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Apprentice Q&A · #158

How do I verify the RTU curb gasket is seated perfectly before the crane unhooks?

4th YearRigging & EquipmentRED · Stop / Verify

As the crane slowly eases the weight of the RTU down onto the roof curb structure, walk the entire indoor lower perimeter layout line inside the curb drop using a high-intensity flashlight. * Verify that the heavy rubber or closed-cell foam gasket strip is completely and uniformly compressed between the upper unit frame and the lower curb shelf rail, without any pinches, rolled spots, or open visual gaps where air or rainwater could seep through.

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Plain-English answer

As the crane slowly eases the weight of the RTU down onto the roof curb structure, walk the entire indoor lower perimeter layout line inside the curb drop using a high-intensity flashlight. * Verify that the heavy rubber or closed-cell foam gasket strip is completely and uniformly compressed between the upper unit frame and the lower curb shelf rail, without any pinches, rolled spots, or open visual gaps where air or rainwater could seep through.

Field checklist

Ask Foreman

Hey boss, I’m on rigging & equipment and need verification before I touch this: How do I verify the RTU curb gasket is seated perfectly before the crane unhooks? Do you want me to stop here and check the approved detail, submittal, or inspector/manufacturer requirement first?

Open Ask Foreman

Verify before acting

Use this as training guidance. The foreman, approved drawings, project specs, manufacturer installation instructions, employer safety policy, and AHJ/code requirements always control the final answer.

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Related Field Rescue routes

Before RTU sets on curb — what do I check?Field Rescue · Equipment ConnectionsWhat do I check before an RTU or big equipment gets set on a roof curb?Field Rescue · Equipment Connections: RTU, AHU, VAV, Fans & LouversWhat do I check when landing equipment on a curb?Field Rescue · Equipment Connections: RTU, AHU, VAV, Fans & Louvers

Related mistakes & recovery checks

#165 · Not verifying that a rooftop unit curb is level and flashed before setting the unit4th Year · Installation#007 · Forgetting to account for material thickness when laying out bends1st Year · Measuring & Layout#098 · Using a laser level that is out of calibration and not verifying with a bubble level3rd Year · Measuring & Layout