This weekend I'm going to spend some time in my crawl space tuning up
my duct system (flex duct). By tuning up I plan to ensure runs are
adequately supported and well connected to junction boxes. I also plan
to check for any leaks and repair as necessary. I also want to
insulate the plenum from my downdraft AH that goes from garage into
I see that Nashua has a duct tape that's code approved for flex duct
called 557. How does it hold up over time? I am generally not a fan
of duct tape for ducts but will this stuff actually work?? I also
bought some king size tie wraps to reinforce joint connections.
Also what's the best insulation for T junction boxes and plenums. I
see rolls of 12" self adhesive insulation but R value is only 3 or so.
Would a couple cans of Great Stuff be better at encasing metal
connectors with insulation?
P.S. Unfortunately I've had previous problems with flex duct
seperations due to a lazy contractor who failed to use good tape,
failed to use tie wraps, and failed to adequtely support the flex runs.