"The Worlds Largest Do It Yourself Insulating Website!"
            Itchy's  Do It Yourself Home Insulation
"If you ain't itchin you ain't insulating"



Itchy's Forum

Recent Articles







How To Insulate Circular or Cylindrical Ducts


Don R. from Kansas City, KS wrote:


I have some ductwork in my basement that my wife says needs insulating. I don't know how important that is but I promised her I would get it done. The ducts are round in shape and made of sheet metal. How do I go about getting them insulated?

You have a smart wife.  During the winter you are losing up to 30% of you heat through those things. This is a do it yourself project that you should be able to do in about a day or at most over a weekend unless you have a mile of ductwork.

Measure the circumference of the ducts to be insulated. Next measure the length. Multiply both figures and add another 5%. Next, head on down to the home improvement store and get some R-8 foil faced insulation. You can find it in widths of 2 to 4 feet. If you don't know what I'm talking about it's the insulation with a reflective backing. Pick up some heat rated reflective duct tape while your there. You're also going to need a helper, a utility knife, a couple of ladders (depending on how high your ducts are positioned in the basement), a tape measure and a piece of plywood to use for cutting the insulation.

Before you get started, give the ducts you're about to insulate a good inspection. If you see they are coming apart, use some heat sensitive aluminum foil tape and seal them so you don't have any leaks. You've already measured the circumference of the ducts. Add 2" and cut to required length needed to wrap the duct with a 2"overlap. You're going to run into obstacles, such as running into hangers, so you'll need to measure and cut one piece of insulation at a time as you go.




I've said this before but I'll say it again. Wear a dust mask and goggles when working with this stuff. Cut your first piece, using a utility knife, foil side down on top of a sheet of plywood. Grab the piece you've just prepared and both of you get on the ladders and position it so it wraps with the seam side up. Overlap the duct insulation 2" and don't pull it too tight or the insulation will loose R-Value - you just want it to be snug. Have your helper hold it in place while you tape the seams with the reflective duct tape.

Measure down the length of the ductwork and climb off the ladder and cut another piece. If you run into a hanger, you'll have to cut that piece accordingly. Repeat this process until all of the ductwork has been insulated. Make sure you are taping around the seams or joints where every piece meets.

Related Tips and Advice:

How To Insulate Rectangular Ducts
How To Insulate An Unvented Crawl Space
How To Insulate A Floor In A Vented Crawl Space
How To Insulate Wood Stud Walls

  New Page 1

Resources    Contact Us    Terms of Use    Privacy Policy    Add A Link    Sitemap     

Copyright 2007 - 2014 ,  J. Holt & Associates, All Rights Reserved

Page copy protected against web site content infringement by Copyscape