accused of being everybody but me...

    I can't decide who's in better company, Gonzo, you or me

    We just call 'falsework' concrete forms.
    It's only my opinion. I do not speak for any group or organization I belong to or associate with or people I know - especially my employer. If you like it, we can share it, you don't have to give me credit. If you don't, we are allowed to disagree too (but be ready to be challenged, you may be on to something I'm not). That's what makes America great!

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    Thanks for the new info guys. I also only called them concrete forms, but now I have a new word in my vocabulary.

    I'm with Gonzo, if the "falsework" is involved, and they've all gone home, they will have work for another six months. I see no point in risking my guys for some concrete and wooden forms and some tools.

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    Default

    Just like to say that I have learned two things on this post:

    1) I had no idea what "falseworks" were (I understood what "concrete forms were though - same thing)

    2) We don't get a lot of heavy construction in our district (mostly rural) and it would never have occured to me that the boards might be oil soaked, and therefore pose a serious hazard.

    Its nice to learn something at least once a day! Thanks for the info guys. Better to give the construction guys a few more weeks or months of work than risk someones life for no real good reason.
    If you don't do it RIGHT today, when will you have time to do it over? (Hall of Fame basketball player/coach John Wooden)

    "I may be slow, but my work is poor." Chief Dave Balding, MVFD

    "Its not Rocket Science. Just use a LITTLE imagination." (Me)

    Get it up. Get it on. Get it done!

    impossible solved cotidie. miracles postulo viginti - quattuor hora animadverto

    IACOJ member: Cheers, Play safe y'all.

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    Gentlemen -

    Concrete forms, and falsework are not the same thing.

    Concrete forms are metal structures (either steel or aluminum) that are faced with wood and give the concrete shape to form into. There are 'ties' that space the forms - and usually 'rebar'(steel reinforcing bars) that are placed between the the two forms. Metal forms used for pouring floor slabs are generally supported by metal supports/scaffolds - because they are metal - the fire load is greatly reduced.

    Often - companies will use wood to contruct forms. Same principles apply - but they must use tremendous amounts of wood in order to accomplish the task. And because they are not using a metal form - which can support the weight - then they must use falsework to support the weight of the wet concrete until it has 'cured' aka 'dried' enough to support it's own weight.

    Green concrete - or wet concrete needs much more support - and this is usually accomplished through the use of 4x4 timbers. Wet concrete can weigh as much as 150lbs per square foot when wet.

    as Eng Lt. from NY has stated:
    You can often tell how long concrete has cured by the spacing of the bracing. If the spacing of supports is every four feet, it is a recent pour, 8 feet; 48 hours old, 12 feet; 72 hours.

    Assuming codes are met, of course. Bottom line is, the closer the supports are together, the greater the fire load and also the less time the concrete has had to cure.


    I know all this because my father has been in the concrete forming business for some 30 years. I am not saying the hazards are any less with concrete -- just want to clear up the concrete forms vs. falsework issue.
    Marc

    "In Omnia Paratus"

    Member - IACOJ
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    -- The opinions presented here are my own; and are not those of any organization that I belong to, or work for.

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    Quote
    Wet concrete can weigh as much as 150lbs per square foot when wet.

    Concrete actually weighs 150 lbs a cubic foot not square foot, thus depending on the thickness of the pour will determined the loading in terms of PSI.

    Also remember most concrete will reach 70% of its design strength in 7 days, full strength in 28 days, the exception to the rule is High Early Strength which will do 70% in 3 days.

    Most large concrete companies today use metal forms for the simple fact they are easier to maintain and faster to setup but they will still use wood bracing to keep the forms in place during the pour.
    Metal forms are easy to clean and can be used many times over, where wood forms are junk after about 2 or 3 pours.


    On most storied buildings if the floors are to be concrete the bottom form is a metal decking designed for concrete floors but again will have wood underpinning to support the weight till the concrete cures

    I can speak on this only because I happen to be the Concrete Operation Manger for a local Concrete Supplier.

    As a firefighter my real concern is when was the pour made, many contractors will start taking the forms down in 7 or even less days.
    This would give most firefighter a false sense of security. If the forms are still in place you can bet its a fresh pour, lets say 3 days or less but if they are not, when was it poured 4, 7, or 28 days there is no way of telling by just looking at it. If you happen to get a fire near this concrete it's not cured enough, so what is the effect gonna be. Another point to ponder is if the concrete is pour within steal framework or has exposed rebar what will be the effect on the concrete from conduction of the heat in the steel.
    Pres41 (Pete)
    pres41@aol.com

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    JTL
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    JTL must have been speed reading the forums again!
    Thats true Monzo...I mean Gonzo. I figure your both great guys!


    Falsework is dangerous but ENgineLT gave some good thoughts. I do have to emphasize though, that codes are most often NOT met with repect to falsework. Not always, but often.

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