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batt2

Precarious Construction

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An interesting method of construction! What issues do you see...

post-891-0-06546000-1302383186.jpg

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I do not see any cross bracing between the I beams, or connections to the building on the left. At least they appear to be set on the tops of the built out support columns of the building (possibly a garage). Second point is the connection to the brick house on the right. The I beams "connected" to the brick house do not appear to have adequate support. The brick wall was probably designed to only support the weight of the house above it, not the additional weight of the I beams and the addition pictured. There are two windows in the brick building of which one or more of the I beams may be in line with these windows, thus requiring additional construction to beef up the header on the top of the windows, and the side supports along the sides of these windows. I can't comment on the flooring support of the addition, (due to again the angle of the picture) but it does not appear to be adequate.

Good pic & topic Chief.

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I see many problems with this construction. One small detail is that it appears that the i-beams are making the roof of the white building sink. If you look closely it appears there are depressions under the i-beams.

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1. The steel beams appear to be just resting on top of the masonry (brick columns possibly added to the original white structure), and have no lateral support

2. The beams are unprotected steel (no fire protection) over what appears to be a common driveway between the two buildings.

3. Depending on how the steel beams are secured/ supported within the red brick building on the right, a fire in the white building, or even something (car) striking the building on those masonry columns may lead to a collapse of the second floor into the white building.

4. Without jacket, or traffic vest the firefighter in the back of the photo blends nicely with the black SUV :P

Edited by grumpyff

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From this angle, it SEEMS as though the almost "cantilevered" part of the building is original to the building. The brick facade and lintels seem to be the same age/type. I would think the building originally had posts holding it up, but the owner wanted use of the driveway/alleyway so rearranged it like this. One danger that this poses over what I think is the original design is a car fire underneath this area. There would be immediate extension to the building, and not much space to work.

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An interesting method of construction! What issues do you see...

A construction engineer that should lose his license! Love to know who approved this construction.

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On a second look, I noticed the white building has a pitched roof, which necessitated cutting the roof around the i beams. It probably was not protected properly in regards to water damage. I think the depressions that PFDRescue is noticing are these cutouts. Another viewpoint is that those beefier looking columns line up perfectly with the proper i beam locations. I wonder if the white building was built with this application in mind. Or those beefier looking columns could just be a pile of bricks against the cement block. Hard to tell without more photos from different angle.

Batt2- How did the rest of the property look?

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Brick building on right is Type IV const. maybe? Cant see the inside to determine exactly, but the wall itself is structural, you can tell by the way every fifth row of bricks is perpendicular, this means its a structural brick wall.

I personally would like to see the beams enclosed in some type of covering either masonry or spray on type. You cant truly see whats in the walls on either side to say whether its supported enough, or if the headers are built up or not...Whats behind those walls.

Atleast the addition only comes out half way and not all the way across. Are these two buildings owned by the same people or are they different properties?

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Was the area above the I-beams an addition to an already existing structure, or was the building built all together?

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I don't know the answers to most of your questions about the building. (Nothing else about the building is extraordinary.) I wonder as you do about the history of the I beams and the building next door. I love the points you all make and how many details were picked up. The Fire Prevention Division and Building Department have some work to do. In the mean time, we will have to deal with any fire that occurs under the beams in the driveway and the Exposure 2 building or any other incident which weakens that precarious load arrangement.

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Another question. Is the white building owned by the people who own the brick building or is it something abandoned and the owners found some shady contractor that didn't ask questions and illegally built onto the existing structure. Also I would rather see i beams as vertical supports over the modifications to the white building

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3. Depending on how the steel beams are secured/ supported within the red brick building on the right, a fire in the white building, or even something (car) striking the building on those masonry columns may lead to a collapse of the second floor into the white building.

This would be my #1 concern. It does look like sketchy construction. But I'm willing to give the benefit of the doubt to the structural engineer that some sound calculations were done. My main concern would be any fire load that could collapse the left building would collapse the while building.

As IC, any fire in the white building would immediately make me evacuate the right building

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My concern would be personnel being cut off and potentially trapped behind the structure in the event of a collapse. It is not visible if there was a secondary egress from the rear and how tight the rear area is for potential secondary collapse dangers.

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I tend to disagree with many of the observations... Structurally, I see nothing wrong with it. Additional photos would be helpful to support my disagreement. Esthetically, I have issues with it, but I'm sure there are reasons(which will probably will never know) for the way it was designed. Form follows function in this case! Tactically, there are concerns about rear access, unless there is another way to the rear other than through the brick or block buildings.

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I tend to disagree with many of the observations... Structurally, I see nothing wrong with it. Additional photos would be helpful to support my disagreement. Esthetically, I have issues with it, but I'm sure there are reasons(which will probably will never know) for the way it was designed. Form follows function in this case! Tactically, there are concerns about rear access, unless there is another way to the rear other than through the brick or block buildings.

I posted this photo because I believe this method of construction has implications to firefighters. Many methods of construction are adept at holding up the load under normal circumstances. I beams are very strong and are widely used in buildings. (And they are usually enclosed in a protection membrane or coated with a fire retardant.)

The method of construction in this picture has obviously worked for many years and probably will hold the load under normal circumstances. That said, I find concern that during a fire, the unprotected steel could cause collapse to the building it supports. A fire in the building to the left or an auto fire underneath could easily cause failure of the I beam. Firefighters responding at night in the building to the left might not immediately see that the building to the right is held up by steel which is being heated up.

