One of the most
critical issues in the construction of green roofs is their
waterproof integrity. To avoid leakage and drainage backups,
it is important to choose the correct waterproofing membrane
system, root barrier, and drainage system. Specific vulnerable
areas include: roof vent pipes, abutting vertical walls, and
perimeter areas (for leak-detection device information, see
www.roofmeadow.com). Additionally, consultation with a structural
engineer is required for green roofs with a projected live load
of greater than 17 pounds per sq. ft. A heavier load can be
accommodated with internal columns or walls under deeper planting
beds.
Figure 3. Careful installation of green roof to prevent leakage.
