Attic: leaky ductwork (w photos) - metal tape?


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Old 07-02-09, 07:53 PM
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Angry Attic: leaky ductwork (w photos) - metal tape?

Unfortunately, somebody did a very lousy job with our duct system. I would like to fix it and I think it is a DIY project, but I would like to know the best way to seal those gaps/holes in our duct system.
Is using a metal tape would be my best solution?

Thank you for your help.




 
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Old 07-02-09, 08:40 PM
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that is pretty crummy. Where the collar has pulled out, I would cut the duct back, install a new collar secure the collar with rivets or zip screws, reinstall the duct, tape the inner liner to the collar with METAL FOIL duct tape, tape the insulation to the big duct, paint the entire joint with mastic, make a saddle to go on the bottom of the duct and install a support strap. Ya know since you have to take it apart, add a balancing damper. The others, I would rip out the old and install new using saddles wherever the duct is supported. Once the duct insulation has gotten wet or waterlogged it's worthless.

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Old 07-02-09, 08:52 PM
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Hi snapple, dj has you covered, the only thing I would add is more insulation. I'm not sure where you are, but heat gain or loss is critical in unconditioned spaces. When you add up the surface area inside your ducts that are exposed to attics or crawl spaces, you would like to see more than an inch or so of insulation.

It's an easy place to save.
Bud
 
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Old 07-02-09, 09:39 PM
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Originally Posted by daddyjohn
that is pretty crummy. Where the collar has pulled out, I would cut the duct back, install a new collar secure the collar with rivets or zip screws, reinstall the duct, tape the inner liner to the collar with METAL FOIL duct tape, tape the insulation to the big duct, paint the entire joint with mastic, make a saddle to go on the bottom of the duct and install a support strap. Ya know since you have to take it apart, add a balancing damper. The others, I would rip out the old and install new using saddles wherever the duct is supported. Once the duct insulation has gotten wet or waterlogged it's worthless.

Welcome to Carlisle Hardcast

Rector Seal - The Name You've Trusted for Years
Thank you very much for the detailed answer, daddyjohn. The "joy" of home ownership is taking a toll on me A year ago I didn’t see myself inspecting an attic & trying to fix ducts + all other little things that need to be replaced/repaired/updated. Now, instead of painting my nails & gossiping, I have a new hobby, lol. The house was built 5 years ago, and I have no idea how it passed the inspection – there are so many flaws.
If I had a reliable AC guy, I would ask him to fix our duct system, but I’m afraid to get somebody similar to the one who did the initial installation

Originally Posted by Bud9051
Hi snapple, dj has you covered, the only thing I would add is more insulation. I'm not sure where you are, but heat gain or loss is critical in unconditioned spaces. When you add up the surface area inside your ducts that are exposed to attics or crawl spaces, you would like to see more than an inch or so of insulation.

It's an easy place to save.
Bud
Thank you, Bud, I’m in Arizona; it is going to be pretty hot in our attic... definitely not looking forward to it
 
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Old 07-02-09, 09:47 PM
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I ran some numbers for a small restaurant way up here in the NE and determined that they were loosing 40% of the energy during the summer months to attic heat. We improved their ridge vent and soffit venting and added 6" of fiberglass to their already insulated ducts and saved them close to $1,000 a month. Of course our electric rates are almost double everyone elses, but an attic is a terrible place to put an ac unit.

enjoy
Bud
 
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Old 07-02-09, 09:58 PM
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snapple that's not a summertime repair, it's so hot you'll be tempted to do a hurry up job. for now just wrap some tape and plan a proper job for cooler weather.
 
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Old 07-02-09, 10:53 PM
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Originally Posted by Bud9051
I ran some numbers for a small restaurant way up here in the NE and determined that they were loosing 40% of the energy during the summer months to attic heat. We improved their ridge vent and soffit venting and added 6" of fiberglass to their already insulated ducts and saved them close to $1,000 a month. Of course our electric rates are almost double everyone elses, but an attic is a terrible place to put an ac unit.

enjoy
Bud
Where the heck do you get unfaced fiberglas? I'd like to add some insulation and the only stuff I can conveniently find around here (left coast) is faced.
 
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Old 07-03-09, 05:07 AM
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PoorJohn, r-19 is readily available in unfaced, batts or rolls, 16" or 24". If I need 3 1/2" (hopefully just a little) I strip the craft paper, or remove a bit of the 6" to fit. As in the origional post, they really need to start over, as all seams need to be sealed and then properly insulated. It's a chore, but any any that leaks into the attic is replaced in the house by an equal amount of outside unconditioned air. Like leaving a window open.

ps, I've never found 3 1/2" unfaced, but never really tried.

Bud
 
 

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