On a recent trip up into my attic, I found out that the air conditioner was blowing cold air into the attic. In several places at the AC unit, the foil tape had become unsealed. In the interest of not cooling another room, I plan on re-taping it, but I have the following concerns:
- Does the tape failure indicate a possible failure/fault in the system that should be investigated?
- Is there any surface preparation that I need to do to make sure the tape stays stuck long-term?
Best Answer
On the plus side, the people who did your ductwork made an attempt to seal it! On the minus side, they used tape instead of mastic. Tape can come off, as you've discovered. If you really want to do an A+ job, seal those joints with a generous application of mastic. It's basically a sort of putty-like substance intended for duct sealing.