November 2018

Project Focus
TORCH SYSTEM SHOWS THE WAY
Langley Waterproofing Systems delivered its TA-20 torch applied system to the Girdlestone
Estate in Islington, London – resolving the water ingress issues. The success of this
refurbishment project was recognised at the 2018 Roofing Awards, with the project winning
the Reinforced Bitumen Membranes category.
During the 1990s, a shallow pitched metal
butterfly roof with in-built gutters was
installed onto all Girdlestone Estate
properties. However, defects in the roof’s design,
combined with the age of the system, led to
leaks, affecting both the homes and their
occupants. Despite continual repair work, issues
with the roof persisted. Islington Council therefore
decided that a full replacement of the 3,600m²
roof would need to be undertaken, in order to
permanently fix Girdlestone Estate’s failing
system.
Informed decision
In order to make an informed decision about the
type of roofing system that should be installed,
Langley, along with its approved contractors,
conducted a full assessment of the existing roof.
The team removed a section of the roof to inspect
its state and decipher the best way of approaching
the project – they discovered that the mineral
wool insulation within the old system was
completely saturated and needed to be replaced.
Langley’s TA-20 – a premium high-performance
torch applied SBS elastomeric membrane for
warm roofs – was the chosen solution. Due to the
water damage found on the original roof, the new
system had to be carefully considered to ensure
that no further issues would ensue. The TA-20,
which is part of the Langley Parafor range, is
durable, yet flexible and the heavy-duty polyester
composite metal lined vapour barrier provides a
robust, watertight layer, preventing water damage
and any leaks to the below structure, whilst the
works are ongoing.
The system’s 40 year life expectancy was a key
consideration in the decision for TA-20, along
with its certifications; the membranes used for
TA-20 are covered by MOAT 31, the assessment
for Reinforced Homogeneous Waterproof
Coverings of SBS Elastomer Bitumen, and the
Parafor Solo Cap Sheet, which is the outer layer
of the TA-20 system, achieves a “resistance to
damage” rating of R4 under MOAT 31. The
system also carries a 20 year independently
insured guarantee for both materials, design and
workmanship.
Gary Chapman, Group Leader, Capital Programme
Delivery at Islington Council, said: “The
Girdlestone Estate has been a priority for the
council and we knew that Langley – working with
our service provider Mears – could be trusted to
work closely with our technical team to carry out
an extensive survey to reveal the underlying
issues with the roof.”
Work on the roof took place as part of a broader
refurbishment of the Girdlestone Estate, with
Mears Group Plc carrying out the external works
at the same time. The project as a whole was
completed on a tight time schedule, which made
lead times a major challenge for Langley.
Langley was able to put a plan in place and keep
the work running to schedule and without
problems. Langley used the initial block, as well
“The team removed a section of the roof to
inspect its state – the mineral wool insulation
within the old system was completely saturated”
Above: The Girdlestone Estate, Islington project.
as its extensive knowledge of roof types across
London, to gain calculations for the tapered
insulation, rooflights and outlets. The team could
then create these elements for the remaining 19
blocks ahead of time. This ensured that the
construction team could remove the existing
metal butterfly roof and instantly replace it with
the new TA-20 system, without the need for a
temporary solution.
Rolling programme
The team also utilised a rolling programme, which
enabled communication between the client and
contractor. This was vital for the success of the
build and allowed for the original roof to be
inspected on the day that it was being replaced.
The team was then able to make adjustments
without causing major disruption to timescales.
David Hodgson, Executive Managing Director at
Mears Group, added: “With such a challenging
project, Langley’s support throughout the
refurbishment was invaluable and the solution
they provided will ensure that the estate’s roofs
are protected from any future problems.”
Contact Langley Waterproofing Systems
01327 704778
www.langley.co.uk/
68 TC NOVEMBER 2018