Plans Proposed for Grenfell Tower Demo


Despite safety concerns, ministers from the United Kingdom are expected to formally announce their decision to demolish the Grenfell Tower later this month.

The announcement follows the release of engineering consultancy Atkins’ report—who was government-enlisted—on the state of the fire-ravaged structure.

Grenfell Background

During the early hours of June 14, 2017, a fire broke out in one of west London’s high-rises, the Grenfell Tower. The 24-story, 120-home apartment building had recently undergone a $12.73 million renovation that was completed in the spring of 2016.

At that time, the building was refurbished with a system of polyester powder-coated aluminum rain-screen panels, insulated exterior cladding and double-glazed windows, as well as a communal heating system.

In April of 2018, new investigations revealed that the cladding fitted on the Grenfell Tower had been downgraded before it was installed on the London high-rise. According to tests that BBC News uncovered from 2014 and 2015, a zinc cladding had originally been specified for the tower, but another brand was substituted for a savings of roughly $388,700.

The following month, former Prime Minister Theresa May pledged $517.9 million to cover the replacement of unsafe cladding for social housing blocks. Privately owned towers were left to figure out the replacements on their own, however.

As a result, many property owners passed the renovation charges to residents, which in some cases cost them thousands of dollars to make their homes safe again. Many more still have yet to even begin the renovation process.

Cladding Ban

In December 2018, the U.K. announced a ban on combustible materials. Former Housing Secretary James Brokenshire announced that under the new legislation, combustible materials would not be permitted in the exterior walls for new buildings more than 18 meters (59 feet) tall. Those buildings include homes, hospitals, residential care facilities, dormitories and other student accommodations.

That ban limits the use of materials to products that achieve a European fire-resistance rating of Class A1 or A2. The legislation also cleared up what exactly the government meant by an “exterior wall,” defining it as an external wall as anything “located within any space forming part of the wall.” It also includes any decoration or finishes applied to external surfaces, windows or doors; roof pitches at an angle of more than 70 degrees; balconies and devices for deflecting sunlight and solar panels.

The policy also prohibits the use of timber materials in the external wall of buildings in those parameters as well, which will stop many projects in their tracks, according to The Architects’ Journal, referring to developers using the cross-laminated timber construction method.

The materials ban took effect Dec. 21, 2018, but in December 2019 part of the ban was overhauled following a lawsuit by the British Blind & Shutter Association. (The court rules that the ban should not have included materials used on shutters, blinds and other products designed to reduce a building’s heat gain.)

In May 2019, the U.K.’s Ministry of Housing announced that it would foot the bill to replace the cladding on private residential high-rise blocks at the cost of roughly 200 million pounds ($258.9 million).

At the beginning of 2020, Housing Secretary Robert Jenrick put forth new measures with the goal to move “faster and further to improve building safety” adding: “The slow pace of improving building safety standards will not be tolerated.”

By June, an investigation by the U.K.’s National Audit Office revealed that the government doesn’t know how many of its estimated 85,000 buildings that are 11-18 meters tall are clad with the same ACM material that was used on Grenfell Tower.

At the time, the NAO said that remediation efforts could last until 2022 at least, as there were still 307 towers that had unsafe ACM cladding systems, with work not even having begun on 167 of them, and work complete on 149.

The office also noted that the Ministry of Housing, Communities and Local Government advised that the ACM cladding in question is unsafe on buildings of any height, which illuminated gaps in the department’s knowledge as it has admitted that it has no data on the number of buildings under 18 meters that have those cladding systems.

The report added that about 14% of private buildings had already been remediated, adding that the government paid out only about 0.7% of its promised funds for privately owned buildings. This is compared to the 33% it has paid out of its social housing cladding remediation fund.

Inquiry Updates

In February, the first—and probably only—person from Arconic testified in front of the Grenfell Tower Inquiry, revealing that the company sold panels that it knew were flammable because of costs.

Employees from Arconic as a whole made up much of the group that has refused to testify.

Prior to this and before the break, the Inquiry looked at several email chains and documents from Arconic. According to the inquiry reports, one email from a senior executive at Arconic (which made the polyrethylene core cladding panels) showed the official telling colleagues that the shortfall in the product’s fire performance was “something that we have to keep as very confidential.”

