Roofing

Flat Roofing
Tales from the Roof
Gathering Evidence of Roofing Failures
Stewart Little, Chief Executive Officer of IRT Surveys
We found significant areas of saturated insulation close to the leaking areas reported by
the tenant. We were able to track the saturated insulation back to air conditioning units,
installed without consent, by a neighbouring tenant. The images were used to inform and
guide the repair and replacement of the affected areas, and the adjacent tenant was
charged with the repair. This was a conflict that had been going on for nine months
before the survey was commissioned. The imaging settled the argument very quickly. The
visual nature of the images provides unequivocal evidence and therefore confidence to all
parties.
Roofing is probably the most important element of any building's fabric.
Keeping a roof over your head is so vital, it is difficult to comprehend why
anyone would not put it first and foremost on their wish list for any new
build or refurbishment. Why then, do people specify a cheap roof - go with
the lowest tender, skimp on insulation and maintenance - only to invest
heavily in the office furniture?
The answer has to lie in the fact that our client's client - and staff - seldom
visit the roof, but they do value a nice desk and chair. Complaints about the
roof only come when it's too late; when water is literally dripping onto the
lovely desks below. Many clients are aware of this of course and take a
long-term view of the building’s lifecycle and operational cost, but even
then, so much emphasis is put upon the budget and life span that the poor
old roof is overlooked. Ironically, if it were literally overlooked, they would
care more!
A real challenge is commercial reality. Some 85 per cent of office buildings
in London are rented. This means the owner and occupant have vastly
different objectives. The tenant isn’t allowed to change the fabric and
doesn’t want to invest in the building when the owner ultimately benefits
from the investment. Conversely, the owner of the building doesn’t really
care if the tenant’s desk has a few drips now and again. It doesn’t affect
them.
This creates a conflict that must be resolved with as little cost to each party
as possible. So what happens? They both hire RICS surveyors and the bills
start to rack up. After a bit of back and forth, differing opinions and
conflicting reports – many surveyors choose to explore a technology called
infrared thermographic surveys – IRT for short.
IRT surveys have been around since the 1950s and became a recognised
roof surveying method in the early 1990s. The technology has moved on
significantly since then, becoming more affordable and more accurate each
year.
Exposing the deficient and dodgy
Thermographic technology now has an established place in the surveying
armoury, being utilised to reveal deficient work and expose dodgy
contractors, as a recent case proved.
The location and client in this case cannot be disclosed for obvious
reasons, but the facts of the project illustrate how the technology enables
gathering of evidence and the speedy resolution of disputes. Essentially we
surveyed a 3000m 2 roof in the south east of England for a blue chip
surveying practice. The images very clearly revealed problems across the
entire roof and our client decided to go for a complete strip and renew. We
seldom hear anything back from clients after the initial instruction, but in
this case we were asked to return and conduct an after-survey.
The results were shocking.
Having paid for a complete strip, what the client had received was a partial
strip and comprehensive overlay. The contractor in question was adamant
The dark blue and purple rectangle is new PUR
insulation. Everything else is a two layer overlay of a
saturated fibreboard system.
he had delivered a completely new roof and that the
persistence of leaks must, in fact, be down to the cladding
system. He had actually provided our client with a quotation
to replace the cladding.
Within seconds of arriving on site, we were able to show
exactly where the strip ended and the overlay began. The
client, owner and contractor were all present, in the late
evening, to witness the survey being carried out. On the
evening, the contractor was asked to cut core samples
wherever we directed him. We were able to prove, beyond a
shadow of doubt, where corners had been cut. The first core
revealed brand new polyurethane insulation below two
layers of felt and sitting nicely on a quality vapour barrier.
200mm away, however, we found two layers of felt on top
on the old system, complete with saturated fibreboard. This,
thankfully, remains an isolated case for us. Only once in 14
years have we uncovered something quite so brazen. We
haven’t surveyed every single roof of course, but statistically
it is a very rare event.
Solving the case
In another case, at the other end of the country in Glasgow
this time, we surveyed an office block for a client who had a
leaking roof. The office’s tenants were complaining about
leaks below what should have been an excellent flat roof
that was relatively new, of a decent specification, laid by an
approved contractor, and less than three years old. So what
was going on? No details, penetrations or upstands could
be found in the vicinity of the leak.
This anomaly wasn’t quite as instantly obvious as the case
mentioned above, nor was it a rare occurrence of fraud. This
time it was something far more common – a far more every
day problem.
One of the air conditioning units, installed without consent, which caused the roof to
leak.
The blue, yellow and red clearly shows warmer areas caused by
trapped moisture and damaged insulation.
The flat roof harbouring hidden problems
The flat roof showing water ingress around the air conditioning unit and consequent
saturated insulation.
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