Roof Drains, Scuppers & Overflows
Drainage is the part of a flat roof nobody inspects until the ceiling is wet. A membrane can be perfect and the roof will still fail if the water has nowhere to go.
What we check
- Drain count and size against the roof area they serve
- Clamping rings — loose or missing rings are a direct path into the building
- Strainer domes, which are frequently missing after maintenance visits
- Scupper throats and conductor heads for blockage and corrosion
- Overflow provision — a secondary path when the primary drain blocks
- Whether the membrane is properly sumped into the drain or simply sloped near it
The Sacramento maintenance cycle
Our rain arrives in concentrated winter storms after a long dry season that fills roofs and gutters with leaves and airborne debris. A drain that coped in April is frequently blocked by December.
Clearing every drain, strainer and scupper before the first storm is the cheapest maintenance available on a commercial building, and it prevents the majority of winter emergency calls.
When drains need adding
If a roof ponds in an area with no drain within reach of the slope, the answer is a new drain or an overflow scupper, not more coating. Adding a drain means cutting the deck and tying into the storm system, so it is planned work — best scheduled with a replacement.
Common questions
How often should commercial roof drains be cleared?
At minimum before the rainy season and again mid-winter. Buildings under mature trees or near heavy airborne debris need more frequent checks.
Do I need overflow drains?
Code requires secondary drainage on low-slope roofs in most configurations, because a single blocked primary drain can otherwise load a roof to failure. If your roof has no overflow path, that is worth addressing.