Skip to main content Skip to footer

Avoiding the Landfill: The Recycling of Vinyl Roof Membranes

May 15, 2008

With its European counterparts
blazing the trail,
the North American vinyl
(PVC) roofing industry
has entered a new phase
in its commitment to
environmental sustainability through recycling.
Because thermoplastic single-ply vinyl
membrane can be heated and re-formed
repeatedly over its lifespan, it has long been
an industry best practice to recover production
trimmings and scrap and recycle the
material into new membrane. Well-run and
properly equipped vinyl-membrane production
plants are capable of converting virtually
all of the raw material and components
that go into making the membrane into the
final installed roof system or other applications.
Typical post-industrial recycled products
have included accessories such as
roofing walkway pads, commercial-grade
flooring, and concrete expansion joints. In
addition, scrap can be reintroduced as a
raw material into a subsequent membranemanufacturing
process. Some roofing manufacturers
collect their customers’ scrap as
well as the general-purpose scrap of other
vinyl fabricators for reuse in production of
new membranes.
Building on this track record, the member
manufacturers of the Chemical Fabrics
and Film Association (CFFA) Vinyl Roofing
Division have initiated a feasibility study to
evaluate strategies for making post-consumer
recycling viable on a broad scale, as
has been done in Europe for many years.
Skyrocketing raw material costs, higher
landfill tipping fees, legislation to restrict
disposal of construction material, and an
architectural community that demands the
lightest environmental footprint that can be
achieved are all leading toward the mainstreaming
of post-consumer recycling and a
vision of the day when specifiers call for
post-consumer content in a roof project.
Post-Consumer Vinyl-Roof
Recycling – Where It All Began
Vinyl roofs have been in
use for more than 40 years in
Europe, and roofing manufacturers
there have been recycling
retired roofs into other
useful products since 1994.
That was the year a consortium
of companies funded the
construction and operation of
a facility in Germany to re –
claim the growing volume of
vinyl membranes at the end of
their service lives and return
them to the original manufacturers.
Over the years, the material
taken back has been used
in a variety of applications,
including as feedstock in the
production of new roofing
Contractors easily lift a flexible sheet of retired membrane from the roof to be rolled in preparation for
transport off site. Image courtesy Vinyl Roofing Division, CFFA.
40 • I N T E R FA C E MA R C H 2008
membranes. Typically incorporated into the
back side of the sheet where potential color
variations are not a factor, the recovered
material can comprise 5 to 15 percent by
weight of the finished product. Reports from
the field indicate that, at 10+ years of age,
the first membranes made with recycled
post-consumer material are performing the
same as membranes produced of virgin raw
materials.
Today, ROOFCOLLECT, a program of
the European Single-Ply Waterproofing
Association (ESWA), coordinates the recovery
and processing of post-consumer vinyl
roofing membranes. In conjunction with the
European Commission, ESWA sets annual
targets for post-consumer roof recycling; in
2006, 4.4 million pounds of roofing membrane
were recycled due to its efforts.
ESWA is now working with the recycler
Interseroh to establish a pan-European collection
system that would facilitate recycling
in closer proximity to the job site.
ESWA is also investigating strategies for
incorporating higher percentages of recycled
material into finished membranes.
Less Is More; The Technology Is Here
According to the U.S. Environmental
Protection Agency (EPA), construction and
demolition waste in the U.S. totals an estimated
136 million tons annually.1 The vinyl
roofing industry is committed to combining
existing post-consumer recycling technologies
with logistical expertise to limit its contribution
to these numbers.
Post-consumer recycling of vinyl roof
membranes in the U.S. began in 1999.
Working in tandem with a vinyl membrane
manufacturer, a Massachusetts recycling
company produced a highway cold patching
material made from old vinyl roofing membranes
and other recovered plastics. Today,
state-of-the-art grinding equipment makes
it possible to pro –
cess roofing membrane
and convert it
to feedstock for new
materials.
Only membranes
that have been
m e c h a n i c a l l y
attached or looselaid
have been re –
processed in North
America. There is no
experience, as yet,
with membranes
that have been ad –
hered to insulation
or to other substrates,
but CFFA
members are watching
some approaches
that have been
developed in Eur –
ope.
