20.0
psf
20.0
psf
40.0
psf
40,000
lbs
Green roof systems impose significant additional loads on structures compared to conventional roofing. Extensive systems (2-6" growing medium) typically add 15-25 psf, while intensive systems (6-24"+ growing medium) can add 35-150+ psf. These calculations include saturated soil conditions, vegetation, and structural safety factors.
Growing medium (saturated), drainage system, root barrier, waterproofing, insulation, and structural deck. Saturated soil weight is typically 100-120 pcf.
Occupancy loads, maintenance equipment, snow loads, and temporary construction loads. Minimum 20 psf for accessible areas.
Wind uplift, seismic forces, and thermal expansion. Green roofs can reduce wind uplift but increase seismic mass.