Natalie Oxford, CC-SA-BY 4.0, via Wikimedia Commons

In February, the first—and probably only—person from Arconic testified in front of the Grenfell Tower Inquiry, revealing that the company sold panels that it knew were flammable because of costs.

France-based Claude Wehrle, Claude Schmidt and Gwenaëlle Derrendinger—as well as Germany-based Peter Froehlich—worked at the manufacturer and were involved in selling Reynobond panels with a combustible polyethylene core for use on the Grenfell Tower.

The employees refused to give evidence, claiming they would open themselves up to prosecution under the “French blocking statute,” which is a French law that restricts people from sharing commercial or technical information to establish evidence in foreign courts.

The inquiry was originally launched back in 2017. Background on the inquiry phases and progress can be viewed here.

Plans to Demolish

Earlier this year, the U.K. government was reported to have published a letter informing the public that it was considering if and when the Grenfell Tower should be demolished, promising that “views of the community” would be taken into account.

Upon meeting with survivors and bereaved families, another plan was proposed: That the building be turned into a “vertical forest.” The proposal involved covering the structure with 72 species of plants, one for every person lost to the June 2017 fire.

While the idea didn’t stick, the Ministry of Housing, Communities and Local Government—which took ownership of the tower in 2018—assured families and survivors that the tower wouldn’t be torn down before the fifth anniversary of the blaze in June 2022.

In addition, an independent Grenfell Tower Memorial Commission was created to establish plans for a memorial.

Given the nature of the conversations and potential alternatives, it was indicated that survivors and bereaved families were “shocked” when reports revealed that the government was expected to formally announce the structure’s demolition plans.

The decision doesn’t come without reason, though. According to the report written by structural engineers from Atkins, the team advises that what remains of the Grenfell Tower be “carefully taken down” as soon as possible due to safety concerns impacting a nearby secondary school, among other structures in the community.

The report reads: “There is unanimous agreement and unambiguous advice from all the technical experts and engineers involved in the Grenfell project that the tower should not be propped for the medium to long-term but should be deconstructed at the earliest possible opportunity, with deconstruction commencing no later than May 2022.”

In an earlier report issued by Atkins pointed out that the condition of the tower had been worsening.

“The fire had the effect of spalling concrete from the underside of the floor slabs, most widespread from the tenth floor upwards, and also from many columns and areas of wall,” said the study. “As a result, the reinforcement is left exposed in many areas.

“As a result of exposure to the elements, spalling of concrete will continue, through the expansion of corroding reinforcement and absorbed water freezing in the winter months. Without this concrete in-place, the reinforcement becomes increasingly ineffective. Condensation forming on the structure surfaces exacerbates this deterioration.

“The rate of deterioration and expected life of the building is very difficult to quantify with any degree of certainty, however, what can be categorically stated is that the condition of the building is worsening,” it concluded.

Despite the team’s reports, National Federation of Demolition Contractors Chief Executive Howard Button told New Civil Engineer that it wouldn’t be straightforward to demolish the tower.

“It could be a very weakened structure,” said Button. “The rebar could be in a very bad state. The structural stability of the building must have degraded.”

Button went on to warn that because the fire took place four years ago, developing precise calculations for an effective explosion or implosion would be extremely difficult. The possibility of needing additional building fabric for ongoing investigations also poses an issue.

“It will most likely be a very controlled, top-down demolition,” Button continued. “The existing scaffold could be used, supported with propping, and a crane to lift debris out. Then remotely operated mini machines could be used by people a few meters away from the workface. Munchers and breakers would be attached to dismantle the building floor by floor.”

While it is likely that the tower will have to be taken down, an MHCLG spokesperson reported that no decision had yet been officially made.

“We know how important and sensitive this decision is, and no decision has been taken” they said. “Following important independent safety advice from structural engineers, we are engaging closely with the community as we consider the evidence including the safety concerns raised, and what the future of Grenfell Tower should be.

“We have now published this advice to ensure those most affected have access to the information that will inform a decision on the Tower, before one is reached.”


Tagged categories: Accidents; Demolition; EU; Europe; Fatalities; Fire; Good Technical Practice; Health and safety; Project Management; Projects - Commercial; Safety

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