Exterior Foam and Fire
severaltypesofnerd
| Posted in Energy Efficiency and Durability on
Another probable foam cladding fire – How much energy did this save?
Firefighters have battled a high-rise blaze in Milan that spread rapidly through a 20-storey residential building and poured black smoke into the air. Residents were evacuated and the city’s mayor, Giuseppe Sala, said there were no reports of injuries or deaths. He added that firefighters were kicking down doors, apartment by apartment, to make sure there were no residents left behind. The 60-metre (200ft) tall building, part of a recent development project, was designed to look like the keel of a ship and included an aluminum sail on its roof, which burned and fell to the street in pieces
““We were told that the panels that covered the building were fireproof, instead, they burned quickly like butter,” a resident told local paper Corriere.”
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
Considering more stick built homes burn down every day than this 200 unit building I'd say it's still a net positive. ;)
Bryce,
Like the Grenfell Tower fire in London it sounds as thought one in Milan was also caused primarily by a deep rain-screen cavity without fire blocking at the floors. I'm not sure that poor detailing or the use of the wrong type of foam can really be said to have implications for discussions about energy efficiency.
Well, the fire risk does play into a life cycle assessment of the impact of the choices.
That comes up all over. For example cheaply made CFL's performed poorly and contributed to a backlash against both the CFL's and energy improvements. So was the fault the CFL's or the lack of quality and longevity standards? Was mercury in the lamps overall a benefit or a harm?
Important to ask the questions, even if the answer still leads to the use of the mateial.
Mercury is a required part of flourescent lamps. They are a form of mercury arc lamps. It's not really a question of "was the mercury .. a benefit or a harm", since you can't have a CFL without the mercury part.
I think this is a case of the usual issue with many of these things, where people don't look at the big picture. CFLs always had lots of negatives, for example the coiled design is inherently inefficient due to what is known as "restrike" (light that comes out of the tube and does nothing but hit another part of the tube and make it hotter). Did CFLs use less electricity for the light they produced compared to incandescents? Yes, they did. Did CFLs fail too quickly and contain hazardous materials? Yes, they did. Were they a net overall benefit or not? I think probably not.
Commercial buildings are already required to be built far, far better than residential structures in terms of fire resistance. Remember that construction standards are not globally harmonized though, so what is allowable in Italy might be very different from what is allowable in the US. Even Canada and the US have differences, although usually they're pretty minor.
Bill
Bryce,
I don't know much about the Milan situation yet, but a lot of people in England should be in jail over their roles in the Grenfell tragedy. This wasn't some objective assessment of risk vs savings, and it wasn't due to mistakes or ignorance. There were deliberate lies about the wall assemblies' characteristics in a fire by various parties. These were criminal actions. Nothing to do with energy savings.
>"There were deliberate lies about the wall assemblies' characteristics in a fire by various parties. These were criminal actions. Nothing to do with energy savings."
I hadn't heard about that, but I completely agree with you. I have walked away from projects before when the owners want me to skirt codes or take shortcuts with regards to safety related things. There is really no excuse for actions like that.
Bill
From a fire safety point of view a 20 story apartment building is a very different set of problems than a 2 story home and they are built to very different sets of rules.
I do not believe US codes have ever allowed what was attached to that building in Britain.
Do I feel safe living in a home wrapped in foam covered with vinyl siding? Yes because I feel I live in a location with a low risk of wildfires. In a different location I would have likely made different choices.
Walta
I live in California where the definition of "area with low risk of wildfire" has changed :-(
Now a completely different question is on some buildings the R value per inch is very important. Others, not so much. When does that tradeoff lead to low fire spread materials being the better choice. Foam needs a lot of additive chemicals to not spread under such heat conditions.
Perhaps a good reminder that smaller (<= 3/4") wall rain screen gaps work fine and lower fire risk:
https://www.buildingscience.com/documents/building-science-insights/bsi-098-great-fire-london