Assembly in residential overloading collapses

[Frank]

Periodically we hear of aparment and home floors and decks collapsing during parties or most recently a religious gathering in Texas. We occasionally see ballrooms in single family dwellings that are a few thousand square feet. House churches are common and are protected by RLUIPA At what point or at how many people is it no longer a residential use?

http://www.khou.com/news/local/Garage-apartment-collapses-at-Katy-area-home-264773291.html

http://www.kentucky.com/2014/01/19/3042601/apartment-floor-collapses-during.html

http://chronicle.com/article/16-Students-Hurt-in-Balcony/96110/

http://www.nbc29.com/story/13177076/apartment-near-jmu-collapses

http://www.firstcoastnews.com/news/article/279012/4/Total-chaos-Floor-collapse-at-Seminole-Grand-Apartments-injures-55

 

[cda]

Not sure the whole story

Sounds like they were outside maybe on top of a garage patio?????

 

[Glenn]

I did not read the links, so I am responding to the general idea of using a bigger design load for a home than the standard 40 psf. I have researched and reviewed the idea of requiring decks to be designed to a higher live load. The following are my general opinions on the matter.

I think it's all about possibility vs. probability. The codes should address the minimum expected probability, not the rarely expected possibility.

I think the minimum probability is that folks will have mild parties at their homes. This is what the codes should prepare for. For those elaborate homes with ballrooms, the designer should anticipate the probable use for that specific house, and design it appropriately, as opposed to everyone having to build according to lifestyles of the few.

Designing something unique and unusual using a minimum standard intended for the common and ordinary is the mistake of the designer.

Just as the IRC recognizes the probability that bedrooms are minimally occupied and allow a reduced live load down to 30 psf, I could see recognizing that decks and large living areas will likely see more occupancy, and maybe...maybe...bump them to 60 psf... That said, 40 psf allows for a 200 lb person every 5 square feet. That's a pretty dense party, is it not?

I couldn't support 100 psf. That should be the personal, and responsible choice of the owner/designer for when they recognize their lifestyle does not fit in the IRC.

These are just opinions and thoughts. Good topic, Frank. I'd like to see some discussion.

 

[Frank]

Was more looking at what should be permissable uses/occupant loads in apartments and houses. Most of these incidents involved large 100 plus crowds in the house or apt.

None were specifically designed fo rthis use.

 

[north star]

= = &

All that designing to higher psf loads will cost "someone" more

money, and typically, ...IMO, the general housing market will

not bear those costs........Of course, not every housing market

is the same, but having [ some ] Residential builders design &

actually build to a higher; in this case, floor loads, might just

push them over what the market will bear [ i.e. - reduce their

profits ].

I had a discussion with some Simpson-Strongtie engineers

last year regarding using wind restraint devices, in an area

where they were definitely needed [ because of tornadic

activity ].......The local AHJ did not require the devices, nor

did the insurance companies [ for that area ].........The

Simpson-Strongtie engineers agreed that wind restraint

devices [ for that area ] could have lessened the amount of

damage to the affected Residential communities, but if one

Res. builder uses them; and increases their building costs,

how do they compete in the same market with someone who

cuts corners at every turn, and builds to what they can

get away with ?..........IMO, most AHJ's can only require

& enforce so much before [ some ] building contractors

start making telephone calls \ having meetings with "the

powers that be".

Essentially, the question is this, ...how is a level playing

field created and actually enforced to ensure that all

building contractors play by the same rules ?

My guess is that the insurance companies will be the

ones to require any improvements [ i.e. - higher floor

loads, ...actual installation of wind restraint systems

& devices, etc., etc., etc. ], ...or there could be another

coup by a select group of voters to have certain

requirements installed in the codes.



I'm going back down in the bunker now...



( * )

 

[cda]

What is wrong with a party for a few of your closest friends ???

Are you in American??? What next

 

[TheCommish]

100 people with an average weight of 200 pounds each on a 24x24' floor (my average garage) = 35psf and very tight, almost shoulder to shoulder

 

[ICE]

100 people with an average weight of 200 pounds each on a 24x24' floor (my average garage) = 35psf and very tight, almost shoulder to shoulder

It should have held up.

The reporter said "it was rated for six people and there were forty which is overloaded by a factor of seven." Well she was sorta cute and a girl so that makes it alright.