The folks at Roofscapes, Inc. have logged many hours on green roofs
over the years – both in Germany and in the United States, and
we have researched all types of green roof materials. We have seen – both
in the lab and in the field – what works and what doesn’t.
So, we thought we’d reserve this corner of our website to debunk
what we consider to be myths in the marketplace. At the very least,
we hope that these observations give you some food for thought.
MYTH 1: Irrigation is essential
for green roof success Well, no and yes. The
requirement for irrigation will depend on the climate and the type
of vegetation that must be supported. Read more...
MYTH 2: The most common reason
for green roof failures is inadequate moisture Without doubt, when green roofs fail to thrive, the
most common culprit is too much moisture. Read more...
MYTH 3: Fabrics can make good
moisture storage layers Fabrics offer an effective
method for intercepting and distributing water, but distributing water
and storing water are two very different things. By their very
nature, fabrics can never be very effective as water storage components. Read more...
MYTH 4: Modules are the lowest
cost, ‘tried and true’ method for green roof installations Always
keeping an eye on the young and dynamic U.S. green roof market, we’ve asked ourselves lately, “What’s
with the modular-green-roof craze?” How do modules compare to
the traditional German-style green roofs planted ‘in situ?’ (In
situ installation involves assembling the green roof, layer-by layer,
directly on the roof.) Read more...
MYTH 5: All green roofs are
effective replacements for open space All green roofs can replicate open space (meadow) conditions
for some storm events. Shallow green roofs will be effective
in controlling small rainfall events, while deep assemblies may be
required to control large storms. Read more...
MYTH 6: Green roofs are good
insulators By and large, green roofs are poor
insulators. Most
of the time, green roofs are heat capacitors; that is, they can absorb
and release energy. The effectiveness of green roofs in managing
energy is related primarily to two phenomena: 1) heat capacitance,
and 2) latent heat of evaporation and freezing. Read more...
