18 l ROOFINGBC l SPRING 2019 constructed infrastructure reduces the amount of green space available and its rainfall absorbing qualities—replacing them with impervious surfaces like concrete. Concrete takes away from green space acting as a natural sponge. He says, “This is especially true when absorbing areas like wetlands are built over. I’ve seen it happen in other munic- ipalities and parts of the province in my previous life as a claims adjuster. Not only because of the built environment replacing the natural absorbing capacity of the land, but because the runoff has to be re-directed. “So the industry won’t have a problem with mandatory green roofs when they’re properly placed on top of roofs that serve as platforms. Where we may see some issues is ensuring the proper designs and engineering of the green roofs occur and the qualifications of the people doing the installs is up to standard. Because a key aspect of green roofs are the proper design and installation of the waterproofing underlay that supports it. And you have to make sure the growing media is the right type of material so that it doesn’t clog up the filter fabric, the drainage course or the drains themselves.” And that’s where green roofing can get a bad name. It needs to be done by people who understand the systems thoroughly, and it’s understood that the primary reason for any roof is the protection of the building from the elements. Next Steps Unlike many other municipalities, Vancouver has its own building code— directly governed by city council. Carr concludes, “We’ve given city staff the direction to investigate all of the impli- cations of the mandatory green roof policy. They will come back with a report outlining the necessary changes to the building code and the legal changes required for approval. We also asked for other criteria to be included in the report—such as the issues of afford- ability and maintenance costs. Once the report comes back to us we first review it, then approve it, then pass it—and then it becomes a bylaw. It should be ready in the next few months.” COVER www.precisionmetals.ca Your Metal Specialists 8081, 132nd St. Surrey B.C. 604.594.6001 Producing premier Standard and Custom products for the construction industry since 1975 • Tested and certified by • Proudly made in Canada