Increasing Sustainability in the Low-Slope Roof Market through PVC (Vinyl) Membrane Recycling

30 • IIBEC Interface November 2023
Increasing Sustainability
in the Low-Slope Roof
Market through PVC (Vinyl)
Membrane Recycling
Feature
By Jennifer Oblock, Jay Thomas,
Richard Krock, Buddhika Hapuwatte,
and Nehika Mathur
This paper was originally presented at the 2023
IIBEC International Convention and Trade Show.
more than a million pounds is being converted
into new membrane annually as production lines
are designed to blend granulated recycled PVC
material with virgin feedstock.
Total net costs of postconsumer recycling
depend on total roofing square footage, the
distance the old roof must be shipped to be
processed, and avoided landfill tipping fees. In
some cases, the savings in disposal costs, the
value of the full range of salvaged materials,
and potential building appraisal appreciation
for green building credits can offset the cost of
the additional labor, shipping, and grinding fees
involved to remove and reuse end-of-life (EoL)
PVC roofing material. As a result, more active
consideration is being given to making the
commitment to incorporate a recycling strategy
into a roof replacement project.
LANDFILL AVOIDANCE
While landfills can offer a convenient and in some
cases a less costly disposal option for roof tearoffs,
landfills in certain geographical regions that
are reaching capacity limits may need to begin to
be utilized for the more distressed materials that
do not have any alternative (EoL) dispositions. This
creates an opportunity to avoid the landfilling of
materials with recycling options available, such as
PVC single-ply membranes. Landfill avoidance for
PVC single-ply roof membranes not only avoids
disposal costs but can also drive several other
positive-value generators for an enterprise or
building owner.
PVC roof membranes at their EoL can be
recovered for subsequent processing at a PVC
recycler. PVC recycling capacity exists for a
portion of the PVC membranes torn off, and
if presented with continuing opportunities to
process more tear-off material, PVC recyclers
can plan capacity and technology additions
to accommodate the additional material
opportunity. This creates jobs and economic value
in the recycling industry while preserving the PVC
molecule initially created in the resin production
process. The overall environmental benefits and
resource conservation accrued by recovering
PVC materials are significant in the form of
reduced greenhouse gas and other impacts and
can be quantified using environmental product
declarations (EPDs) based on the results of
detailed life-cycle assessment (LCA) methods.1
CARBON AVOIDANCE
QUANTIFICATION
The increased global concern about greenhouse
gas emissions (henceforth called “carbon”)
and the industrywide efforts to curtail those
emissions have led businesses to set carbonreduction
and “net-zero” goals. With many
companies paying for carbon credits to meet
their goals, carbon avoidance is leading to direct,
and increasing, monetary value for businesses.
Many commercial building owners and real
estate companies have committed to reducing
their carbon footprint and actively search for
ways to reach reduction targets. Although carbon
credits are a regulated market and typically
not applicable to recycling in North America,
quantifying carbon avoidance in roof recycling
will benefit stakeholders when calculating their
voluntary carbon reductions. Furthermore, such
quantification will bring a new value proposition
for roof recycling and incentivize building owners
who drive the demand for it.
Interface articles may cite trade, brand,
or product names to specify or describe
adequately materials, experimental
procedures, and/or equipment. In no
case does such identification imply
recommendation or endorsement by the
International Institute of Building Enclosure
Consultants (IIBEC).
TRIPLE BOTTOM LINE (TBL) accounting
(people, planet, profit) was introduced in the
mid-1990s. Since then, enterprises of all sizes
across all industries have begun to analyze
their company value not just from a financial
position, but also from an environmental and
social responsibility perspective. Resource
conservation fits well with a TBL approach
in the form of material recovery, including
slowly decaying waste plastic such as polyvinyl
chloride (PVC). Optimal value for PVC roof
replacement can be enhanced by recycling
“tear-off” waste, or old PVC membrane, at
the end of its useful life. This article reviews
potential environmental, social, and corporate
governance (ESG) benefits of roof recycling;
reviews the roof recycling process and options;
and identifies steps for the roofing industry to
scale up the practice.
In North America, postconsumer recycling
of PVC roof membranes began in 1999.
Working with a PVC membrane manufacturer,
a Massachusetts recycling company produced
a highway cold-patching material made from
ground-up old PVC roofing membranes and
other recovered plastics. As state-of-the-art
recycling equipment evolved to size reduce and
separate polyester scrim reinforcement and felt
backing from the PVC polymer, retired roofing
membrane became feedstock for new products,
such as roofing walkway pads, commercialgrade
flooring, and concrete expansion joints.
