TinnerFlow™3rd YearRooftop DuctYELLOW · Check First
Outdoor duct should not become a pond. If water is standing on top, check panel pitch/cross-break, insulation/weather wrap, support sag, and approved roof-duct detail before it rots or leaks.
Flat rooftop duct can collect water if the top panel, supports, or weatherproofing do not shed properly. That water adds weight, bows metal, damages wrap, and eventually finds seams or screw holes.
Do not just patch the wet spot. Find why the water is staying there: flat top, sagging supports, missing pitched cap, damaged membrane, or bad slope. Likely recovery is a pitched cap/doghouse, cross-broken panel replacement, support correction, or weatherproofing repair per approved detail.
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.