Had a similar issue myself a couple years back—bathroom vent duct looked fine at first glance, but turns out it wasn't insulated properly. Moisture condensed inside and eventually dripped back down, staining the ceiling drywall. Ended up having to rip out a section, dry everything thoroughly, and then reinstall with proper insulation wrapped around the duct. If anyone's checking their ducts, I'd suggest not just looking at connections but also making sure they're insulated correctly, especially if they pass through unheated spaces like attics or crawlspaces.
One thing I'm still unsure about though: is there a better way to secure ducts to prevent sagging over time? I've seen zip ties and metal strapping used, but neither seems perfect long-term...
Had the same condensation issue in our attic ductwork—total pain to fix. Metal strapping worked okay, but I wonder if something wider or padded might distribute weight better and prevent sagging long-term... just thinking out loud here.
"Metal strapping worked okay, but I wonder if something wider or padded might distribute weight better and prevent sagging long-term... just thinking out loud here."
Interesting thought about wider or padded strapping. Makes me wonder—could the condensation issue itself be partly due to airflow restrictions or insulation gaps rather than just the support method? I've seen cases where ducts sag slightly, creating low spots that trap moisture, but the real culprit turned out to be inadequate insulation or even minor air leaks at the joints.
Also, have you considered the material of the strapping itself? Metal straps can sometimes conduct cold temperatures directly to the duct surface, potentially making condensation worse. Maybe a non-metallic or insulated strap could help reduce this thermal bridging effect?
I remember one job where we kept chasing condensation issues, and it turned out the attic ventilation was insufficient overall. The ducts were fine, but the attic itself was holding too much humidity. Once we improved the attic ventilation, the condensation problem practically disappeared. Could attic ventilation be playing a bigger role here than we realize?
Just throwing ideas around—curious if anyone else has noticed similar patterns or tried alternative materials with success.
Good points about attic ventilation—I hadn't really thought of that angle. As a first-time homeowner, I've been noticing similar condensation issues and started digging into it myself. A few quick thoughts:
- Metal straps definitely seem to transfer cold temps easily... maybe plastic or nylon straps would help?
- Found a spot in my attic where insulation was thin, and sure enough, that's exactly where ducts were sweating.
- Also noticed my attic vents were partially blocked by insulation—clearing that helped a bit.
Seems like it's rarely just one thing causing these issues...
Plastic or nylon straps might help a bit, but honestly, they're not always sturdy enough for heavier ductwork. I've seen them sag over time, causing dips where moisture collects... metal straps with proper insulation wrap might be a better bet long-term.
