Selected Answers

From Michael Halliwell of Thurber Engineering Ltd. on May 24, 2016:
Two things jump to mind right away on this questio ...read more Two things jump to mind right away on this question. Load capacity is number one; dirt, water and plants add a fair bit of weight, and you need to be sure the structure will take it (both the roof structure and the building itself). The second that came to mind is drainage. It's great to have the plants, but they can really hinder water flow off the roof and trap water, too. You don't want your current roofing system rotting away prematurely, and excess water ties back into the first though. If you don't have proper drainage, that roof loading will go even higher.