Pilot Projects Shed
Light on Opportunities
and Challenges
Post-consumer
recycling of roof
membranes has oc –
curred on a limited
basis in the United
States. To date, the
savings in disposal
fees and the value of
the salvaged materials
have generally
ex ceeded the cost
of the additional
la bor, shipping,
and grinding fees.
How ever, the total
net costs are de –
pen dent on total
roofing square
footage, the distance
that the old
roof must be
shipped to be pro –
cessed, and avoided
landfill tipping
fees.
The reroofing
of Boston’s Mar –
riott Long Wharf
Hotel was a pilot
project where the recycling scenario reflected
the ideal logistics: (1) all involved parties
were motivated to recycle as much of the
complete assembly as practical; (2) the pro-
Contractors separate the vinyl membrane from the wall fasteners
and plates, which will also be recycled. Image courtesy Vinyl
Roofing Division, CFFA.
Contractors segregate the fasteners from the seam strips after the main vinyl sheets have been removed from the
substrate. Image courtesy Vinyl Roofing Division, CFFA.
MA R C H 2008 I N T E R FA C E • 41
ject was close to the membrane manufacturer’s
head office; and (3) a local recycler
had an established program for handling
thermal insulation, resulting in minimal
incremental freight charges as a percentage
of overall salvage costs, in addition to the
necessary experience in handling and processing
the old roofing membrane.
Other recycled system components
included the gravel ballast, the metal flashings,
and the extruded polystyrene insulation.
In the end, 95 percent of the existing
materials of the assembly, by weight, were
recycled. The membrane was returned to
the manufacturer for use in other membrane
products. The contractor estimated a
savings of 25 percent versus the traditional
disposal costs, even with the additional
handling required.
A more typical scenario occurred with
the University of Iowa’s Carver-Hawkeye
Arena. This project’s building team was
committed to incorporating a recycling
strategy into its roof replacement project;
however, there was no local insulation recycling
program to help defray the shipping
costs, and the manufacturer was much further
away from the job site.
Nonetheless, university officials found
this approach a cost-effective choice (compared
to tipping fees at a landfill) and more
environmentally friendly. The aged roof was
rolled up, and, to minimize the volume of
material to be shipped back to the membrane
manufacturer and the associated
freight charges, it was first sent to a Cedar
Rapids recycler to reduce the material volume
via grinding.
Later, the membrane manufacturer
processed the material into roofing walkway
membrane, an installation safety product
normally made of virgin post-industrial
Recyclers use specialized grinding equipment to convert retired vinyl membrane to chunks or a powder. Image courtesy Vinyl Roofing
Division, CFFA.
42 • I N T E R FA C E MA R C H 2008
vinyl. Scheduling of this project allowed for
some of the walkway material produced
from the recycled roof membrane to be used
on the new roof.
Recycling Durable Building Products: What Are
the Challenges?
Many end users and plastic recyclers
recognize that the plastics used in durable
goods are often more valuable than those
found in packaging. But mainstreaming
recovery of these plastics is complicated by
a number of unique challenges, among
which are a much wider range of different
and incompatible plastics, a less developed
collection infrastructure, more varied end
products, lower overall volumes of these
materials (particularly on an individualgrade
basis), and a much wider range of
attached foreign materials such as metal,
rubber, foams, fabrics, etc.2
A sustainable recycling strategy re –
quires high-quality reclamation in the teardown,
reprocessing efficiency, and a ready
customer base for the recycled product.
With this in mind, the CFFA feasibility
study on post-consumer vinyl roof recycling
is looking at ways to address the following
issues on a large scale.
Issue: Reclamation
Any long-term approach to reclaiming
old roofs will need to address the training of
roofing contractors in the logistics of tearing
down roof systems for recycling instead of
landfill disposal. Slightly more handling is
involved, as the contractor must separate
the membrane from other waste materials
and prepare it for shipping off the site.
Issues include:
Test your knowledge of building envelope
consulting with the follow ing ques tions devel –
oped by Donald E. Bush Sr., RRC, FRCI, PE,
chairman of RCI’s RRC Examination Develop –
ment Subcommittee.
1. Spray Polyure –
thane Foam (SPF)
comes in two basic
types. What are
they?
2. What is 1/2-lb
SPF?
3. What is the
expansion rate of
1/2-lb SPF?
4. What is the
expansion rate of
2-lb SPF?
5. What are the Rvalues
of 1/2-lb
and 2-lb SPF?
