The benefits of
combining off-site construction with external wall insulation (EWI) are
explored in a technical document produced by the British Board of Agrément in
conjunction with EWI specialist STO.
Aimed at specifiers,
contractors and end clients, the literature outlines the many benefits of
marrying the two solutions, from energy efficiency to time savings and
increased build quality to improved on-site health and safety.
“EWIs
and off-site construction are perfect partners when system selection, design
and testing are key considerations,” said BBA Test Services product manager
George Bailey, who co-authored the document with David Tyndall, STO Director -
Off-Site Construction Solutions (Western Europe).
“EWIs
can be applied to a wide range of off-site modular and panellised structures
including timber, SIPS, reinforced concrete and various steel-based options
that are proving increasingly popular for large multi-storey buildings.
“Durability,
thermal performance and long-term aesthetics rely on the performance of the
system as a whole…performance is achieved through multiple components working
together,” added Mr Bailey. "Therefore when considering design changes or
multiple external finishes, careful attention must be paid to the implications
these alternations may have on performance.”
The
literature also discusses technical elements to take into account, for example
the spacing of structural elements within each modular unit to accommodate
mechanical fixings and planning the EWI early in order to determine the entire
system’s performance through structural and environmental testing.
Manufacturers
offer numerous types of EWI, including EPS, XPS, mineral wool, PIR, PUR and
phenolic foam. This variety of material type and usage means there is no
standard method of testing and assessing systems; careful consideration is
therefore required to select from test requirements including fire and thermal
performance, watertightness, resistance to wind loading and structural
testing.
“EWI
products should be supported by robust testing carried out buy a
UKAS-accredited testing facility such as the BBA,” said Mr Bailey. “The work of
the BBA in establishing certification and testing parameters for EWIs has led
to European-wide regulation with EOTA and provided guidance to the UK
government.”
To view the document, visit: https://www.bbacerts.co.uk/uploads/cmsfiles/Industry_voices_STO_web.pdf
