Assemblies

Type III - 6.00 - 14.00 inches of media
Type IV - 12.00-14.00 inches of media

The green roof is an at-grade assembly over underground office space and is characterized by low-growing flowering groundcovers (primarily Sedum-varieties) and accent plants including Allium, Chrysanthemum, Carex and Chamomile. To accommodate the client’s aesthetic and budget objectives, the Boeing green roof was designed and built to offer the appearance and advantages of a traditional plaza landscape, while keeping the thickness and weight of the cover system to a minimum. The roof is adjacent to a parking lot and accessible to Boeing employees. Most of the green cover system is 6.00 inches deep, consisting of un-irrigated plantings bisected by a serpentine walkway created from cast-in-place concrete. Patios, created using both unit pavers and cast-in place heat-traced concrete pavement, provide a place for Boeing employees to sit outside.

Only 10% of the total area of the Boeing green roof is intensive (over 6.00 inches deep). The intensive areas average 12.00 – 14.00 inches in depth and are irrigated using the base flood method. The intensive irrigated areas support large perennials and bushes and are strategically distributed providing the appearance of a lush landscape. A glass cupola acts as a skylight allowing light into the below grade rooms underneath the green roof. Conversely, the cupola provides light for the green roof at night.

The green roof areas respond like open space for rainfall events up to 25-year return storms.