6. What blowing
agents are used
in 1/2-lb and
2-lb SPF,
respectively?
Answers on page 44
Vinyl membranes made of recycled post-consumer materials. Image courtesy Vinyl Roofing
Division, CFFA.
MA R C H 2008 I N T E R FA C E • 43
Preparing and Storing the Membrane for
Transport to the Recycler
Old membranes must be cut into strips
of prescribed widths and lengths and tightly
rolled and tack welded before leaving the
job site for the recycler. As part of the planning
process, roofing contractors will need
to preorder Gaylord boxes and pallets from
the membrane manufacturer based on the
surface area of the roof, the membrane
thickness, and the existing assembly construction.
Scrap membrane and trimmings
from the new installation can be added to
the Gaylord for recycling as well.
Delivering a “Clean” Product to the
Company Providing Size Reduction and
Grinding Services
For best results, the processor needs to
receive a membrane free of foreign materials
like stone ballast and metal fasteners.
Issue: Processing
Many processors can grind reclaimed
materials, but for vinyl roofs to be size
reduced to chunks or a powder, equipment
that can separate such components as felt
backing material and the reinforcing polyester
matrix is needed. Issues include:
Finding a Recycler that Can Process
Reinforced Material
Until recently, felt-backed membranes
could not be reprocessed and had to be
landfilled. Newer equipment can separate
the felt, allowing the sheet to be recycled
with ease. This equipment can also extract
the encapsulated scrim reinforcement from
the polymer matrix. The felt backing and
scrim can be used as fibrous filler when fabricating
concrete blocks for landscaping or
other applications.
Issue: Identifying the Market
The success of roof recycling, as is the
case with all recycling, is dependent on the
will of the participants in the process.
Issues include:
Developing a Customer Base and
Collection Infrastructure
The North American vinyl roofing manufacturers
are committed to developing the
infrastructure to establish a viable program.
With a strong desire for sustainable
construction in the marketplace and efforts
to divert construction waste from landfills,
it appears that the time is right for roof
recycling to grow.
For more than 40 years, durable, highly
engineered, light-colored vinyl roofing membranes
have cooled and protected buildings
in climates around the world. Their long life
cycle – and the associated lower energy consumption
to both produce the raw material
and process it into useful products – is a
significant determinant of their sustainability
as a building product, but it doesn’t stop
there. The vinyl roofing industry is committed
to taking it to the next level and establishing
a North American post-consumer
recycling program.
References
1 “Characterization of Building-
Related Construction and Demo –
lition Debris in the United States,”
U.S. Environmental Protection
Agen cy, Municipal and Industrial
Solid Waste Division, EPA530-R-98-
010, June 1998.
2 Biddle, Dr. Michael B.; Dinger, Peter;
Fisher, Dr. Michael M.; “An Overview
of Recycling Plastics from Durable
Goods: Challenges and Oppor –
tunities,” presentation before Identi –
Plast II, Brussels, Belgium; April
1999.
Carl De Leon is chairman of the technical committee of the
Vinyl Roofing Division (www.vinylroofs.org) of the Chemical
Fabrics and Film Association (CFFA) and the construction
market manager for Canadian General-Tower Ltd., a privatelabel
roof-membrane manufacturer in Cambridge, Ontario,
Canada. He is a member of the ASTM International D-08
Committee on Roofing and Waterproofing, the Special Interest
Group for the Dynamic Evaluation of Roofing Systems
(SIGDERS), and Single Ply Roofing Industry (SPRI). De Leon
has published research on roof membranes and conducts ongoing research with the
National Research Council of Canada (NRC).
Carl De Leon
Answers to questions from page 43:
1. 1/2-lb and 2-lb
2. Generic spray
polyurethane foam
weighing between
0.4 and 0.6 lb/ft3
when fully cured.
3. Approximately 150
times its original
volume to form a
semirigid, nonstructured
plastic.
4. Approximately 35 to
50 times its original
volume and forming
a rigid plastic with
a compressive
strength between 15
and 25 psi.
5. 1/2-lb = R – 3.5 per
inch, and 2-lb =
R – 6 per inch (aged).
6. 1/2-lb typically uses
water, and 2-lb uses
HCFCs and HCFs.
Reference: Spray Polyurethane Foam
Alliance
44 • I N T E R FA C E MA R C H 2008