Commercial Roof Drain Cleaning and Repair

Commercial flat roof drains are the most mechanically simple component on the roof and among the most consequential when they fail. San Antonio's summer storm season delivers heavy, fast-moving rainfall - the NWS San Antonio station records multiple events per year with rainfall rates exceeding two inches per hour. A blocked drain during one of these events accumulates water on the roof at a rate that exceeds the structural design load of most commercial decks within 20 to 30 minutes. Drain maintenance is not optional.

Drain deterioration is also a primary leak source on San Antonio's older commercial stock. Buildings from the 1980s and 1990s along Military Drive, Ingram Road, and the older retail corridors on the South Side carry cast iron drain bowls that have been through multiple reroof cycles and multiple clamp-ring replacements. The bowl-to-deck connection on these old drains is often compromised - water passes between the bowl flange and the deck rather than through the drain itself, and no membrane patch in the immediate drain area fixes a bowl-flange leak.

We clean drains as part of annual maintenance programs and as emergency response after storm events. We repair deteriorated drain bowls, clamp rings, and sump pans. We replace drain bodies when repair is not viable. We address ponding conditions by correcting drain height relative to the membrane surface and by specifying tapered insulation packages that redirect drainage to existing or relocated drains.