b'FIRE SAFETYInanattempttodesignsafegreen roofs, a significant experimental research was conducted in Germany in the 1980s. Based on the results, the first fire protec-tion measures were developed and made partoftheGermanFLLGreenRoofGuidelines. There is an opinion that green roofs can reduce the spread of fire, and it was mentioned that some past green roofswereinstalledforthispurpose. This belief is due to the fact that plants are about 95-per-cent water. But what happens when the vegetation dries up? PoorlymaintainedgreenroofswithGreen roof fire in London, U.K., 2018. The fire spread to a nearby green wall but did not affect the roof deck.overgrown vegetation could easily ignite and spread fire. In the private sector, various testing hasbeendoneanddocumented.For example,wehaveseengreenroofs andwaterproofinglayersintentionally exposedtoroofingtorch.However conclusivethosetestingresultsmight have been, they can hardly be used to issueregulation.Amorestandardized, monitoredandreproduciblemethod-ology for testing was needed to scientifi-cally prove what we observe on the roof.To conform to building regulations, roofs coverings are evaluated according toteststandardsCAN/ULC-S107in Canada, or ASTM E108 in the United States. The samples are tested for their ability to resist the spread of flame and downwardflamepropagationthrough thedeck.Eventhoughgreenroof manufacturerssuccessfullytestedtheir assembly following these standards, the test method was designed for a roofing system, not a consistent depth of low organiccontentgrowingmediaand green-roof-specific components. Due to the great variety of plants, their complex configuration and properties that change over time, it is difficult to say whether these testing methods can correctly clas-sify green roofs. This raises the question of whether the existing testing methods are suitable, not considering the fire risks of the green roof itself. This might be why what we see in written regulation issodiverseandconcernsallaspects of green roofs (mineral zones, parapet heights,typesofvegetation,typesof roofdecks,organiccontentofgreen roof media, etc.). www.rcabc.orgl23'