Cellulose Spray Insulation Installation

Discussion in 'After Hours Lounge (Off Topic)' started by Mike OConnell, Sep 24, 2003.

  1. Mike OConnell

    Mike OConnell Second Unit

    Jun 14, 1999
    Likes Received:
    Overland Park KS
    Real Name:
    I am currently completing a walk-in closet project (13'x10'). The closet is above the garage and has existing 2x10 floor joists 16" o/c with existing 3/4" plywood for the floor and the garage has an existing drywalled ceiling.

    I would like to insulate the area between the joist and was thinking about using the spray cellulose material.

    A couple of questions:

    How big of holes will I need to drill in the floor to spray the insulation?

    How messy is the "shredder box" when using the system? The instructions say to leave it outside, but I really have no option but to bring it up into the room that I will be insulating. How big of a mess is that going to be?

    Any help or suggestions would be appreciated.

  2. Eric Kahn

    Eric Kahn Guest

    I had blown in cellulose done to my entire house, the unit stays outside and you use a really long hose, you also only have to drill 1 inch holes in the tops of the joist bays
    if you bring the unit inside, you will have a real mess as it generates ALOT of dust while it is running, my side yard was coated in dust from it, but of course it blew away in less than a day
    you also have to have a second person to run and feed the unit
    for a floor, you would be better off asking someone in the business if it can be blown in effectively, you might have to drill holes every few feet, but you might be able to do it in the garage roof and not the floor of the closet, then you can just put the styrofoam plugs in the drywall and mud them over
  3. David Brown Eyes

    David Brown Eyes Second Unit

    Jan 6, 1999
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    I did this for a living for many years. Kahn is essentialy correct.

    Here is how we did floors.

    The unit absolutely must be outside.

    You will need to get a peice of rubber tubeing that is about 10' long and about 1 to 1 1/2' inch inside diameter. This tubeing should be rather stiff but still flexible.

    In the garage ceiling drill holes large enough for the flexible tube to fit through. This should be done along one edge of your project. start the machine, without insulation, and force the hose into the joist cavaty untill it stops, 10'.

    You should get a blower with a hand switch. The switch should have 3 positions (Off, air only, air + insulation). Have the blower set to full strengh and the insulation feed to about 30% or so. You need a friend to feed the machine.

    Start with air only then set the switch to insulation. ALLWAYS KEEP THAT SWITCH IN YOUR HAND as the insulation starts flowing you will feel it start to fill in. If the machine feels like it is struggleing reduce the amount of insulation (25%) slowly pull the hose back making sure the joist cavity is filled. If the hose gets clogged kill the machine imediately, ALLWAYS KEEP THAT SWITCH IN YOUR HAND. Unclogging a hose is more fun than a paper cut even if you pour lemon juice on it.

    It may take a few cavities to, get the feel, but the machine will let you know.

    Make sure when you rent the machine to tell the rental place exactly what you are doing. If you have questions email me at

    [email protected]

    Good luck, oh and prepare to get really messy [​IMG]

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