b'Fortunately, there is some light on the horizon. There are proposed changes (Proposed Change 1790) that seek to clarify some of the issues around overow drains. One of the changes, though, may have an unintended consequence when viewed through the RCABC Roong Pracces Manual lens. I will focus on parts of the proposed changes which are, in my view, most relevant to the concerns raised above: Where the height of the parapet is more than 150 mm above the level of the roof membrane at the roof drain or exceeds the height of the adjacent wall ashing, emergency roof drains or scuppers described in Clause 2.4.10.4.(2)(c) shall be provided. (See Note A-2.4.6.6.(1).) Bold added by the author. This means that the measurement of parapet height is now taken from the level of the drain, not at the parapet. On most buildings with either slope in the structure or a tapered package added, this height will exceed 150 mm. Ive included an illustraon from the proposed change for clarity: BUILDING CODEWheretheparapetheightisgreaterthan150mm, emergency roof drains or scuppers are required above the level of the roof membrane at the roof drain.Remember code is aminimum standard. Figure [A-2.4.6.6.(1).]: An illustration of the proposed code change regarding parapet heights.flowdrains.Oneofthechanges, In combinaon with the requirement for parapet heights to be ve inches (125 mm) or higher though,mayhaveanunintended from RCABC, this means that, in almost all cases on a roof with a parapet, a roof would require consequence when viewed through overow drains. RCABCRoofingPractices the Manual lens.Iwillfocusonpartsofthe proposed changes which are, in my view, most relevant to the concerns raised above:Wheretheheightof theparapetis morethan150mmabovethelevelofthe roofmembraneat the roof drain or exceeds the height ofthe adjacent wall flashing, emergency roofdrains or scuppers described in Clause 2.4.10.4.(2)(c) shall be provided. (See Note A-2.4.6.6.(1).)Bold added by the author. This meansthatthemeasurementof parapet height is now taken from the level of the drain, not at the parapet. On most buildings with either slope in the structure or a tapered package added, this height will exceed 150 mm.Iveincludedanillustration fromtheproposedchangefor clarity; see Figure A-2.4.6.6.(1).In combination with the require-mentforparapetheightstobe fiveinches(125mm)orhigher fromRCABC,thismeansthat,in almost all cases on a roof with a parapet,aroofwouldrequire overflow drains. This requirement has been some-what mitigated by the ability to tie into the primary roof drain (previ-ously not permitted), but the storm drain has to be sized to accommo-www.rcabc.orgl29'