Recently at a fire in Yonkers, a cockloft fire heated an I beam and pushed out a parapet wall, narrowly missing some firefighters. Steel elongates once heated. "Heated to 1000 deg. F, a steel member will expand 9 1/2 inches over 100 ft. of length...at temperatures above 1000 deg. F,...steel starts to soften and fail, depending upon load." (* p.272)

*All serious firefighters should read "Building Construction for the Fire Service" by Francis Brannigan. Chapter 7, titled "Steel Construction" is particularly relevant to this discussion. Be safe.

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I tend to disagree with many of the observations... Structurally, I see nothing wrong with it. Additional photos would be helpful to support my disagreement. Esthetically, I have issues with it, but I'm sure there are reasons(which will probably will never know) for the way it was designed. Form follows function in this case! Tactically, there are concerns about rear access, unless there is another way to the rear other than through the brick or block buildings.

Structurally, right now with no fire impinging on either building, you are correct. However, a car fire taking place underneath the overhang, or a fire in the single story white building, could have severely negative impacts on the structural stability of those beams. Steel, which I assuming they are, melts at 1500 C, however it weakens to 10% of its normal stability at 1000c. Car fires burn at about 1000C inside the passenger compartment (http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V37-4T7W3H3-2&_user=10&_coverDate=04%2F30%2F2009&_rdoc=1&_fmt=high&_orig=gateway&_origin=gateway&_sort=d&_docanchor=&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=0e160246c269adb86ffb54b7a8cae43e&searchtype=a). So a car fire occurring under the the beams would severely weaken the structural integrity of the building.

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Just a visual of what fire can do to steel beams, attached is a picture taken by a Poughkeepsie DC at a vacant warehouse fire.

Imagine if these beams were supporting an OMD.

post-20585-0-32029700-1303328097.jpg

Alpinerunner, CFFD117, batt2 and 1 other like this

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I should re-phrase my earlier statement to I disagrees with many of the structural statements. I do agree that the photo shows there is a potential to create interesting fire fighting tactical challenges. Fire and steel are not an ideal mix especially when they are in a confinded area. Protection of the steel members are determined by three items: type of construction, occupancy classification and general height and area limitations established by the N.Y.S. Uniform Building Code. In this scenario, I would not expect to see the steel protected. I find protected structures to be found often in large public assembly and health care facilities. The photo posted by Bullseye is a good photo of the roof purlins (steel) that have suffered under fire conditions. The steel in this case is light weight and similar to that seen in pre-engineered metal warehouse buildings spanning between the main steel bents that that span the distance of the building. Johnny OV mentioned the fire in the cars interior reached 1,000 Deg. C, (1,830 Deg. F) which is hot. A candle also burns at the same temperature. For the most part, this scenario to me is no differant than any departments that have buildings with a port-cochere where people are dropped off so they are out of the weather. A car could possibly catch fire underneith it... Structural damage is highly possible. I have seen plenty of port-cocheres with dry sprinkler systems just for that situation.

In our photo, I don't think the design intent was for a car to park under the structure as much as as it is a passageway. I would bet that a car fire under the overhang would be more likely to start a fire in the interior building above through convection if not extinguished in a reasonable amount of time. I would also bet by looking at the size of the steel members, that a car could burn and self extinguish before the steel deflected enough to fail. You have three open sides where the heat build-up would not raise enough for that steel to fail. It would be an interesting test! Good post Batt2!

Edited by 42121FD
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True, a candle also burns at 1,000 degrees, but a candle doesn't have the fire load that a car does. You could what if this to death, but its plausible to put a substantial fire load under this building that would expose it to high head condtions long enough for it to fail.

This is a bit different from your typical port-cochere as there is at least one story over this one. Traditionally a port-cochere is build adjacent to a structure and not under part of it.

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I posted this photo because I believe this method of construction has implications to firefighters. Many methods of construction are adept at holding up the load under normal circumstances. I beams are very strong and are widely used in buildings. (And they are usually enclosed in a protection membrane or coated with a fire retardant.)

The method of construction in this picture has obviously worked for many years and probably will hold the load under normal circumstances. That said, I find concern that during a fire, the unprotected steel could cause collapse to the building it supports. A fire in the building to the left or an auto fire underneath could easily cause failure of the I beam. Firefighters responding at night in the building to the left might not immediately see that the building to the right is held up by steel which is being heated up.

Recently at a fire in Yonkers, a cockloft fire heated an I beam and pushed out a parapet wall, narrowly missing some firefighters. Steel elongates once heated. "Heated to 1000 deg. F, a steel member will expand 9 1/2 inches over 100 ft. of length...at temperatures above 1000 deg. F,...steel starts to soften and fail, depending upon load." (* p.272)

*All serious firefighters should read "Building Construction for the Fire Service" by Francis Brannigan. Chapter 7, titled "Steel Construction" is particularly relevant to this discussion. Be safe.

Also chief, every firefighter should take the "Building Construction For The Fire Service" courses available. I took two of them and they are invaluable to have, lots of info about building components and the effects of fire impingment, collapse signs, load factors and such. Great course.

batt2 likes this

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'ny10570'- "Traditionally a port-cochere is build adjacent to a structure and not under part of it."

Show me a port-cochere that's not attached to a building then it's not a port-cochere!

porte-cochere

[n] - a carriage entrance passing through a building to an enclosed courtyard 2. [n] - canopy extending out from a building entrance to shelter those getting in and out of vehicles.

Sometimes... they don't have a building above, sometimes they do! Also... Many of the above opinions are plausible, I just thought the photo in this discussion need some defense.

Edited by 42121FD

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