While the production of walkway pads might
consume a few hundred thousand pounds of
product a year for any one manufacturer, now
November 2023 IIBEC Interface • 31
Due to the importance of carbon avoidance in
the industry, the National Institute of Standards
and Technology (NIST) is working on methods
to measure the carbon avoidance generated by
recycling materials at the end of their service life.
For specific industrial applications, such as roof
recycling, consensus will be needed around key
aspects of the measurement approach to create
standards. Standards will support fair practices
that can strengthen markets for these types of
recycled materials.
The basic idea of carbon avoidance
quantification is an estimation of the difference
in carbon emissions between a typical
practice, such as disposing of the EoL roof in a
landfill, and an alternative approach, such as
recycling. To use this information in a market
setting, consideration needs to be given to the
allocation of these savings across the value chain
participants—building owners, converters,
and PVC product manufacturers. The carbon
avoided in different processing steps will need
to be allocated among them equitably to avoid
any double counting, while at the same time
encouraging the formation of a market for the
materials by crediting the roles of the different
value chain participants. LCA literature provides
different allocation methods that can be used.2
A standard for accounting for these savings will
need to guide the choice of the one appropriate
to the situation.
ESG COMMITMENTS
Green building rating certifications can be one
aspect of an enterprise sustainability platform.
Enterprises that are pursuing ESG framework
reporting could include green building ratings as
part of their sustainability-related opportunities.
Roof recycling can be a tangible and measurable
aspect of ESG metrics.
Table 1. Credits available for existing buildings from voluntary consensus type green building rating systems for diverting roof tear-off from landfills
Voluntary Rating System Applicable Section Credit Language
Green Building Initiative3
(2021)
5.1.1.5 Waste Management for
Cycle Renovations
Requires waste management
policy, procedure, and plan for
cycle renovations
U.S. Green Building Council4
(2021)
MR Prerequisite—Facility
Maintenance and Renovations—
Waste Management Policy for
Maintenance and Renovations
Establishes goals and strategies
for renovation waste diversion
BREEAM5 (2015) 11.0—Wst 01—Project Waste
Management
Requires options and actions
to reuse or recycle materials,
reducing and diverting waste
from landfill
Figure 1. Recycled value stream and the role of each member of the process.
For buildings pursuing green rating
certifications, credits are available from voluntary
green building rating systems (Table 1) for
diverting construction wastes from landfills.3—5
Recycling back to a PVC membrane manufacturer
can also help that manufacturer reach some of
its sustainability targets, as prescribed in ANSI/
NSF 347, Sustainability Assessment for Single Ply
Roofing Membranes.6
The benefits of recycling PVC single-ply roof
membranes are numerous. How much value
is realized for the building owner, whether
32 • IIBEC Interface November 2023
through higher asset value or higher occupancy
rates or revenues, can depend on many factors.
The Institute for Market Transformation and the
Appraisal Institute concluded that “green building
property performance and value can show up
across the board in quantifiable property metrics
and favorable adjustments made during appraisal
and underwriting.”7
THE ROOF
RECYCLING PROCESS
A successful long-term roof recycling program
requires an engaged roofing value chain (Fig. 1)
with motivation to undertake the effort to recycle
rather than dispose of EoL roofing membrane.
Building owner/developer demand for recycling
is fundamental to program success. The reroofing
project is more likely to be pursued if the
owner is aware of the option and has asked for
it to be included in the reroofing project. Draft
specification language should be added to the
specification to ensure roofing contractors are
aware of the request in the bidding process.
The roofing manufacturer, possibly with the
assistance of an industry association, can fulfill
the role of value chain educator. Working through
marketing communication and sales force
outreach, success in communicating the positive
benefits of recycling is important to recycling
success. Education throughout the value chain will
create positive word of mouth and reduce barriers
Figure 2. Roofing contractor removing PVC roof membrane and prepping for recycling.
Source: Benchmark, Inc.
Figure 3. Closed-loop recycling. The PVC membrane manufacturer manages the process and
recycles the material into new PVC membranes.
Bldg.
Owner
Mfr. Recycler
34 • IIBEC Interface November 2023
Figure 5. Open-loop recycling. The PVC membrane manufacturer specifies recycling with the owner. The recycler then sells to the open market.
to changes in behavior. The roofing specifier,
contractor, and distributor all play important
roles in the education process.
The first step in the process of roof recycling
is matching supply and demand to ensure a
viable market for any collected material. The
next steps are securing the infrastructure
necessary to carry out the reverse logistics of
moving the material from the job site to the
recycler and identifying a recycling network
capable of and interested in processing the
materials.
