Effectiveness of Mastic Tape for Air-Sealing Ducts
Duct Mastic and Pregnant Wife
We’re in the process of having a ducted heat pump installed along with the associated duct work (attic and basement). The contractor and I had initially discussed using Hardcast Flex-Grip 550 mastic to seal all applicable seems. My wife is currently pregnant and after viewing the SDS I’m a bit concerned as it shows it’s category 1B for “may damage fertility or the unborn child”. The alternative is to use mastic tape (Hardcast Foil-Grip 1403) which doesn’t appear to have any of the same scary warnings as it is zero-VOC. My wife is unable to vacate during the two week install so we’re planning on using the tape instead. Will this be anywhere near as sealed?
.
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Replies
I’ve used mastic in both forms. The stuff in the tub is easier to apply but it definitely stinks for a couple of days so I’d share your concerns. The tape should be fine. Performance will mostly depend on how conscientious the installer is, not on which product you use.