Insulation options

Discussion in 'Insulation and Radiant Barriers' started by pfrost, Feb 25, 2013.

  1. Feb 25, 2013 #1




    New Member

    Feb 25, 2013
    Likes Received:
    Anyone who can comment on my DIY Project it would be much appreciated. I am also considering making my home a passive house. Going to take a while with many stages:

    Current stage of progress:
    Existing House: 3 level split with carport. built 1962 NORTH VA

    First level: Basement with thrid level above it and second level next to it. 8" block Below Grade to 4" block with brick veneer OG. Finished, but no insulated.

    second Level: Living/ktch/din/carport over dirt crawl. Brick N Block to stick. Fiberglass Insulation in stick portion

    Third Level: Beds n bath Stick c/ almn siding. Fiberglass Insulation.

    Addition: On second level. 18" crawl over old concrete patio/carport. Pressure treated floor joyce by code.
    Inspections passed: foundation, framing, plumbing and elect.
    Unfinished: Siding, mechanical, drywall, flooring.

    Addition is L shaped with an open floor plan. Carport closed in and wraps around the back. Back wall of existing to come out someday. LVL header & knee wall in place. Dried in with OSB & TYVEC.

    The new roof extends from the existing ridge line over the old roof, making the thermal boundary difficult to pic. Considering removing old roof sheathing to make it easier to create the boundary, but not sure if it is necessary.

    Attics: All are connected, but step up with a knee wall b/w 2nd & 3rd level with stair hall in the middle. Existing attic's are fiberglass insulated.

    I have had a home energy audit with blower door test. Waiting for the results.

    Now for the questions:
    Are my following plans the best options for Insulating at each stage and which should be done first?

    Starting bottom up:
    1. Finished basement: Really don't want to tear up the basement at this point, but I think it is the place to start.
    a. Slow rise closed cell foam b/w block and finished wood panelling/drywall in bedroom.
    b. Closed Cell Spray foam in band/floor joyce along perimeters only. Need to remove sections of ceiling to access.
    2. Crawl spaces:
    a. Dirt Crawl existing: No french drain or sump. It is dry in terms of good grading on exterior.
    Install a vapor barrier from Clean Space encapsulation with closed cell spray foam from band joyce down and over vapor barrier onto the floor, only on the one exterior block wall. Will turn the corners a few feet for thermal contact or whatever they call that third law. Addition crawl surrounds old dirt crawl. Only one wall in old crawl is on the exterior.
    Do I need a mechanical system in the crawl. I recall reading something about an inducer, maybe for humidity?
    b. Addition slab Crawl: Same treatment, with vapor barrier wrapped around footers and all three walls. Closed cell foam.

    3. Existing walls: I plan on residing and removing old cardboard sheathing.
    Option 1: tape, caulk, or can spray foam joints and follow with tight packed cellulose.
    Option 2: Closed cell spray foam$$$$$
    Option 3: keep old fiberglass and seal tight with ridgid foam board and tape. Furring strips for screen then siding.

    4. Addition walls:
    Option 1: Closed cell sp. Foam
    Option 2: seal gaps with caulk, tape, or canned foam and tight packed cellulose

    5. Attic: Floor or ceiling?
    A. Floor: closed cell spray foam or blown cellulose with soffit and ridge vents. Seal all joints and chases with canned foam or tape.
    B. Ceiling:
    1. Vented soffit/ridge with baffles and closed cell sprayed foam.
    2. Vented with Ridged radiant barrier foam board facing roof and fastened to the top chord/joyce. Air tighten by taping joints or canned foam.

    6. Any thoughts on “Foam it Green” and doing the spray foam yourself. I have read all the warnings about temp control and temp's during application process. I think I can still do it. It's still expensive though. Can I get the same energy savings/ R factor without the spray foam?
  2. Feb 25, 2013 #2




    Contractor retired

    Nov 4, 2010
    Likes Received:
    Welcome to the site.
    Basement; Before doing anything, check condition of perimeter drain and the exterior waterproofing on the foundation are 50 years old. Build a 2x4 wall 1" away from the concrete with poly under the bottom plate and insulate this wall and the floor outside this wall with vapour barrier behind the drywall.
    Crawl space, Others may say to seal it but I am a non believer. Sooner or later, a roof will leak or plumbing breaks or toilets overflow or what have you, you will get water in the crawl space. I believe you are far better off to insulate the floor and have good ventulation below. And again consider the perimeter drains.
    Existing walls. If you have fibreglass and vapour barrier on the inside you do need gaps in the outside sheeting behind the housewrap. Housewrap stop water and wind from intering but allows water vapour out.
    The old roof under new roof should have some hole to allow air movement from soffets to ridge.
  3. Jun 16, 2013 #3




    Junior Member

    May 31, 2013
    Likes Received:

    Quite a few points of bad information in that link.
  4. Jun 17, 2013 #4




    Housebroken Staff Member Admin Moderator

    Dec 17, 2005
    Likes Received:
    Say goodbye to the spam...we eat good around here.:D

Share This Page