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Air sealing materials list

shrews01 | Posted in General Questions on


I will be air sealing my attic this week. I’m quite a large guy, so once I get up there I don’t want to be missing anything. Anything I’m missing off my list:


Great stuff gun

Pro great stuff


Foam board 





Loctite spray foam




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  1. Andrew_C | | #1

    Other things that might be useful: utility knife for scoring foam board (you can use 2x4 for straight edge?), tape measure, rags and/or paper towel for wiping off foam and caulk nozzles. If you're using canned foam, you want to be in disposable clothes. A full painter's suit from Home Depot or similar over shorts and a t-shirt is often more comfortable in the attic.
    How are you going to hold the baffles in place? Staples > staple gun.

    You may also want to bring up a small piece of plywood that's stiff enough and large enough to span trusses so that you have a work platform other than just carefully stepping on the trusses.

    Depending on the type of insulation you have, you may wish to have something to move insulation around and/or hold it back, and then to re-fluff the insulation if possible.

    Hope that gives you some ideas that can save some trips up and down,

  2. walta100 | | #2

    Is your plan to slather every crack and joint you happen to be able to see?

    When I was filling gaps I found “fire caulking” to be more effective than the foam and less messy. After I applied a bead and then push the caulk into the gaps with a gloved hand.

    Before you get into the attic you may want to create a pressure differential to the outdoors by taping a box fan into a window and locating the leaks with incense sticks and seal as many leaks downstairs as you can before getting into the attic.

    A few pieces of plywood large enough to bridge the joists and sit on, maybe nice to have.

    If you need to move old insulation out of your way a rake broom and a shop vac could come in handy.


  3. Expert Member
    BILL WICHERS | | #3

    A good cordless LED light, a BRIGHT one, is really helpful. I really like the big LED floodlight Ryobi makes -- it's cheap, it's really bright, and it runs a long time on a charge. Pretty much all makers of cordless tools will have something similar.

    +1 for some plywood! you want 3/4" plywood for this. I like two pieces: one about 1-1/2 times the span between joists, and the other about 2-1/2 times the span. This lets you leapfrog and move around. Make sure to cut everything oversize, you don't want any precision here -- you want to be able to randomly plop down a platform wherever you need it.

    Knee pads and/or a good kneeling pad are helpful.

    If you'll be working in loose fill insulation -- especially blown fiberglass -- I HIGHLY recommend wearing a full tyvek suit (the ones with a hoodie and foot coverings). This will greatly reduce the amount of itching you have to deal with.

    Allow lots more time than you thought you'd need. Attic work is not fun, and it's tedious. I also recommend having some of whatever beverage you like handy. You'll probably be sweating a lot, and you'll get thirsty.


  4. shrews01 | | #4

    Any advice on air sealing where my supply plenum exits the first level through the ceiling and goes into the attic?

    1. Expert Member
      BILL WICHERS | | #7

      I would use the softer "door and window" canned foam here. The softer foam will be less likely to seperate and leak due to vibration of the ductwork. You'll need a heavy application of the stuff, ideally wrapping around both sides of the edge of the drywall a little to help hold the foam layer in place.

      Note that a more elegant solution would be to use a sheet of EPDM to make a sort of flexible grommet, but that would be very difficult to install after the duct is already in place.


  5. paula_builds | | #5

    I am pretty into the duct seal putty - put it around the ducting penetrations as well as around exterior electric boxes. What do people think about the longevity of duct seal putty? I found it really sticky and good for covering wider and narrower gaps. It's supposed to stay soft. Thoughts?

    1. Expert Member
      BILL WICHERS | | #6

      You have to really work this stuff into the gap to keep it from loosening over time and seperating. You can't always see when it seperates, but if you wiggle it you'll feel it move free from the surface. That's not a good air seal :-) I find that the material itself does eventually get hard and fail, but it tends to go 10-15 years or so, maybe more. The more exposed to sunlight it is, the more towards the low end of the lifetime range it will get. This material is very commonly used by electrical contractors to seal around conduits where they go through walls, especially masonry walls.


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