How to Seal Exposed Ductwork- DIY Weatherization Solutions from Green Dream Group

[danstheman3]

These instructions are incorrect: If you're going to use UL-181 tape, it should go on before applying mastic. Then the mastic should completely cover the tape, especially at the edges.

Most of the time, the tape is unnecessary. It helps to cover large holes, and add some strength to the joint. But the fiber-reinforced mastic is key.

The mastic should also be applied more thickly than shown in the video. It should be applied at least as thick as a nickel.

[ak99372]

I use the aluminum foil underneath the mastic.... especially with bigger holes. I don't see the point of putting it on top

[EmeraldBendInvestmen]

Great!

[uodet]

Since you're using latex sealer you may use a damp cloth to clean up before hand - Tape joints with blue masking tape to keep it neat REMOVE PROMPTLY - Some people ARE ALLERGIC to latex. Ask 1st. it DOES OFF-GAS - You may eliminate the last layer of tape, it's overkill & it's doomed to failure - See videos about how to seal ducts on my channel - It's simple & gives you a GIGANTIC payback, more air out of the ducts - homeowners MIGHT get lucky & find sealer at home centers or CALL a contractor

[d1incharge]

I dont use the tape, our attics down here get so hot and humid, even UL tape seems to fall off. Rubber gloves, handfull of mastic..........that stuff is the bomb......

[linden587]

Very informative. great video. Thanks!

[cigg4000]

Thank you. Just out of curiosity where is this tin knocker wanna be from? does alot of shit differently then we do in the northeast

[thejeztar]

man i can name about ten things wrong with this video

[cigg4000]

And on a sidenote....the matter of sealing exposed spiral is purely of an aesthetic nature. We leave it up to the customer, some prefer not to see the messy grey #33 duct seal on the exposed spiral..

[cigg4000]

Chompychomps your comment about someone using a start collar is clearly wrong. Within the first 30 seconds of the video u can clearly see when he shows the black marks on the wall that they came from a tab collar or also known as a 97LS..or what i believe u ment as start collar. It wasnt tightly installed so the black marks are from the spaces between the tabs.

[101heaters101]

"crimped around to tighten it"....no they crimp the pipe so that a 6 inch pipe will connect into another 6'' pipe...and secondly, you put the tape on the joint 1st, then use mastic over the tape...over time tape comes off...so mastic should be applied over the tape, and you shouldnt see the tape nor the writing on the tape. You are right about sealing it no matter if its exposed or not...all in all good video, 4 stars

[chompychomps]

Well, it looks like someone failed to use a start collar here. If that duct is merely butted up to the plenum, all that is needed is a collar with a self-adhesive gasket and some mastic to fix it properly. Easy, squeezy.

[cigg4000]

Just a quick tip. If you are running exposed ductwork you dont want it to be sealed. Hence the reason for it being exposed. Now if your running duct thru walls/ attics /chaisses etc. Then you will seal it so the air stays either hot or cold whichever the unit is calling for. Please think about your actions before you post videos giving wrong information.

[GreenDreamGroup]

To be accurate, all ductwork everywhere should be sealed. Exposed ductwork is not supposed to leak air, it just means the effort to hide it hasn't been made. In addition, ductwork in 'unconditioned' spaces, like this basement, should be insulated, which we don't go into. Feel free to pursue training in building performance to learn more.