Design Aspects of the Arboretum Green Roof

Green Roof Symposium

Project Issues:

• Shady location• Close to natural grade• Teaching tool for arboretum

University Issues:

• Risk Management - 70% lawsuit/roof failures ratio• Maintenance• Warranties• BCOM Approval

A Short History of Roofs…

there are several types of roofs:

roofs that shed water:

▪ metal roofs▪ shingle roofs

A Short History of Roofs…

roofs that are barriers:

▪ EPDM▪ TPO▪ Modified Bitumen▪ PVC

▪ single-ply roofs (sheets) -

▪ liquid-applied membranes

there are several types of roofs:

A Short History of Roofs…

typical single-ply installations:

there are several types of roofs:

A Short History of Roofs…

IRMA roofs:

there are several types of roofs:

A Short History of Roofs…

green roofs:

there are several types of roofs:

▪ extensive/intensive▪ planted in place

▪ green grid

green roofs:

the JMU Arboretum will be extensive

green roofs:

▪ extensive/intensive

advantages:▪ wrap around warranty ▪ membrane by a reputable local installer

disadvantages:▪ more costly to repair leaks▪ single supplier requires exemption from BCOM▪ immature plants may be installed in summer, requiring watering

green roofs:

▪ planted in place

green roofs:

▪ green grid

advantages:▪ grids are removable for repair▪ can be installed on any roof membrane▪ plants can be installed later, once established & more mature

disadvantages:▪ no wrap around warranty with preferred roofing manufacturer▪ possible additional cost▪ single-source exemption from BCOM▪ available details▪ warranty

critical steps:

▪ provide information on each system▪ technical information▪ research references for each system▪ find installations for client to view▪ create comfort with decision

architect as advisor:

JMU arboretum