San Francisco Balcony

[Silas Gull]

Terrible tragedy in San Francisco. The Daily Mail's website carries quite detailed pictures of the failed balcony, which looks to be based on projecting timber joists.
Does anyone with more knowledge than me have an opinion on what might have caused this awful event?

 

[marcros]

the radio on the way home suggested that there were about 13 people on it, and that it looked suitable for 3 or 4 at most based on size. I havent seen pictures, or heard anything else.

 

[n0legs]

Nasty accident, very nasty.
I guess they'll say it was overloaded.

 

[woodpig]

I've just seen pictures on TV but I still couldn't make out the construction method. The Americans do persist in using timber in building construction where most other countries would use steel or concrete so this may be a factor.

I walked round this when it was still a building site and you might be surprised to learn that apart from the steel beams in the ground floor the rest of it is built of timber. This is In Canada but I know the Americans do the same.

http://www.grandgeorgian.ca/view/photos.aspx

 

[woodpig]

Pictures on the news today looked like they used 10"or 12" x 2" timbers.

 

[n0legs]

Pictures on the news today looked like they used 10"or 12" x 2" timbers.

Yea I spotted that.
Do they look like they've suffered rot to you?

 

[woodpig]

Hard to say it was only a quick look, I'll pause it next time to see if there's anything obvious. Those on site should have a good idea by now.

Edit: just seen this, does indeed look like rot.

 

[monkeybiter]

I was confused by the pictures, at first I thought it was a fully enclosing railing of ironwork and that a small roof had collapsed onto them, but after finding it on google streetview you can see that the upper railing has toppled 180 degrees and is now resting upside down on the lower balcony. The floor has fallen either inside and/or outside.

Sorry if that was obvious to everyone else.

EDIT:-
Initially written prior to woodpig's post, which is more explanatory than the pictures I had seen.

 

[Mcluma]

I was confused by the pictures, at first I thought it was a fully enclosing railing of ironwork and that a small roof had collapsed onto them, but after finding it on google streetview you can see that the upper railing has toppled 180 degrees and is now resting upside down on the lower balcony. The floor has fallen either inside and/or outside.

.

At first i was thinking the same - that a balcony from above had fallen on them

The pictures above suggest wood rot - I guess they will now close all the other balcony's

 

[No skills]

The beams look like laminated ones.

Hmm, not so sure. Bits of them kinda look like soggy bits of osb, others dont.

 

[woodpig]

Perhaps it wasn't just a static load?

http://www.nytimes.com/2015/06/17/us/ba ... .html?_r=0

 

[RobinBHM]

The 7 or so cantilevered joists in a new condition would take a pretty high load, but a flat surface externally would be difficult to keep weather tight so its not surprising these have rotted. What does seem surprising is that a balcony so high up doesnt have to made in a more durable material like steel or reinforced concrete.

I understand the balcony needed to be built for a 60lb per sq ft load, which may have been a bit less than the load this balcony was subjected to.

A terrible accident.

 

[Silas Gull]

It is now being reported as dry rot. The joists were allegedly not sealed properly.
No wonder it just sheared away like that.

Awful shame.