Roof Drain Installation

What This Service Involves

Flat commercial roofs in Western Washington must handle sustained downpours and atmospheric-river events without ponding, and inadequate drainage shortens the life of any membrane. We install and upgrade internal roof drains, retrofit overflow drains, and correct slope so water reaches the outlets. Proper drainage protects both the roof assembly and the structure below from the weight of standing water. Each drain is flashed and sealed into the membrane for a leak-free connection.

Benefits

Drainage sized for sustained regional rainfall; eliminates ponding that degrades membranes; reduces structural load from standing water; overflow protection guards against clogged primaries; watertight membrane-to-drain connections

Our Process

1) Evaluate roof slope, ponding patterns, and existing drainage; 2) Size primary and overflow drains for local rainfall loads; 3) Cut in and plumb the new drains; 4) Flash and seal each drain into the membrane

What Affects the Cost

Number of drains and overflow requirements; plumbing routing and connection distance; membrane type and tie-in detailing; whether slope correction or tapered insulation is needed

Best Time of Year

Installation is best scheduled in the drier summer months so the roof stays open and watertight during the tie-in work.