Porch collapse
Encyclopedia
Porch collapse or balcony collapse is a phenomenon typically associated with
older multi-story apartment buildings that have wooden porch
Porch
A porch is external to the walls of the main building proper, but may be enclosed by screen, latticework, broad windows, or other light frame walls extending from the main structure.There are various styles of porches, all of which depend on the architectural tradition of its location...

 extensions on the front
or rear of the building. The collapses have a number of causes, including overloading due to excessive weight from overoccupancy (too many people). Overoccupancy can result from guests filling a porch at a party, from people seeking cooler breezes during a heat wave, or from people filling a porch while seeking shelter from the rain.
It may be from the weight of furniture/appliances, wading pools, or air conditioner compressors. After years of rain and snow, it may be from rotted wood. soil subsidence
Subsidence
Subsidence is the motion of a surface as it shifts downward relative to a datum such as sea-level. The opposite of subsidence is uplift, which results in an increase in elevation...

 under the porch foundation, rust of nails and fasteners,
and not being built to specifications required by modern day building code
Building code
A building code, or building control, is a set of rules that specify the minimum acceptable level of safety for constructed objects such as buildings and nonbuilding structures. The main purpose of building codes are to protect public health, safety and general welfare as they relate to the...

s. Many older porches were built before codes required them to be able to support a legally mandated load of so many pounds per square foot or meter, and porches are often not as sturdily built as interior structures.
The phenomenon is associated with older multistory apartment buildings with wooden porch
Porch
A porch is external to the walls of the main building proper, but may be enclosed by screen, latticework, broad windows, or other light frame walls extending from the main structure.There are various styles of porches, all of which depend on the architectural tradition of its location...

es. Architect Stanley Tigerman
Stanley Tigerman
Stanley Tigerman is an American architect, theorist and designer. He studied at Massachusetts Institute of Technology, the Chicago Institute of Design, and Yale University. After serving several years in the United States Navy, he assumed the role of draftsman and designer in a series of offices...

 said that in New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 one finds steel fire escapes, but in Chicago, the distance to alley
Alley
An alley or alleyway is a narrow lane found in urban areas, often for pedestrians only, which usually runs between or behind buildings. In older cities and towns in Europe, alleys are often what is left of a medieval street network, or a right of way or ancient footpath in an urban setting...

s behind multistory brick buildings encouraged the construction of wooden multistory porches.

While not an everyday occurrence, collapses happen often enough in Chicago that city building inspectors make a point of checking porches when making inspections. People have been killed and injured by collapses of wooden porches in other cities as well.

A Chicago porch collapse
2003 Chicago balcony collapse
The 2003 Chicago balcony collapse was a disaster that occurred on June 29, 2003 in the city of Chicago, resulting in the deadliest porch collapse in United States history. An overloaded balcony collapsed during a party in an apartment building, killing thirteen people and seriously injuring...

 during a get-together in the Lincoln Park
Lincoln Park, Chicago
Lincoln Park, is one of the 77 community areas on Chicago, Illinois North Side, USA. Named after Lincoln Park, a vast park bordering Lake Michigan, the community area is anchored by the Lincoln Park Zoo and DePaul University...

 neighborhood in 2003 killed 13 people. The weight of approximately 70 people caused the recently renovated porch of the 1890s vintage building to fail. The disaster inspired a 2005 episode of the ER television show. In June 2008, a third-story balcony collapsed in Ottawa
Ottawa
Ottawa is the capital of Canada, the second largest city in the Province of Ontario, and the fourth largest city in the country. The city is located on the south bank of the Ottawa River in the eastern portion of Southern Ontario...

, injuring six persons.

Deck collapse

A related hazard is the collapse of deck
Deck (building)
In architecture, a deck is a flat surface capable of supporting weight, similar to a floor, but typically constructed outdoors, often elevated from the ground, and usually connected to a building...

s built as outdoor extensions of single-family homes. When decks became a popular feature, construction practice did not keep up with the new fashion, resulting in many decks that were simply nailed to the side of their houses. The inherently weak connections were prone to failure, resulting in collapse with injuries and occasional death. In recent years building codes have been re-written to require direct structural connection to the adjoining structure, as well as cross-bracing to withstand sway.

High-rise apartments

High-rise apartment buildings are typically constructed from reinforced concrete. Many buildings have been designed with the concrete slab extending through the exterior walls to form balconies. Since they are relatively thin and unprotected from the weather, they are vulnerable to corrosion of reinforcing and potential collapse. Many buildings constructed in the 1950s and 1960's are undergoing repair or removal of such balcony structures at considerable cost.
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