Recycled Materials in
Metal Roofing
By Clinton Hollister
Recycling, green buildings, sustainable design,
LEED
credits, ozone layer depletion, global warming, depletion of energy
resources, environmental protection ... These are not just the trendy
buzz
words, but absolutely relevant to the fundamental quality of our lives
and
the lives of our children and grandchildren. The need to conserve our
resources is not an option but a necessity.
Metal has been used in roofing for centuries due to its strength and
durability. And as public demand for environmentally friendly,
sustainable
resources grows, metal’s “recycle-ability” makes it an increasingly
attractive material. While other roofing materials that use oil
derivatives
typically end up
in a landfill, the metal industry has been recycling material for
centuries with ever-increasing efficiency.
According to the Steel Recycling
Institute, 50 percent of the steel produced in the past 50 years has
been
recycled. Recycling of metal not only lowers the cost of the product,
but
more importantly conserves our earths finite resources and reduces
environmental damage
caused by solid, liquid and gaseous wastes.
Recycling Trends
Steel
Steel,
the world’s most recycled material according to the Steel Recycling
Institute, was recycled at a rate of approximately 76% in 2005. The
steel industry divides recycled steel into two components:
- Pre-consumer (or
post-industrial) steel
Manufacturing scrap or steel that did not result is a used product
- Post
consumer steel
Steel than has been produced into a product sold to a consumer and is
now being
recycled
Steel is primarily produced using the Basic Oxygen
Furnace (BOF) process or
the Electric Arc Furnace (EAF) process. According the Steel Recycling
Institute and the American Institute of Steel Construction, Inc., the
BOF
product uses on average 23% post-consumer steel and 7% pre-consumer.
The EAF
process yields approximately 59% post-consumer steel and
33 % pre-consumer scrap.
The percentage of recycled material used varies according to the
source, and figures from individual mills are often unavailable.
Conservatively, The Metal Initiative
reports use of 25% recycled steel, which was reaffirmed in the February
2006
issue of metalmag. Some individual mills
report a higher percentage of recycled steel.
The Metal Construction Association (MCA) reports that new steel made
with
recycled material uses as little as 26% of the amount of energy that
would
be required to make steel from iron ore.
Aluminum
Aluminum, which has the reputation for greater longevity is a close
competitor to steel (based on the total square footage produced of
IMETCO’s standing seam product). The
Aluminum Association web site lists the recycled content of the
material at
80 - 85 %, approximately one-half of which is from post-consumer
sources. Production
from scrap uses only 5% of the energy required for production from
bauxite
ore.
Copper
According to MCA, copper recycling is at about 45 %. However, these
figures are a bit skewed with respect to metal roofing since copper
wire,
the largest consumer of copper, must be pure. Copper roofing is
estimated to
contain approximately 75% scrap, 50% of which is post-consumer.
LEED-ing the Way
Much credit should be given to the US Green Building Council’s
Leadership in
Energy and Environmental Design (LEED®)
Green Building Rating System. This
rating system, which is being adopted by several federal agencies and
states, provides "points" for recycled content. The system makes
buildings more attractive to owners
with cost savings through better energy efficiency and potential tax
reductions.
Currently, up to two LEED points
are awarded when 10% recycled material is used throughout the building
envelope, and an increase to 20% is forthcoming.
Metal roofing contributes substantially toward
LEED
points and the environmental goal of sustainablility, a concept whereby
society meets its present needs while preserving the ability to meet
future
needs. Materials used in metal roofing differ in the average of
recycled
content according to the base metal.
For LEED purposes, the percent of recycled material is calculated by
adding
the percent of post-consumer content plus ½ of the pre-consumer
(post-industrial) content.
The LEED rating system presently does not take into consideration that
the
metal used for a building project has the potential to be almost 100%
recyclable when that time arrives.
Read more about the USGB and its LEED system by clicking here to
download
Building
Momentum: National Trends and Prospects for High-Performance Green
Buildings, a report prepared for the U.S. Senate Committee on
Environment
and Public works.
Beyond the Mill
We as individuals can play a part. Here are some suggestions:
-
Urge your communities
to support recycling by offering curb-side recycling services.
-
If collection services are not available in you area yet, find out
where your
local recycling center is
and contribute your recyclables when you "can."
- Organize a simple recycling program at work by
placing bins for
recyclables next to the trash cans and, if no collection service
available,
ask for volunteers to sign up for drop the bins off at a nearby
collection
center.
- For larger offices,
your waste management company may offer a recycling program - find out
how
to take advantage of the services available to you.
As a sales professional, I am certainly not an
expert on the subject of metal recycling. But with an ardent desire to
help
preserve our limited and precious resources, I have compiled this
article
from several available sources. If you have any comments, suggestions,
or corrections,
you contributions are most welcome.
