Sunday 10 July 2011

Glass & Imperfections - Report Those Unsafe Windows


Woman's leg is cut off by falling sheet of glass: A 19-year-old woman's lower leg was cut off by a shard of falling glass from a commercial building yesterday in Hangzhou City, capital of east China's Zhejiang Province. The woman, Zhu Yiyi, was reported in stable condition but faced the likely permanent loss of part of her left leg. The blood vessels and nerves were seriously damaged and "almost impossible" to be reattached, said Wang Jialing, deputy of the Sir Run Run Shaw Hospital. Zhu remained in a coma in the intensive care unit after four hours of surgery. A 1-meter-long sheet of glass hit Zhu from behind on her knee as she and a co-worker walked near the 23-story Qingchun Development Building about 8:30am, her co-worker surnamed Wang said. Wang escaped with only minor injuries. Wang said the two were on their way to work at a nearby steel company.
Zhu, a native of east China's Jiangxi Province, has worked for one year in the company and was often praised as being diligent. A witness surnamed Tian said, "I heard a boom and saw her lying in blood, fainted. I could see her white bones." The piece of falling glass may have been one pane of a double-paned window on the 21st floor of the building, said the building's Binjiang Property Management Co. Some witnesses said the window had recently been changed. A company spokesman surnamed Shao said workers checked and maintained the windows, which were installed nearly five years ago, every month. He denied the company was responsible for the accident, saying the floor was a private area belonging to a new tenant, a paper-making company, reported Zjol.com.cn, a local news website portal. Shao said the company will corporate with the police investigation and has covered medical bills for Zhu so far. A spokesman for the paper-making company said the firm had just moved into the building and did not know why the accident occurred.

Window Pane Falls From Top Of Canary Wharf Tower: A pane of glass plummeted from one of the UK’s tallest buildings yesterday. Part of the logo from the Norman Foster-designed HSBC Tower fell over 150 metres onto the building’s western entrance, closing North Colonnade while inspection took place. There are no reports of any injuries. In a slightly odd statement, an HSBC spokesperson told reporters “We don’t know why it fell out, but we are confident there won’t be any more coming out. 

A crack is seen on the rear window of a car that was hit by glass that fell from the 46th floor of a high-rise in Pudong's Lujiazui area. Dozens of cars were damaged yesterday after pieces of glass from a broken window fell from the 46th floor of the One Lujiazui office tower in Pudong New Area. The falling glass shattered front and rear windows as well as sunroofs and dented cars about 1pm, according to a parking lot security guard. No one was hurt. But witnesses said it's happened before and they were worried that next time someone would be seriously injured. Employees of Union Trust Ltd, which is on the 46th floor, said a janitor found a broken window in an idle office room yesterday morning. The firm reported the case to the property management center, which sent people to repair it. However, the window, which was about 3 meters by 1.5 meters, fell because of the strong wind and the glass fell onto the cars below, workers said. Several office workers said this was not the first time glass had fallen from the building. Li Haoqing, an office worker in the building, was stunned to find his car was damaged for the second time. "My car was smashed in a similar accident last year," Li said. China Pacific Insurance Co Ltd employees were on the scene speaking to the owners of the damaged vehicles and collecting evidence. A CPIC worker surnamed Zong told Shanghai Daily that there was at least 30 damaged vehicles.

Tank fixed, aquarium back in swim: Sea creatures and their fans are content again, as the New England Aquarium has reopened after a crack in its main tank was temporarily repaired, said Tony LaCasse, spokesman for the facility. Early Thursday morning, staff discovered the spiderweb-like fracture on the inner pane of a 2-inch-thick laminate window, comprising three separate sheets of glass. The cylindrical tank contains a coral reef and more than 750 sea animals, including Myrtle, the 560-pound sea turtle. The aquarium said Thursday it was draining more than 6 feet of water out of the 23-foot-deep tank to make the repairs. “The neighborhood was a little bit more crowded last night,’’ LaCasse said. “But during the repairs they did well.’’ A custom piece will be ordered to permanently replace the cracked section, he said. But for now, it is back to business as usual in the 200,000-gallon tank. “Everyone is back to their normal spots and happy,’’ LaCasse said.

