January – 2017: One
of the star turns on Grand Designs recently was the spectacular
Treehouse project, built to meet passive house standards and set 40
feet into the forest canopy. Designed as a much loved home and also
to operate as a B&B, this blue-sky concept was naturally built to
the highest standards of sustainability and efficiency. Steel and
timber framed, with open-jointed timber cladding to blend into its
environment, the design demanded the very best from its building
envelope. Therefore, a range of DuPont™ Tyvek® advanced building membranes and accessories were specified to both protect the
structure during the build and to maximise airtightness and thermal
performance once occupied.
Considering the
location and style of the project, a key choice of membrane was the
highly specialised Tyvek® UV Façade option, a totally black
breather membrane designed to withstand exposure to sunlight. Fully
certified and rigorously tested, this option is ideal for ventilated
facades, allowing for the optimal combination of design freedom and
peace of mind. Fitted at first floor level directly behind the
elegant timber cladding of the treehouse, Tyvek® UV Façade™ will
maintain its high performance for many years to come. Fitting a
Tyvek® membrane in this way also protects the insulation from the
effects of windwashing – a process that is known to reduce its
performance and which can increase a structure’s U value by up to
80%.
At ground floor level,
Tyvek® Housewrap™ has also been applied externally to sit behind
the steel cladding and act as a secondary water shedding layer while
also diffusing moisture to the exterior. Watertight but naturally
vapour-permeable, Tyvek® membranes offer proven long term
performance in both these crucial functions. In each application of
the different membranes used here, all laps and penetrations have
been carefully sealed (correct installation and maintenance being a
key aspect of ‘performance as designed’) using UV Façade tape on
the exposed areas and Tyvek® tape to the areas protected by the
Tyvek® Housewrap™.
Internally, in order to
create an airtight seal and act as a moisture barrier, a systemised
partnership has been installed consisting of DuPont™ AirGuard®
Smart AVCL and Tyvek® Flexwrap to adapt to the more challenging
sections (together with the appropriate specialised tapes and
sealants.) As expected the initial airtightness results have been
outstanding, achieving an impressive figure of 0.32 ACH. DuPont™
AirGuard® Smart AVCL is both fully airtight and water resistant and
adapts its vapour resistance as humidity levels change, giving
buildings maximum protection against structural damage caused by
humidity.
Project owner Jon
Martin said “I was aware that there can be a big difference between
the finished product and the design on paper and I was determined
that the fabric of the building was correct. I knew that DuPont had a
full range of both internal and external membranes but this is
complimented with a wide range of accessories and tapes. These have
been essential for the building to achieve our goal of it being the
first passive tree house in the UK.”
DuPont™
Tyvek® is distinctive in many key ways, from its hi-tech naturally
breathable composition, to its renowned long term functionality. Both
DuPont™ AirGuard® and DuPont™ Tyvek® also come with expert
technical guidance and with the added peace of mind of a
comprehensive range of certification and full building regulation
compliance.
For
more information about DuPont™ Tyvek® in the UK please visit:
www.construction.tyvek.co.uk or call 01275 337 660 (087 922 2740 in
ROI)
