+ Reply to Thread
Results 1 to 10 of 10

Hybrid View

  1. #1
    Join Date
    Nov 2007
    Posts
    4

    Question Cape Attic Insulation

    I have a two story Cape and the second floor is very cold even when heated. I have replaced the windows. There are two bedrooms with walls that back the easment(attic) on either side of the house. The walls are insulated from the attic with the paper on the insulation facing the attic and are covered with card board. Is this a problem? Should I replace this insulation and cover with plastic?

    Thanks

  2. #2
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Cape Attic Insulation

    Here are a couple of photos of the upstairs in my place that is gutted for renovating.
    They might be helpful for illustrating.

    The reason it may be cold up there depends on how much insulation (R value) is placed in the walls ... in the ceiling ... and is there insulation in the floors separating the cold zone and the living space. Insulation should run from the cold area in the floor joist bays and past the under side of the wall into the room a few inches .... if there is no blocking there.

    The paper faced insulation you currently have is actually installed backward. The paper backing is supposed to be a vapor barrier ( weak in my opinion) but it's supposed to be toward the warm (room) side of the wall. Whatever you do ... don't cover this insulation with plastic on the cold side. It would trap moisture inside the insulation severally degrading the performance of the insulation and could encourage mold.
    Attached Thumbnails Attached Thumbnails Click image for larger version. 

Name:	second.jpg 
Views:	1147 
Size:	20.8 KB 
ID:	379   Click image for larger version. 

Name:	second2.jpg 
Views:	942 
Size:	12.8 KB 
ID:	380  

  3. #3
    Join Date
    Aug 2007
    Posts
    1,131

    Default Re: Cape Attic Insulation

    msh,


    If the wall insulation (faced fiberglass batts) is installed backwards (paper facing toward cold attic space).........then there's a good chance that the FG is getting damp/wet from condensed moisture accumulating from the warm side of the wall. This would/will substantially lower it's R-value.

    Also, FG batts are not an effective air barrier. Air movement inside/thru the FG would also substantially lower its R-value. You likely need something more substantial than cardboard as an air barrier/wall covering on the attic side.

    What comprises the ceiling in these bedrooms? Is the ceiling plane actually the bottom of the rafters........ or is there a flat horizontal portion of ceiling?

    If the latter, what comprises this flat portion of ceiling? Drywall or ??? Have seen some less than stellar arrangements and materials used in attic spaces. Such as........ceiling comprised of 1/4" paneling and translucent light panels with hanging flourescent light fixtures mounted above. To top it off, a ridge vent was installed in the roof. The warm air from the house naturally leaked around the lighting panels and was sucked right out the ridge vent. The harder the wind blew, the more the suction. Sometimes the suction was so intense that it tossed the lighting panels onto the floor. His heating and cooling bills dropped over 50% once we corrected the disaster.

    Is there insulation in the ceiling? What type and how thick? (If FG batts again....is the paper-facing toward attic or toward roof?)

    Type of heat is? Is there adequate delivery of heat to this attic? (Might be impossible to determine until the attic is known to be properly sealed up and insulated)


    Are the walls of the house balloon-framed? If so, are/were those stud bays blocked off at the attic floor with something other than the FG batts? (For now....particularly interested in the ones at the gable ends of the house because those are walls in the bedrooms, yes?)

  4. #4
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Cape Attic Insulation

    ****hiller ... thanks for filling in the gaps with your post.
    I was pretty vague .... that's what happens when you try and do it in a hurry.

  5. #5
    Join Date
    Nov 2007
    Posts
    4

    Default Re: Cape Attic Insulation

    Should I put plywood or drywall on the attic side? What R value insulation should I use between the walls.

  6. #6
    Join Date
    Aug 2007
    Location
    The Great White North
    Posts
    4,045

    Default Re: Cape Attic Insulation

    Depending on how old the insulation is that's in the walls .... the modern bats of insulation are higher density ... so for 2x4 walls they have approx. R15. Since heated air rises most heat loss is through the ceiling. So if you have an R15 in the walls it may be adequate .... though it doesn't hurt to put more there.

    If the existing insulation is in good shape and not compressed , ratty , or damp with moisture you can use sheets of rigid foam to cover the insulation on the attic side. What this will do is add a thermo break to the wood studs which will prevent the cold transferring through to the room ... plus it will provide an increase to the overall insulation performance to the wall.

    Hope this helps.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •