Increased Importance of QA Inspections of Low-Slope Roof Assemblies

The quality assurance (QA)
inspection of a low-slope roof
system is, in most instances,
the last line of defense to
ensure that a roof assembly is
properly installed to allow for
a maximum level of effective service, past
the duration of any warranty or guarantee
issued by the roof system manufacturer.
The intent of the QA inspection is to ensure
that the owner receives at least what he is
paying for, which is the optimal scenario,
as it is all too common for an installed roof
assembly to have materials and details
that are of a lesser quality than were specified.
In order to justify the expense of QA
inspections, such work must add value to
the project in the form of a higher-quality
installation that should allow the owner to
realize long-term effective service from the
roof assembly. Even a roof system installed
to marginal or slightly diminished standards
will work for 10 to 15 years; however,
the value of an effective QA inspection is
realized when the owner obtains 25 or more
years of effective service life from a roofing
system. Properly performed QA inspections
go a long way to ensure minimum standards
of the roof system manufacturer are
met, as well as enhanced specifications and
details that may have been designed by a
roofing professional.
A series of factors combine in the current
low-slope commercial roofing industry
to make it difficult for an owner to obtain
an optimal roof installation without a QA
inspection. On the positive side, the overall
quality of low-slope roofing systems and
materials has continued to improve over
the past few decades. Unfortunately, this
is being offset by the overall lower quality
of skilled labor, which continues to erode
for a variety of reasons. Not since the days
when most new roof systems involved field
fabrication of built-up roof assemblies have
QA inspections had such an influence on
the overall longevity of installed roof systems.
The older BUR systems required close
monitoring of the bitumen temperature at
the kettle and mop cart prior to mopping,
and those temperatures were taken with an
analog-style thermometer that required the
tester to be up close to the bitumen.
Older BUR assemblies also required
monitoring of the rate of interply bitumen
being applied and had also to ensure that
the rolled-out felts were broomed in without
being walked upon and that there was
an adequate amount of bitumen bleed-out
on every felt. In short, QA inspections performed
a very important function that had a
direct correlation with the optimal length of
service obtained from a roof assembly.
As the popularity and market share of
single-ply roofing systems grew (with, in
most cases, more comprehensive warranty
coverage and use of prefabricated membrane
and flashing materials), many owners
elected to reduce and even eliminate the cost
of QA inspections of roof installations on the
premise that the roof system manufacturer
performed a final inspection prior to issuing
a warrantee or guarantee. Such a thought
process is flawed and short-sighted, saving
limited funds in the short-run but having
the potential to create a significant expenditure
in future years, as a poorly installed
assembly requires premature replacement
or repair due to widespread leakage and
system component failures.
While final inspections are performed
by tech reps for roof system manufacturers,
in most instances, they are quick and not
as comprehensive as the owner and most
design professionals would like. Such quick
final inspections—if performed at all—are
more a function of the business side of the
industry and a prerequisite to issuance of
the warranty or guarantee. The tech rep
inspection is typically rushed, allocated
two hours or less, which is not sufficient to
review each membrane seam, penetration,
and perimeter flashing. This allows portions
of the system to remain in service outside
the designed specifications.
Such is not typically a deliberate attempt
to allow the specifications to be compromised,
but a result of a rushed inspection.
The scenario plays itself out constantly and
is allowed due to the fact that most industry
professionals, including the manufacturers,
know that even a marginally installed roof
system will provide adequate service during
the 10- to 15-year period that is covered
by the warranty. Covering the repair cost
for a few leaks on a less-than-optimally
installed assembly is considered by some to
be a function of the business and less costly
than training additional tech reps to ensure
they have sufficient time and training to
perform a truly comprehensive final inspection—
let alone periodic inspections. It is not
uncommon for a recently installed low-slope
roof system to be subsequently inspected
well after the roof was installed, as a function
of a maintenance inspection, and to
find a series of substandard details and
2 4 • I n t e r f a c e S e p t e m b e r 2 0 1 5
Increased Importance
of QA Inspections
of Low-Slope
Roof Assemblies
By Marc N. Boulay
applications that should never have been
passed by any tech rep performing a final
inspection. These include seam wrinkles,
poorly sealed pitch pockets, cold or burnt
welded thermoplastic seams, inadequate
butyl tape exposed on EPDM assemblies,
dry laps on modified-bitumen systems, etc.
To be fair, some of the substandard
details encountered on newer roof systems
after the warranty has been issued
are marked on the roof for the contractor
to address, but without a follow-up final
inspection, we find most such items are
never taken care of. Rather, the roofing contractor
relies on the warranty to address the
issue if leakage occurs at the substandard
detail. If a leak develops within the first few
years, he will repair at no cost, so there is
not a huge emphasis on returning to fix a
detail on a project that was closed out and
with a warranty issued. Most substandard
detail and installation issues will not manifest
into an active leakage condition until
the later portion of the service life of a roof
assembly, providing limited risk to the manufacturer
holding the warranty coverage,
but shorting owners of the top-quality, longterm
roof system they paid for and thought
they were obtaining.
While less-than-thorough inspections
and absence of follow-up work or inspections
on most warranted roof systems is an
issue, it pales in comparison to the largest
threat to an optimally installed low-slope
roof assembly: untrained roofing labor.
A major component of this scenario is
the all-too-common and apparently increasing
practice of subcontracting installation
labor to unskilled, untrained, and inexperienced
installers of low-slope systems.
While the overall integrity of the materials
used in low-slope roof systems has routinely
improved, they require a dedicated skill set
to properly install to assure that the assembly
will achieve the optimal ~25-year level of
effective service.
Such untrained labor places a high
degree of pressure on the QA inspector to
monitor the activity and work product of
numerous personnel at once. In some cases,
workers are not cognizant of even why they
are performing a certain work function. Such
a scenario is all too common and results
in the QA inspector either becoming an
instructor or a project manager, neither of
which is his or her responsibility. One way
to curtail this practice is for the roof system
designer to mandate a percentage or number
of roofers on each project who have attended
the training program for the respective roof
system being installed and to verify this
at the onset of construction. Roof system
manufacturers themselves can also mandate
such but are unlikely to do so, as this would
stretch their tech department resources and
actually place them at a slight disadvantage
in competing with other manufacturers
when the roofer is selecting a system for use
on a project.
The importance of QA inspections
extends past the roof system and can have
an effect on future work of RCI professionals.
The following scenario provides an
example.
A building owner decides to replace
the roof due to age and condition and to
halt leakage interruptions that continue to
plague the building’s operation. He does not
hire a roofing professional for the specifications
but simply calls a few local roofers
and obtains pricing. Once he settles on a
roofer, a contract is signed and the roofer
schedules the work. Knowing that this is a
significant expenditure on a roof assembly
with which he has no expertise or experience,
the building owner decides to hire a
roof inspector to ensure he is getting his
money’s worth and a top-quality assembly.
The building owner does a bit of homework
and online searching and ends up at
the RCI website, where he finds a local roof
consultant who offers QA inspections. The
quality of the inspection and the actual
reports that he will receive subsequent to
each inspection are important to the owner.
If the professionalism of either the QA
inspections or the reports is not up to high
standards, chances of that building owner
ever hiring a roofing professional again are
very slim.
Most roofing professionals provide a
high level of proficient service, to which I
can attest as a function of receiving and
reviewing copies of daily QA reports from a
large number of firms on hundreds of projects
all over the U.S. and Canada. But the
news is not all good; there are a few roofing
professionals who pay less attention to their
QA inspections than they should. While the
use of an improperly trained inspector is
not common, the emphasis on providing a
comprehensive written assessment of the
daily work effort in a condensed format
is lacking and the weak link in the QA
inspection chain. Roof inspections should
be performed by persons who are properly
trained and with a working knowledge of the
system being installed, as well as whatever
S e p t e m b e r 2 0 1 5 I n t e r f a c e • 2 5
design enhancements may be applicable for
each particular project. A full copy of the
specifications, roof plan, and details should
be on site and available for the QA inspector
to reference during construction.
The inspector should possess diplomacy
skills, as that is an integral part of the job.
In the event of a dispute, the QA inspector
should provide adequate information to the
parties who will review the data and render
a decision, not attempt to overstep his or
her function as an observer. The QA inspector
should not argue with the roofing personnel
but take up contentious issues with
the designer, system manufacturer, contractor
office, and/or owner. Roof inspectors
should properly represent themselves in a
professional manner and appearance that
serves as a contrast to the roofing workers.
Any contentious detail or application
should be photographed with a smartphone
and forwarded to the appropriate office for a
timely determination that does not slow the
progress of the roofing effort. As for the daily
observation reports themselves, they should
be provided to an owner on at least a weekly
basis for hard copies; and soft copies should
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2 6 • I n t e r f a c e S e p t e m b e r 2 0 1 5
Figure 1 – Sample daily report from a PVC reroof project in New York City. Sufficient daily
information on weather, crew size, and a description of work accompany the images. Lacks
daily and running tally of variable restorative work, but acceptable overall.
be provided as soon as possible—within
three days maximum.
Reports should clearly list all pertinent
roof project data and include a concise review
of the work effort; daily and running tallies of
variable work items such as wet insulation,
replacement, and deck remediation work;
and the number of roofers, visitors, and the
daily progress. A roof plan showing the area
involved on a given day may be included,
providing such information is integrated into
the daily report and is not a separate file. The
same holds for the set of color images taken
each day. Resolution of images should be
adjusted to be sufficiently clear to allow for
close-up expansion on a monitor without a
loss of clarity. High-resolution digital images
also have a penalty, and that is excessive
file size. Some owners (in particular, select
large corporations) have size restrictions
on their e-mail accounts that will preclude
larger-sized files from being accepted. When
combining written report text, color images,
and possibly a roof plan diagram, such
should be converted into a single condensed
Adobe PDF file with a clear number and date
to allow for ease of saving and reference.
Digital images should be at least 2 x 3 inches
in the report, as smaller-sized images are
difficult to review, and the point of a report
to the owner is to make it as easy as possible
for review and reference. An example of
a condensed but effective daily QA report is
shown in Figure 1.
An example of a more complete report
is provided in Figure 2, with a scaled,
color-coded roof plan, written text documenting
the work effort, a running and
complete tally of the variable work items,
and upwards of 12 pages of color images
along with work descriptions. This type of
daily report is optimal, provides the most
complete documentation, and is substantial
enough in size to satisfy even the most discerning
owner. Daily QA inspection reports
that start out with five or six pages of form
fields and checklists can and should be
culled to a one- or two-page document
listing only pertinent data for that project,
followed by the series of color images that
are easier for the owner to read.
Following these recommendations and
guidelines should collectively elevate the QA
inspections and reporting process to a standard
that the industry can remain proud
of while providing the added value to a roof
project in the form of a higher-quality, longterm
low-slope roof installation which, in
the final analysis, is the real objective.
S e p t e m b e r 2 0 1 5 I n t e r f a c e • 2 7
Figure 2 – A more complete report with a scaled, color-coded roof plan, text documentation, and a tally of the variable work items, as well
as color images with work descriptions.
Marc Boulay is
the chief engineer
with Northridge
Consulting Engineers,
Inc., based
in Massachusetts.
He has been
involved with commercial
low-slope
roofing for 34
years. Boulay has
authored numerous
articles and
manuals and has lectured at seminars on
commercial roofing, masonry, and pavement
assemblies. He is an active member of ASCE
and RCI and serves on the Editorial Board
for Interface journal.
Marc Boulay