Proper window seals are important: Poor planning and not condensation can be the enemy when it comes to effective building envelopes. That was the one of the messages at the seminar,"Water and Buildings is a Recipe for Disaster, or Not," at Buildex Edmonton. The discussion covered several aspects of building envelope planning and implementation, and how a lack of them can lead to drastic consequences down the road. Tang Lee, a professor with the Faculty of Environmental Design at the University of Calgary, showed how condensation can translate into major repairs over time. “Condensation by itself is not a problem, if it’s on a material that doesn’t deteriorate, such as glass,” Lee told delegates. “You see condensation on a window. No problem. But if that condensation streaks down onto the window sill, that’s when you have a problem because the window sill, if you are using wood, is going to leak through the window sill, rotting the wood, (from) that wood, into the wall. And, you don’t know what’s going to happen until it blisters through.”
Lee said he recommends not using wooden windows unless the humidity can be controlled inside the building. Instead, the professor advocates vinyl or metal-clad windows, something he recommended to Canadian Housing and Mortgage Corporation more than 20 years ago. “They started doing that and they saved a lot of problems,” he said. But, regardless of the type of window used, Lee explained that builders need to be aware of the imperfections in windows and that the manufacturer’s claim that 95 per cent of the products coming out of the factory are perfect. “If you got 95 per cent in my class, you’ve got an A plus, but 95 per cent from a window manufacturer – that’s not good enough,” he said. “You’re going to get five per cent that’s leaking. If you’ve got a hundred windows in a condo or high rise building, five of them are leaking. You can’t tolerate five. You can’t tolerate one.”
However, the professor estimates that the true percentage is more likely to be 10 to 15 per cent due to shipping and handling of the windows from factory to job site as well as the handling of the windows during installation. “You cannot rely on that window to keep the weather out,” he said, adding that contractors need to wrap the sill to prevent moisture from getting in. “You need to wrap the sill with a waterproofing membrane, so when the windows leak some day in the future, it’s not going to damage your wall. It’s a backup, a second line of defence,” he said. Lee explained wrapping the sill with a building paper, tie back or any other material used as sheathing does no good because the material is not long lasting.

Cracks in the city of glass: Chris Vollan loves his box made of glass in the sky. From his eighth-storey apartment on the north shore of False Creek in Vancouver, the floor-to-ceiling windows on two sides make him feel as though he is living on a viewing platform above the city. “It's a huge panorama and it makes my whole place feel bigger,” says Mr. Vollan, an engineer who lived in 19 different homes before arriving at Concord Pacific's Cooper's Point tower. His glass-box lifestyle is shared by many Canadians in urban centres. It was born in Vancouver – or as Douglas Coupland renamed it, “The City of Glass” – in the post-Expo '86 boom years and then popped up in Toronto about a decade ago.
But the ascension of the clear glass tower, first seen in Chicago in the 1950s, is slowing. Architects and buyers have complained of how boring glass towers have become. Planners and sustainability experts wring their hands about the lack of energy efficiency – glass, after all, is the poorest insulating building material around. And soon, new codes with heightened environmental standards will force builders to limit the amount of clear glass on the exterior.
“Absolutely there's a shift,” says engineer Peter Halsall, whose Toronto company, Halsall Associates Ltd., has built glass buildings, fixed glass buildings and lobbied for modifications to the glass-only building. Office builders are leading the way, he said, as tenants demand more energy efficiency. Residential builders are following as they are pushed and pulled by a chorus of planners, engineers and the public. At the city of Toronto's design review panel, there's a conscious effort to encourage architects to move beyond glass. “Successful cities are made up of many different materials,” says panel chair Gordon Stratford, an architect and vice-president at HOK. “If you don't get those different materials, you don't get the richness we love about cities.”
In Vancouver, concern about the energy and design problems of glass towers is even stronger. “They are very inefficient,” says David Ramslie, the city's sustainable development program manager. Not only does glass transfer heat and cold much more than other materials – making buildings more expensive to cool in the summer and heat in the winter – but builders have typically built glass towers with the same materials on all four sides, even though the impact of the sun is far more severe on the south and west. Scot Hein, head of the city's urban design studio, has these concerns and more. Glass towers have tended to have a monotonous style because of the limited range of construction methods in the early days. In newer neighbourhoods they quickly became repetitive and boring.
Architects have also been stuck on one particular glass tint – seafoam green – because it is cheaper than clear glass or other tints. In Vancouver, where the view of the mountains, sea and city is highly valued, maximizing that view was job one for architects and marketers. Glass didn't just allow them to sell standard units for more money – it also allowed them to builder smaller units that didn't feel quite as small. As well, glass technology continued to advance and developers discovered it was actually the cheapest way to build. For one, glass is cheaper than other materials. Second, it's cheaper and faster to install.
David Pontarini, the Toronto architect working on the new, glassy Shangri-La tower in the city, notes that all-glass means the developer doesn't require two or three trades – the brick people, the steel people, the window people –to co-ordinate. With the new concrete towers, glass can just be clipped on after each floor is poured, allowing the builder to enclose the space almost instantly. But pressure from buyers, architects, planners, engineers and the public for more variety and less energy consumption is having an impact. In Vancouver, architects have turned to bold splashes of colour. James Cheng's Spectrum building for Concord, with its large metal bars and frames in primary colours, was one of the first. Others nearby have incorporated big blocks of burnt orange or terracotta, blocks of red, or even bands of metal or stone.
Ultimately, though, the biggest driver of change is likely to be the building code. Concord Pacific's Toronto buildings now are different from those built in the earliest phase, said senior vice-president Peter Webb. They used to be 65 per cent clear glass, 35 per cent spandrels (exterior sections usually of painted glass with insulation behind). Now it's 50-50, to meet new requirements in the national and provincial building codes. As well, the company has provided small architectural “eyebrows” over windows. “We know we need to reduce the heat gain so the cooling system isn't burning as much energy,” said Mr. Webb.
Vancouver is considering even stricter standards, requiring all buildings in rezonings to meet a strict LEED Gold standard. Still, no one thinks the glass tower is going away completely. Builders will use more spandrels, look for better types of glass, introduce touches of other materials for variety. But they're not going back in history, says Mr. Pontarini. “The day of the old stone or brick building is gone.”

