Roof Drains and Scuppers
The outlets that carry water off a roof, counted by each.
Quick Answer
Roof drains are interior outlets that collect roof water into piping, and scuppers are openings through a parapet or edge that let water drain out. Estimators count them in EA, then add the piping, leaders, sumps and flashings that connect them, and confirm which trade carries each part.
The Full Picture
A low-slope roof has to shed water, and the outlets are what make that happen. Roof drains set in a low point connect to storm piping inside the building, scuppers cut through a parapet to discharge to a conductor head, downspout or open air, and overflow drains or scuppers act as a secondary route if the primary outlet is blocked. NRCA describes low-slope roofs as those with slopes of 3:12 or less, which is why drainage has to be designed with small slopes and sumps.
The unit is EA for each drain body, scupper, leader head and downspout connection, with LF for the downspout or overflow piping, and SF for sump pans and tapered insulation that forms the drainage plan. The drain bodies, clamping rings, domes and extensions are plumbing items, the sump and flashing where the membrane meets the drain are roofing items, and scupper liners, conductor heads and downspouts are sheet metal. The roof plan, roof drainage plan, plumbing riser diagrams, wall sections at scuppers and the specifications in Divisions 07 and 22 are where the scopes are defined.
Install variants change the scope. A primary drain in a sump with an overflow drain nearby needs two piping runs. A scupper through a parapet needs a liner, flashing and sometimes a conductor head, and it may discharge to a downspout that is carried by another trade. Tapered insulation or crickets are shaped around each outlet, so the drain count also affects the insulation quantity. Local code sets how overflow must be provided, which varies by edition and jurisdiction, so confirm it with the plumbing documents.
Pricing mistakes are almost always coordination gaps. The plumber carries the drain body but not the membrane flashing, the roofer carries the flashing but not the piping, and the sheet metal contractor carries the scupper but not the wall opening. Counts also differ between roof plan and plumbing plan, so reconcile them before bid day. Adding an overflow outlet late in design adds EA, piping and wall penetrations at once.
Real Examples
Common Misconceptions
People assume: A drain is a plumbing-only item.
Actually: The drain body is plumbing, but the sump, flashing and insulation around it are roofing, and scuppers and downspouts are usually sheet metal. Three trades touch each outlet.
People assume: Overflow provisions are the same everywhere.
Actually: They are set by the code edition and local amendments that apply, and the design documents show the intended arrangement. Confirm from the drawings, not from a rule of thumb.
Does MeltPlan Solve This?
Partially — adjacentDrain and scupper counts, locations and the related roof areas come off roof, drainage and plumbing plans, and MeltPlan's takeoff service pulls them with AI and has US-based experienced estimators review and adjust them. Which trade carries each part and how overflow is provided stay with your estimating team.
Get drain and scupper counts from your plans →Frequently Asked Questions
What is the difference between a roof drain and a scupper?
A roof drain is an interior outlet that connects to piping, while a scupper is an opening through a parapet or edge wall that lets water flow out.
How are roof drains counted in a takeoff?
In EA, with piping in LF, and sumps and crickets in SF or EA. Scuppers, conductor heads and downspouts are counted separately.
Who installs roof drains and scuppers?
Usually the plumber installs the drain body and piping, the roofer flashes it, and sheet metal installs scupper liners and downspouts. Scope sheets should confirm each.
Where are they shown in the documents?
On roof plans, roof drainage plans, plumbing plans and risers, and wall sections at scuppers, with specs in Division 07 and Division 22.