Static field route #19070

What do I do when a rooftop curb is flat but the roof deck is sloped?

Equipment Connections: RTU, AHU, VAV, Fans & Louvers🟨 CHECK FIRSTV190 answer-gap expansion

📖 Verified core answer

A sloped roof with a flat curb can set the unit out of level and create condensate/drain problems. Verify curb pitch adapter requirements before the crane set.

Open in Field Rescue Open category

Field verification checklist

Measure roof pitch and check whether the curb top is level both directions.
Check the RTU/AHU/curb submittal for pitch adapter or level tolerance requirements.
Confirm condensate drain pan direction and drain outlet side.
Coordinate with roofing/structural/GC if curb modification affects flashing or support.
Fix before crane set when possible.

Ask foreman

The roof is pitched but this curb top is not level at [unit]. I checked pitch and drain side. Do you want a pitch adapter/curb correction before the crane set, or manufacturer/detailer direction?

Text to foreman

Route options

AMake the field correction only if it is within your assignment and the approved method.

BHold and document the condition if the fix affects airflow, access, life safety, pressure class, rated assemblies, equipment, or another trade.

CBring the foreman/detailer the location, what you checked, and what decision you need before cover, startup, or rework.

Do not do this

Do not set heavy rooftop equipment on an out-of-level curb and hope the drain pan works later.

Why this matters

An out-of-level unit can overflow condensate, hold water, stress panels, leak, and cause startup/service problems.

Verification basis

Approved drawings/specs, project coordination drawings, manufacturer instructions/submittals, shop standards, foreman/detailer direction, employer policy, and AHJ/code requirements.