GREEN ROOFS: All You Need To Know
- By Stephen and Rebekah Hren, The Carbon-Free Home
For the owner of an existing home, the ability to create a green roof may be limited, due to concerns about weight, although not as much as might be initially supposed. Lightweight green roofs are possible on existing roofs with a pitch of up to 30 degrees. If the homeowner has access to the framing members of the roof via an attic, then reinforcement of load-bearing members is possible, and a heavier, more diverse green roof can be achieved. As a retrofit, the effect of going from a dead zone of tar or asphalt shingles to a thriving garden of flowers and birds can be very dramatic and is a joy to witness.
Green roofs are differentiated by the depth of the growing medium, as this directly relates to weight—the primary structural concern.