Fires burning across parts of the UK last week spread in the same way as those that caused the Great London Fire and would have been far worse with stronger winds, a fire expert has said.
Fires in Wennington, Uxbridge and Erith destroyed 41 properties last Tuesday as temperatures topped 40C to make it the UK’s hottest day on record, and fire services had their busiest day since the Second World War.
Guillermo Rein, professor of fire science at Imperial College London, said strong winds played a major factor in the spread of the 1666 fire, which lasted four days and ended when soldiers blew up houses to create firebreaks, and the strong east wind died down. .
“As he blew, the [great fire of London] it was completely unstoppable,” he said. “So let’s put it that way. Tuesday could have been even worse if we had more wind.” Gusts reached 14 mph last week, barely above average.
“Obviously, the London of today is much safer than the London of 1666. But this was an urban fire, where the fire spreads from house to house, helped by the vegetation. This is what happened in 1666. This happened on Tuesday”.
After the fire of 1666, most of London’s wooden houses and churches were rebuilt in stone, and climate change means that builders, architects and the public must now also change their approach to safety against fires, Rein and other experts said.
Most fires are started by people, usually accidentally, through sky lanterns, or by barbecues or bonfires that are thought to have gone out but are still smoking.
Anyone with a garden should be aware of how fire can spread to their home, Rein said. A compost fire can spread to a wooden fence, which can then light an overhanging tree and, in turn, the roof of a house.
The Great Fire of London depicted in a Dutch school painting. Photograph: Imagno/Getty Images
Windblown embers are also dangerous: the 1666 fire spread to different areas when embers landed on other houses.
“Tiles are tremendously fire resistant,” Rein said. “But if they are not maintained well, embers can fall through a hole and the structure of a roof is made of wood.”
Paul Bussey, a member of the Royal Institute of British Architects’ expert fire advisory group, said: “Our legislation doesn’t cover anything about external fires spreading from one building to another. We’re not used to that. But we really have to start thinking about it.
“When it’s also a zero-carbon economy where we’re trying to use more wood and less concrete, it’s a tough ask.”
Green living walls, such as one in London’s ExCeL building, could be considered a vector to spread a fire, he added. “We need to get to a stage where we can reconcile all these conflicting issues in a proportionate way.”
Australia’s Bushfire Building Council last April released designs for a “disaster-resilient house” called the Fortis aimed at allowing Australians in areas prone to bushfires, cyclones or floods to evacuate but return to his house intact.
Kate Cotter, the body’s chief executive, said the designs included a streamlined roof to withstand cyclones and metal mesh screens to protect windows from embers and heat. Retrofitting existing homes is also an option, depending on the type of building, he added.
“Ninety percent of our homes are not resilient to local disaster risks,” Cotter said. “The classic UK house has many strengths – brick and stone are strong and durable. The most important thing is the detail, looking at where we have chimneys, vents, weep holes, exhaust fans and sealing them with screens of mesh so that the embers cannot enter.
“People should definitely look at toughened glass – double glazing is usually not fire resistant, but toughened glass is.”