A PVC roof recycling project candidate
can be a roof of any age or size, but certain
parameters increase the attractiveness of the
material for recycling. Generally, roofs larger
than 800 squares (80,000 ft2 [7,400 m2]), are
excellent candidates for recycling since the
quantity allows for a full truckload of material,
and roofs less than 20 years old have the
benefit of modernized PVC formulations which
1116228_Editorial.indd 1 10/11/2023 1:37:26 AM
Figure 4. The Rogers Centre in Toronto, Canada.
Source: Sika Sarnafil.
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PROFESSIONAL DEVELOPMENT
IS ONGOING THROUGHOUT AN
INDIVIDUAL’S CAREER.
IIBEC
MENTORING WITHIN
THE PROFESSION
information:
36 • IIBEC Interface November 2023
may be more desirable for the next use of the
material.
Since the average-size low-slope commercial
roof is 250 squares (25,000 ft2 [2,300 m2]), a
consolidation network may be needed to bring
together enough material to avoid less-thantruckload
shipping costs. Collecting a roof
sample for lab analysis of physical properties will
provide an indication of the viability of recycling
and appropriate end dispositions. Some
additives used 20 years ago are no longer used
in today’s modernized PVC roof formulations.
Mechanically attached roofs are preferred;
adhered roofs are problematic because of the
facer material that is typically delaminated from
the roof insulation or coverboard during the
tear-off process, and this becomes challenging
contamination to remove during the recycling
process.
The roof removal process for recycling is
very similar to removing the roof for disposal.
Removing debris from the roof with a leaf blower
is a good first step to minimize foreign material.
Typically, the pallets used for new material
delivery are repurposed to hold the material
removed from the roof. Instead of the membrane
being tossed down a trash chute, it is rolled,
ribbon folded, or cut into 10-ft (3-m) strips for
loading on a pallet. The membrane is cut along
the seams to ease removal and eliminate metal
plates and fasteners (Fig. 2). These metallic parts
can also be collected and recycled. Under ideal
conditions, each pallet can hold 3,500 ft2 (330
m2) of membrane. Metal or braided strapping is
used to secure the membrane to the pallet.
RECYCLING OPTIONS
The PVC recycling industry in the US and Canada
is robust, with over 100 recyclers handling
mostly PVC preconsumer scrap; the volume of
EoL PVC material has grown to about 13% of the
total PVC recycled.8 Surveys conducted by Tarnell
Figure 6. Overhead view of the PVC membrane reroof project at Bishop Elementary School in Ypsilanti, Michigan.
Note: PVC = polyvinyl chloride.
Source: Duro-Last Inc.
Recyclers processed
1.1 billion lb
(5 × 108 kg)
of vinyl comprising
950 million lb
(4.3 × 108 kg) of
preconsumer scrap
and 140 million lb
(6.4 × 107 kg)
of postconsumer
material in 2019.
November 2023 IIBEC Interface • 37
Figure 7. PVC roofing membrane from roof
tear-off transported from job site to recycling
facility.
Photo courtesy of Duro-Last Inc.
Company and sponsored by the Vinyl Institute
estimate these recyclers processed 1.1 billion
lb (5 × 108 kg) of vinyl comprising 950 million
lb (4.3 × 108 kg) of preconsumer scrap and
140 million lb (6.4 × 107 kg) of postconsumer
material in 2019.9
The Chemical Fabrics and Film Association
(CFFA) completed a survey of its Vinyl Roofing
Division (VRD) members in 2022 and estimated
that 19.1 million lb (8.7 Thousand Metric Tons)
of preconsumer and over 1.0 million lb (0.5
Thousand Metric Tons) of postconsumer singleply
PVC roof membranes was recovered and
recycled that year.10 The CFFA VRD also estimates
that of the installed PVC roof membrane
reaching its EoL this year, approximately 19
million lb (8.6 Thousand Metric Tons) may be
available for recovery.
PVC recyclers are selective about what types
of material they process and will specialize in
either rigid or flexible PVC. Because PVC singleply
roofing contains plasticizers, it is categorized
as flexible material and must be directed to a
facility that processes this type of PVC. Several
PVC product manufacturers also take their
products back at their EoL and recycle the
reclaimed materials back into new products.
