The advice has been produced by the Health & Safety Executive, in conjunction with the Structural Timber Association (STA), which represents the industry’s manufacturers and suppliers.
The HSE has acted in the wake of serious incidents where fires involving timber frame structures under construction have affected neighbouring buildings.
“Evidence from recent HSE inspections indicates that the risk of harm to occupants of neighbouring buildings from fire during the construction phase is not always effectively managed…” the HSE says, “and that not all duty holders understand what is required of them.”
HSE head of construction sector & policy Simon Longbottom has written an open letter to all parties involved in the design, specification, procurement and construction of timber frame structures. He reminds them that Regulation 11 of The Construction (Design and Management) Regulations 2007 (CDM) requires risks to be designed out as far as is reasonably practicable. This duty is imposed on anyone who makes decisions affecting the design, including architects, structural engineers, clients, suppliers, principal and other contractors and even those involved in the planning approval process where they specify particular construction methods or products.
The primary legal responsibility for assessing off-site fire risk rests with those making design and procurement decisions before work starts on site, the HSE says. Designers and manufacturers of timber frame structures have duties under CDM Regulation 11 that cannot be passed on to the principal contractor. Risk should be designed out as far as possible and information about residual risk must be passed to the principal contractor, who is then obliged to consider and manage risks arising from the activities under their control at the site stage.
There is also HSE-approved guidance on assessing fire risk and its impact on neighbouring properties in the STA publication Design guide to separating distances during construction.