BLUE ROOF DESIGN CONSIDERATIONS
AFTER BS6229:2018 UPDATE
Landscape & Urban Design spoke
with Bauder’s technical director,
Nigel Blacklock and Chris Roddick,
green and blue roof product manager
for Bauder on the changes in the
BS6229:2018 update that impact
rooftop water management solutions.
The BS6229:2018 – Flat Roofs with
Continuously Supported Flexible
Waterproof Coverings update was
published in November, overriding the
2003 edition.
Nigel can you outline the updates to
BS6229 that relate to blue roofs and
why they came about?
Nigel: The main considerations in the
update relate to structure, drainage
and thermal performance. A blue roof
is a good example of a new technology
that has come along in the last 15
years and needs consideration.
Chris, tell us about Bauder’s rooftop
SuDS system, BauderBLUE
Chris: BauderBLUE is a blue roof
system which attenuates heavy rainfall
and controls its discharge over a 24-
hour period. Calculations are made to
So, how will the revisions in
BS6229 update impact the design
considerations for a BauderBLUE
roof?
Chris: The 2018 update clarifies and
reinforces the meaning of a zero falls
factor in the site location, catchment roof used in most blue roof systems.
areas and discharge rates from other A zero falls roof is defined as having
elements of the site to ensure that the no more than a 1:80 fall, but more
water run off during storm conditions importantly the roof must not have
meets drainage requirements of local any back falls away from outlets.
planning authorities. This will mean all back falls must be
corrected with localised latex screed
or additional outlets.
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Landscape & Urban Design Issue 37 2019