Another roof collapse due to snow loads, this time in California...

[JohnRBaker]

Drone video shows market roof collapsed by snow in California

https://news.yahoo.com/drone-video-shows-market-roof-105701361.html

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[FacEngrPE]

https://weatherstreet.com/city_snow_depth/92325-Crestline-CA-snow-depth.htm

That's a huge snow depth.

 

[dold]

~2 ft. ish?

 

[hawkaz]

Per San Bernardino county info- Structures in Crestline should have been designed for a 75 psf roof snow load

 

[spsalso]

How very interesting. I should think someone in the Building Department would be pulling the plans when they get to work on Monday. Or perhaps they couldn't bear to wait, and are there right now!


spsalso

 

[weldstan]

These were unpresidented snows in the San Bernadino Mountains. One must also need to know the requirements during market construction.

 

[JLNJ]

I find it interesting that the whole roof seemed to collapse at once. I would have expected a single bay or two or three.

75 psf is 3 or 4 foot of snow. Collapse at 6 or 7 feet? Dold's 2 feet looks a little shy or actual, but not 6 or 7 feet.

Maybe it was a drop-in-beam system which had a quickly cascading type of failure.

 

[IRstuff]

The building is at least 40 years old, and lots of things might have shifted in that time, since we've had a multitude of earthquakes during that time. I find it interesting that almost all (~80%) of the roof wound up disconnected from the walls. It's also possible that the roof, being flat, has been re-roofed a number of times in the 40 years, adding to the static loading; each re-roofing potentially adds 5 lb/sf.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[dik]

That's why I use plastic design...

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[TugboatEng]

Another California roof collapse. No snow though.

https://www.ktvu.com/news/coffee-distribution-warehouse-roof-collapses-in-oakland-1-killed

New building. Tilt-up construction which is very common lately.

 

[JohnRBaker]

Considering the extent of the recent rains, this could well be the result of a clogged roof drain(s). If this was new construction, and if this was the first significant rain since it was completed, the drains may have been faulty from the get-go.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[hokie66]

Probably right, JRB. Who is responsible for designing the roof drainage system for a building like that in California?

 

[RedSnake]

dold, the thickness has little to do with the actual weight in this case.
It seems to me that you would need this kind of website that we have. ;-)

Current snow/(water) weight in relations with required building norm for snow weight..

“Logic will get you from A to Z; imagination will get you everywhere.“
Albert Einstein

 

[spsalso]

There was also mention of a possible new roof within the last two years.

Here is an earlier view of the roof:

[URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1678484288/tips/Peet_s_roof_before_fnkna9.tiff[/url]


spsalso

 

[TugboatEng]

It happened in a corner. One would think that the roof would be strongest in a corner.

 

[JohnRBaker]

Why...

It could have been something as simple as a beam bending and the supported end being pulled away from the supporting wall.

John R. Baker, P.E. (ret)
Irvine, CA
Siemens PLM:

The secret of life is not finding someone to live with
It's finding someone you can't live without

 

[JLNJ]

If seen some pretty flimsy roof-deck-to-precast-wall connections. I'm a little surprised that there are not more of these failures.

 

[LittleInch]

Someone practicing with Chatcbt??

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[JAE]

I think so.

 

[IRstuff]

Poster's location is flagged as PK, so maybe just AI-aided translation; only time will tell.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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