Dissimilar Metals Touch at an Exterior Duct Support

This aluminum duct is bearing directly on a galvanized support and the detail shows an isolation layer that is missing. Can we verify the approved pad and fastener arrangement before final tightening?

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Stop if

Stop before changing structural support, rated construction, equipment handling, specialty materials, weatherproofing, engineered movement details, or manufacturer-specific requirements without the responsible direction.

Watch out

Do not improvise isolation with cardboard, random tape, or material that absorbs water or degrades outdoors.

Check

current drawings and approved details
grid/floor/location and measured conditions
photos showing the installation condition
relevant manufacturer, structural, architectural, or finish information
what has already been checked

Say this to your foreman

dissimilar metals touch at an exterior duct support dissimilar metal contact exterior duct support galvanic corrosion isolation verify the specified isolation material and support detail before allowing incompatible metals to remain in direct contact, especially where moisture can collect. this aluminum duct is bearing directly on a galvanized support and the detail shows an isolation layer that is missing. can we verify the approved pad and fastener arrangement before final tightening?