My musings over the precise causes of the timber frame fires last month have been noted by the UK Timber Frame Association (UKTFA). Yesterday, I was invited to talk over the issue with Stewart Dalgarno who works for Stewart Milne, one of our two timber frame giants, and who is currently chair of the UKTFA.
He reckoned I had underestimated the amount of timber frame apartment building that is going on. Stewart suggested that as many as 30% or even 40% of the medium-rise apartment market was now being constructed in timber frame and this accounted for 300 or 400 sites at any one time across England and Wales. As far as he was aware, there had never previously been any fire damage on the scale seen at Colindale last summer, since when it’s happened three more times, which is what caused me to raise suspicions that these events are not mere accidents, or even isolated cases of arson.
From the UKTFA perspective, the good news is that, thus far, developers have not been put off by the fires and that order books this year are healthily ahead of last year. It is one area where the speed advantages of timber frame really does have major attractions, because you can’t sell any part of an apartment complex until the whole building is complete, and this remains a strong pull for the scheme financiers.
He also went to great length to show that they were addressing the issue of fire hazards during the construction phase. No one is suggesting that medium rise timber frame is a fire danger once completed, but it does present some unique challenges whilst it is being erected. A report examining the causes of fires and methods of prevention is being finalised and should be published in the next few months, to be followed by a series of training seminars aimed at the construction industry.
It transpires that there is usually only a relatively short period during which a timber frame structure can be put to the torch. Once the walls and ceilings are lined, the building is effectively compartmentalised and the risk of fire is greatly reduced. So one of the key initiatives Stewart is suggesting is that, on sites identified as high risk, the lining process is moved up the critical path as far as possible so as to minimise the length of the time spent in the vulnerable panels open, insulation in phase. Ultimately, he sees the industry moving over entirely to closed panel systems where the linings are done off-site, effectively removing this period of added risk. It may well be that the recent fires will end up accelerating this process, which many already see as inevitable in the longer term.
In the meantime, attention is being paid to tightening up site management and security procedures and ensuring that timber buildings aren’t left open for many months, as seems to have been the case at Colindale. Reports on the circumstances and causes of the three more recent fires are still awaited. In the meantime, there is little more anyone can do but speculate.