The typical mechanical recycling process for
EoL single-ply PVC roof membrane involves size
reducing the tear-off rolls using shredders and
then granulating the material. While low-speed
shredders can accommodate a small amount of
foreign material, higher-speed granulators have
sharp blades and screens that must be protected
from any foreign debris, such as wood, stones,
and metal. Shaker tables and magnets can be
employed to assist in separating this debris,
but complete removal of highly contaminated
materials is often infeasible. It is best to keep
incoming material free of wood, stones, and
metal. Once the membrane is granulated,
aspirating the material to remove the fiber
reinforcement is an option depending on the
end-use disposition.
For closed-loop recycling (Fig. 3), where
the material will be reprocessed back into
single-ply roof membranes, the fiber must be
removed. Further size reduction, including
smaller granulation or pulverization, enables
a more complete aspiration of fiber out of the
material. Once the fiber is removed, this granular/
pulverized material becomes feedstock for
recompounding with specifically modified virgin
blends of compounds that will meet the desired
performance specification for that layer of the
membrane roof.
The Rogers Centre (Fig. 4) in Toronto, Canada,
case study provides more context on the closedloop
process.11
For open-loop recycling (Fig. 5), where
the material is used in a non-roof-membrane
application, leaving the reinforcing fiber in the
granulated material depends on the application.
Significant amounts of pre- and postconsumer
PVC roof membranes are recycled into flooring
applications, where the fiber helps reinforce the
flooring composition. Flooring applications using
PVC roof membrane include calendared sheet
flooring and molded interlocking tiles. In addition
to flooring, use in concrete expansion joints
and roof walkway pads presents a significant
opportunity to consume large amounts of
recycled PVC membranes. Other open-loop
applications where more cosmetic surfaces are
preferred, such as automotive floor mats, or
where smooth surfaces are desired, such as hoses,
may require substantial removal of the fiber.
The PVC membrane reroof project at Bishop
Elementary School (Figs. 6 and 7) in Ypsilanti,
Michigan, provides more context on the openloop
process.12
Advanced recycling alternatives to mechanical
recycling are also being developed. Selective
dissolution of the PVC molecule using specific
solvents is progressing, since it can recover
the PVC or compound ingredients with high
purity without including any of the reinforcing
fiber. Technology for selective dissolution and
processes to handle composite PVC material,
including roof membranes and fabric, are being
developed by Polyloop in France13 and the
Fraunhofer Institute in Germany. The German
process called Creasolv14 can yield high-purity
PVC for circular use. (Any mention of commercial
products is for information only; it does not
imply recommendation or endorsement by
NIST, CFFA, or VI.) Fraunhofer is developing
additional processes to further hydrogenate
certain phthalate plasticizers to other ester
forms for circular use. A pilot plant in Germany is
nearing completion to demonstrate feasibility for
recovered EoL PVC flooring and is being partially
funded using EU grants.
INDUSTRY COLLABORATION
Postconsumer roof recycling has been practiced
in the US for more than 20 years, but it still
only touches a small fraction of the available
roofing materials. Experience has shown
that, to grow volumes significantly, broad
industry collaboration will be required. Several
procompetitive activities could be organized
under an industry collaborative that would
enhance the recycling process and encourage
growth. Some examples include the following:
• Developing a network of regional material
consolidators
• Establishing a joint education program to
grow awareness of recycling as an option
• Developing recycled PVC material
specifications to facilitate end-use markets
A sustainable recycling strategy requires
high-quality reclamation in the tear-down,
reprocessing efficiency, and a ready customer
base for the recycled product. Keeping the
firm commitment to evolving postconsumer
recycling initiatives is key in limiting the
environmental burden posed by construction
materials. By collaborating, the industry can
efficiently and effectively address the hurdles
to expanding the volume of material recycled.
Since recycling a roof must be decided
before the project begins, the first step is
to incorporate a recycling plan into the bid
package on your next roof replacement project.
One way to ensure this step is to complete
a design review summary that includes a
sustainability section discussing the EoL
disposition of the torn-off roof.
REFERENCES
1. Chemical Fabrics and Film Association (CFFA). 2021.
An Environmental Product Declaration. https://
vinylroofs.org/wp-content/uploads/2021/06/CFFAEPD_
FINALw_logos_1406202173.pdf.
2. Schrijvers, D. L., P. Loubet, and G. Sonnemann.
2016. “Developing a Systematic Framework for
Consistent Allocation in LCA.” International Journal
of Life Cycle Assessment. 21 (7): 976–993, https://
doi.org/10.1007/s11367-016-1063-3.
3. Green Building Initiative (GBI). 2021. Green Globes
Building Certification, Existing Buildings. Technical
Reference Manual, p. 212.
