Page 21 - Green Builder Magazine Nov-Dec 2017 Issue

Clearing the Air

Selling the concept of a green roof sometimes requires shattering a few myths.

BY GREEN BUILDER STAFF key problem could lie with the age of the roof when the garden goes in.
Building codes for a new home take into account the impact of a green
USTAINABILITY HAS BEEN a strong selling point for roof upon the structure’s designed load. But retrofitted green roofs are
residential homes for about a decade. Between increased subject to varying requirements based on geography and the home’s
and improved enviro-friendly building standards and original load capability.
a general desire by homebuyers to “do right” by the 4. Only succulents can be used on a green roof. Water-storing
environment, it’s good to go green—and even better to plants are popular because they look good and can withstand fairly
Squietly brag about it. harsh conditions while up on the roof. But many types of vegetation can
But while consumer literature, building competitions and on-site home survive, particularly native grasses, if the right conditions exist. Irrigation is
tours gleefully point out obvious green components—such as low-flow the key, as all plants need water (to some degree).
showerheads, LED lights, Energy Star-rated appliances—and the less 5. A green roof is just some dirt on the top of the house. Strange
obvious, such as triple-pane glass, ultra-efficient insulation and recirculating how illogical this sounds, but for some builders and buyers, it makes perfect
heat pumps—there’s an item that presents itself nicely to the crowd and is sense. A regular, ground-based garden is more than a couple shovels of
more likely to get visitors to at least snap a photo of the house, if not flat-out dirt. There are times when a green roof doesn’t even need soil. It’s not as
beg for a key to the front door.
You might say that item—the green, vegetated
or “living” roof—is a bit over the buyer’s head…
and that’s a good thing.
To help remove, or at least clarify, some of
the buyers’ and builders’ preconceived notions
about green roofs, here’s a look at a few
common myths and how to work around them
with customers.
1. All green roofs are the same, no mat-
ter what they’re called. There’s some truth
here: By definition, a green roof is one that pro-
motes plant growth as a tool for climate control
and better air quality. But aside from that, there
are three types of living roofs: “intensive” green
roofs or roof gardens, which are accessible and
may include larger plants and water features;
“extensive” roofs, which are thinner, lighter and
closer in appearance to a standard roof; and
“semi-intensive,” which contain numerous dif-
ferent plant species, mostly native grasses and
flowers. CREDIT: PHOTOTOURING/FLICKR
2. Green roofs are a new environmen-
tal trend. Contrary to this belief, green roofs
have existed in some form since the era of
Ancient Greece. The modern vision of living roof Time tested. Contrary to popular belief, green roofs and their air-cleansing capabilities
have literally been on the scene for centuries.
appeared in mid-1940s Europe. Like so many
items in the early baby boomer years, homes with green roofs became simple as mere potting soil—perlite or other porous materials are typical
popular, but were in short supply. components. But it’s not an impossible task, either.
3. Green roofs cause structural problems. If a roof is going to 6. Once a green roof is installed, the owner is on their own.
leak, it’s going to leak no matter if there is grass or tile shingles up there. Because they use various under-warranty building products, the same
A properly designed living roof—one with a solid waterproofing member protections apply to green roofs as for any covered component inside the
(something all roofs are supposed to have)—will be just as reliable as home. Every roof handled by a professional installer, green or otherwise,
a regular roof. It may even better protect the structure, because the should have a service contract available for annual maintenance. How much
plants act as an extra barrier to wood-destroying ultraviolet light. The it covers depend on exactly what the owner has planned for the roof. GB

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