Roofing, gutters and skylights in Emeryville

A low-slope roof does not shed water, it holds it and drains it, which means the outlets are the whole design rather than a detail at the end. On the converted buildings and lofts around the Park Avenue district the water leaves through scuppers cut in a parapet or through drains set into the field of the roof, and either one blocked turns the roof into a shallow pond within an hour of steady rain. When we inspect one of these we spend most of the time at the drains, the overflow and the flashing where the membrane turns up the parapet, because that is where nearly every failure we are called to has started.

Wind matters more on a flat roof than people expect. There is no pitch for it to run over, so it works at edges instead, lifting a membrane at a seam or peeling back the metal capping along the top of a parapet. Once an edge is loose the next storm gets under it. The repairs are not large if they are caught at the edge stage and they are expensive once water has been tracking between layers for a winter, so on these buildings we care about the perimeter first and the middle second.

The older cottages on the side streets are conventional pitched roofs on small lots, and they have the ordinary problems: tired fixings, a sagging run, an outlet that has not been cleared in years. What is unusual here is how little room there is around them. A neighboring wall a few feet away decides where a ladder goes and where a downspout can sensibly discharge, and it is worth agreeing both before the work is booked rather than on the morning.