Duct Insulation For Attic - Insulation - DIY Chatroom Home Improvement Forum
Advertisement


Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > Insulation

CLICK HERE AND JOIN OUR COMMUNITY TODAY...IT'S FREE!

Reply
 
Thread Tools Search this Thread
Display Modes
Old 06-06-2018, 10:35 AM   #1
Newbie
 
Join Date: Jun 2018
Posts: 3
Rewards Points: 6
Default

Duct insulation for attic


I have a bunch of duct insulation I got for free. It has reflective foil backing on a fiberglass roll. Can I use this to help insulate my attic if I put it in my rafters? I don't necessarily need more insulation but since it was free I thought I'd take it. I thought it might act as some sort of radiant barrier. Would I just be wasting my time to put it up?
jzcrouse is offline   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-06-2018, 12:16 PM   #2
Member
 
Join Date: Feb 2016
Posts: 2,521
Rewards Points: 2
Default

Re: Duct insulation for attic


Donít think it could hurt


Sent from my iPhone using Tapatalk
BayouRunner is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-06-2018, 01:22 PM   #3
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,682
Rewards Points: 166
Default

Re: Duct insulation for attic


We don't have your location and in some locations installing additional insulation in rafters can be a huge problem.

I assume you have insulation currently in your ceiling and none in the rafters.

Bud
Bud9051 is online now   Reply With Quote
Sponsored Links
Advertisement
 
Old 06-06-2018, 03:15 PM   #4
Newbie
 
Join Date: Jun 2018
Posts: 3
Rewards Points: 6
Default

Re: Duct insulation for attic


Im in Milwaukee Wisconsin. And I do not currently have anything up there. Its kind of unfinished storage space with insulation under the floor boards. Half the up stairs is finished.
jzcrouse is offline   Reply With Quote
Old 06-06-2018, 03:52 PM   #5
Guapo
 
Join Date: Dec 2017
Posts: 5,940
Rewards Points: 11,950
Default

Re: Duct insulation for attic


If there are no ridge vents, gable vents or soffits, I wouldn't insulate. If you have vents & soffits, use foam board behind the insulation to maintain air flow & to avoid trapping moisture.
Guap0_ is offline   Reply With Quote
Old 06-06-2018, 03:53 PM   #6
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,682
Rewards Points: 166
Default

Re: Duct insulation for attic


An unfinished attic should remain uninsulated unless the space is completely converted and conditioned with heat and air circulation in summer. There are guidelines and codes that advise to not add insulation to the rafters as it creates a condensation zone that can cause roof damage.

Do you have any heat ducts up there?

The foil facing also acts as a vapor barrier so using it anywhere up there in a cold climate would require removal of that foil or placing the foil surface against the drywall. In a cold climate the foil facing should go next to the warm surface.

Bud
Bud9051 is online now   Reply With Quote
Old 06-06-2018, 04:09 PM   #7
Newbie
 
Join Date: Jun 2018
Posts: 3
Rewards Points: 6
Default

Re: Duct insulation for attic


I do have air ducts up there. They were wrapped in insulation when i bought the home.
jzcrouse is offline   Reply With Quote
Old 06-06-2018, 04:19 PM   #8
Member
 
Join Date: Nov 2015
Location: Maine
Posts: 10,682
Rewards Points: 166
Default

Re: Duct insulation for attic


In addition to insulation any ducts in an unconditioned attic need to be carefully air sealed. Air leaking into returns or out of supply ducts is replaced by equal amounted through the homes envelope, a double penalty.

If they are flex ducts any connections need to be secure and sealed.

Generally when I hear the attic has board flooring it tells me there isn't enough insulation up there. Wisconsin was listed in the 09 energy codes as requiring R-49 in ceilings and they may have gone onto the 2012 or 2015 codes, unknown from here.

But r-49 is about 14" of insulation which pretty much eliminates any use of that space.

Bud
Bud9051 is online now   Reply With Quote
Sponsored Links
Advertisement
 
Reply

Tags
attic insulation


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Is this fiberglass insulation safe (touching heating duct)? nutlog Insulation 7 12-13-2018 10:33 PM
Insulating your attic Bob Mariani How To Guides 5 07-07-2013 08:49 PM
Metal duct or flex? smokey982 HVAC 6 08-06-2010 06:20 AM
Q's about duct insulation veesubotee HVAC 3 12-13-2008 03:44 PM
Can I add insulation to a 6" flex duct? EE playing with HVAC HVAC 10 06-24-2008 06:07 AM




Top of Page | View New Posts