Why is it easier to crack glass if you make a scratch in it first? Why is it so much easier to crack a piece of glass or tile if you make a scratch in it first? This is an interesting bit of physics. Indeed, it is quite amazing how even a rather small, superficial crack will dramatically change the strength of a brittle material. Let’s think about a glass rod, for example. The same idea applies to tiles, or similar objects, like glass tubing. In the glass rod, the atoms attract one another via chemical bonds — that’s what holds the rod together. If you pull both ends, you have to break a lot of bonds to snap the rod cleanly in two. If there’s already a crack, the results are different, depending on its size.

Workers armed with suction cups have removed more than 600 of the 1,000 glass panels on balconies at the W Austin Hotel and Residences as engineers continue to look into what caused eight of the panels to shatter and fall 20-plus stories in three separate June incidents. Wood paneling is being used to temporarily enclose the balconies until a cause is found, clearing the way for new glass to be installed. In the interim, the downtown hotel at 200 Lavaca St. remains closed. "A comprehensive investigation continues, and we will provide updates on our progress in the coming days," Beau Armstrong, CEO of developer Stratus Properties, said Thursday.
Theories abound, some pointing to intense heat, wind, imperfections in the glass or even falling debris. A report by Curtainwall Design Consulting, which investigated the initial incident on June 10 at the request of general contractor Austin Commercial, indicates the glass failures could have been caused by grout and concrete that came loose. The engineering firm said it found evidence that high-strength grout fell from an overhanging slab on the 27th floor and onto the top of a glass railing two floors below. The report continues to say that falling debris "could likely damage the top edge of glass causing catastrophic failure."
Because of the heat strengthening process tempered glass undergoes, industry experts say, the edges are the weakest part of each pane. And unlike the edges of the glass railings at the W, which were uncovered and exposed, they are often protected by metal framing or some other material. Mark Meshulam, a consultant contacted this week by the American-Statesman, said the tempered panels could potentially have manufacturing flaws, causing the glass to "pop" when it's exposed to heat.
U.S. Railings, which Stratus said designed, fabricated and installed the building's railings, directed media inquiries to the developer, as did the glass manufacturer, XYG, or Xinyi Glass. A spokeswoman for BOKA Powell, one of the architectural firms that worked on the building, declined comment Thursday. While work continues, sidewalks surrounding the W and portions of several adjacent streets remain closed, creating significant traffic tie-ups.
A guest died at an Atlanta W in late May after falling out of a 10th-floor window. A friend was seriously injured. A lawsuit alleges the glass that shattered, allowing the women to fall onto a sundeck below, had been installed improperly. Another window at the W Atlanta-Midtown reportedly broke last year after what the Atlanta Journal-Constitution calls "almost incidental contact." The incidents in Atlanta, Austin and Washington do not appear to be related.

Falling Glass Causes Death of Florida Construction Worker: A construction worker in Key Biscayne, Fla., died yesterday after hurricane-resistant glass and other materials fell on him while inside a container truck. According to news reports rescuers had to cut a hole into the side of the container to try and reach the trapped worker; however, he is reported to have died at the scene. According to the report, “the man was delivering windows to a vacant home and was in the back of the 18-wheeler when the two glass windows weighing 3,000 pounds fell and crushed him, officials said.” Another worker, also reported to have been in the truck when the scaffolding and glass shifted, is said to have suffered an arm injury.

No comments:

Search This Blog