MMC 5541 48 Nov'15 cc

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Timber frame construction & the
risk of disproportionate collapse
A £1.4 million five-storey development of some 1,700 square metres, accommodating 23 individual apartments,
Aubrey Street in Herefordshire was a substantial project for timber frame specialists Taylor Lane.
Versaliner liner Sheets
Taylor Lane had been engaged by the
main contractor Speller Metcalfe, an
award-winning sustainable construction
company, with expertise in BREEAM,
Passivehaus and the Code for Sustainable
Homes.
The Project
The development, for client Matches Housing
Association, was to be constructed in close
proximity to several existing properties on
three sides. As is often the case with
developments where space and access are
restricted, off-site construction methods
present an attractive solution. Taylor Lane
specialise in manufacturing structural grade
C16 timber frame panels in a quality-controlled
factory environment.
Prior to Aubrey Street, Taylor Lane’s timber
frame panels incorporated an external
sheathing layer comprising, typically, either
OSB or plywood, depending on the application.
Indeed, the specification for Aubrey Street had
specified just these kinds of materials. Taylor
Lane decided that something more was needed.
The Challenge
The close proximity of the site to other
buildings and the risk of disproportionate
collapse meant that the consequences of
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accidental fire or even a possible arson attack
had to be taken very seriously. This is a
particular hazard faced by timber frame
construction projects. In fact, the Structural
Timber Association has launched several
initiatives to combat this phenomenon,
including detailed guidance.
According to the STA guidance, “All buildings
should have appropriate fire protection
designed and built-in as early as possible and
maintained throughout the entire construction
phase… For small or low-risk sites, the general
good housekeeping and standard approach
may be more appropriate… For other sites the
sub-division of the frame by fire-resisting
barriers must be considered as part of the
strategy for minimising fire spread risk during
construction.
The solution
Aubrey Street certainly didn’t fall into the
“small or low-risk” category. Consequently,
Taylor Lane opted to use Euroform’s Versaliner
instead of the specified OSB.
Versaliner is an A1 non-combustible Magnesium
Oxide sheathing board with excellent tensile,
compression and breaking strengths, and high
resistance to impact, moisture and insect
attack. Excellent racking resistance means it is
particularly suited to timber frame applications,
offering additional stability. The fact that
Versaliner is a “score and snap” materials
means it can be fabricated on-site without the
need for additional cutting equipment or can be
seamlessly incorporated into the streamlined
processes of off-site, factory-based
construction.
Taylor Lane worked closely with Euroform’s
technical team, taking advantage of their
expertise and experience in the complex area
of passive fire protection, to ensure Versaliner
was the appropriate product for this particular
application.
Duly satisfied that all their criteria had been
met and all their concerns addressed, Taylor
Lane began incorporating Versaliner into their
timber frame panels as part of their off-site
construction process.
A spokesperson for Taylor Lane said,
“Versaliner enabled us to safely build on a site
where fire risk was a significant factor. Without
it, we’d have struggled to proceed. We’re more
than happy with the product, it’s very
competitive pricing and ready availability.”
www.euroform.co.uk