4. U.S. Green Building Council (USGBC). 2021.
Leadership in Energy and Environmental Design
(LEED) Reference Manual. v4.1 Operations and
Maintenance, MR Prerequisite: Facility Maintenance
and Renovation Policy: 52.
5. BREEAM—Building Research Establishment
Environmental Assessment Method. 2015.
International Non-domestic Refurbishment, Nondomestic
Buildings, Technical Manual. SD224 1.4:
260–263.
38 • IIBEC Interface November 2023
6. NSF International. 2018. Sustainability Assessment
for Single Ply Roofing Membranes. NSF/ANSI 347.
Ann Arbor, MI: NSF International.
7. Institute for Market Transformation and the
Appraisal Institute. 2013. Green Building and
Property Value: A Primer for Building Owners and
Developers.
8. Krock, R., and S. Tarnell. 2015. “Recycling as a
Sustainable Practice in the North American Vinyl
Industry.” SPE ANTEC Proceedings, Orlando,
Florida, March 25, 2015: 2524–2530. https://www.
vinylinfo.org/wp-content/uploads/2019/01/Krock-
Vinyl-Institute-Recycled-Vinyl-as-a-Sustainability-
Practice.pdf.
9. Vinyl Sustainability Council Vinyl Recycling Summit.
2021. https://vantagevinyl.com/2021-vinyl-recycling-
summit.
10. CFFA. 2022. Avoiding the Landfill: The Recycling of
PVC Roof Membranes. https://vinylroofs.org/wpcontent/
uploads/2022/03/RecyclingWhitePapermarch22.
pdf.
11. Sika Corp. n.d. “Sarnafil Roof Hits It out of the Park
in Toronto—Twice!” https://usa.sika.com/sarnafil/en/
sika-at-work/arenas-recreational-facilities/rogerscentre.
html.
12. Vinyl Sustainability Council. n.d. “Elementary
School Roof Scores an A+ for Sustainability.”
https://vantagevinyl.com/elementary-school-roofscores-
an-a-for-sustainability.
13. Polyloop website. n.d. https://polyloop.fr/?lang=en.
14. Circular Flooring. 2020. “Construction of the
CreaSolv® PVC Prototype Recycling Plant Has
Started,” November 12, 2020. https://www.circularflooring.
eu/news/construction-of-the-creasolvr-pvcprototype-
plant-started.
ABOUT THE AUTHORS
JENNIFER OBLOCK
Jennifer Oblock is an
account executive at
Thomas Associates, a
trade association
management company
headquartered in
Cleveland, Ohio. Since
2013, she has been
immersed in
association duties,
working closely with
associations of all sizes.
Oblock represents the Chemical Fabrics and Film
Association, where she serves as its executive
director. Her experience covers the full range of
association activities, including all aspects of
project and meeting management and serving
as the principal liaison to association directors
and officers. She holds a bachelor of arts degree
in business with a concentration in marketing
from Mercyhurst University.
Jay Thomas is vice president of sustainability
for the Vinyl Institute and executive director for
the Vinyl Sustainability Council.
Richard Krock is principal of VyChlor
Advisors LLC.
Buddhika Hapuwatte is a PREP Fellow at
National Institute of Standards and Technology
and a Post-doctoral Associate at University of
Maryland.
Nehika Mathur is an industrial engineer at the
National Institute of Standards and Technology.
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LinkedIn is changing. The social media platform, long used for professional networking
and job hunting, has seen a growing number of posts that dwell on personal news—
engagement announcements, fertility journeys, cancer diagnoses, and relationship statuses
included.
“After the pandemic blurred the lines between work and home, many employees
reprioritized their lives, giving more emphasis to well-being and family,” wrote Danielle Abril
in the Washington Post. “As a result, workers have become comfortable getting personal on
LinkedIn.”
Users who have opened up about their personal lives on the platform have no regrets.
“They are able to reveal their authentic selves, relate to others, and often receive meaningful
responses from their followers,” Abril wrote.
But because not everyone likes the influx of personal posts, LinkedIn has changed its
algorithm to highlight “more posts from people’s direct connections and followers as well as
those from people outside their networks that are grounded in professional knowledge and
advice,” Abril noted.
Critics of the intrusion of personal news into LinkedIn posts fear that the site’s defining
quality is being eroded. Americus Reed, marketing professor at the Wharton School of
the University of Pennsylvania, told Abril that many people are complaining about posts
focusing on personal matters. According to Reed, “People have a lower tolerance for this
type of stuff because LinkedIn is so well situated in its professional identity.”
Should
LinkedIn
Ditch
Personal
Posts?
Special interest