Return to the Home Repair Forum | Post a Follow-Up


Posted by stevekaren (My Page) on
Sat, Jan 17, 09 at 10:59

I have a 5 year old house with an attached garage. The attic above the garage is insulated but is a common attic for the rest of the house. Should I put a plastic sheet barrier up between the garage attic and the balance of the house? Would this keep the house warmer? Thanks.

Follow-Up Postings:

RE: insulating

Do you know if the main attic is insulated - if not it should be, as should your walls. I don't think a plastic sheet will do much otherwise.

RE: insulating

The most important thing is to make sure the floor of the main attic has insulation up to (I think) R30, the new accepted standard. Before you consider putting up a barrier in the attic, make sure that you do not impede air flow, which could introduce new problems.

RE: insulating

A properly insulated ceiling (ie the insulation is on top of your ceiling drywall when you're looking in the attic) has no need for what you're proposing, and I agree that a barrier is a bad idea. Plastic would not be the right material anyway.

The roof and/or soffits should be ventilated, believe it or not. You want the roof space to be as cold as possible/close as possible to the outside temperature... counter-intuitive as it may seem, you want this situation because you want to reduce the instance of ice damming on your roof, where snow/ice melts and refreezes continually, because the ice can force itself under your asphalt or other roofing, causing potential leaks.

Apart from a decent amount of insulation, you want ventilation, ideally something active like a whirlybird.

I myself plan to add additional insulation to my roof space (blown in) once I have the recessed lighting I want to install in place...

RE: insulating

R50 is what they are now pushing as the acceptacle standard for attics according to CMHC flyers at my local Building supply . Who has that?

RE: insulating

Yes, you want your attic as well ventilated as possible to prevent moisture buildup leading to damp insulation and heat buildup leading to ice dams on eaves. Make sure you have the proper amount of attic insulation. Also, don't neglect doors and windows where a LOT of heat can escape - the site listed below provides some good tips in that regard.

Here is a link that might be useful: Insulation and Weatherstripping

 o Post a Follow-Up

Please Note: Only registered members are able to post messages to this forum.

    If you are a member, please log in.

    If you aren't yet a member, join now!

Return to the Home Repair Forum

Information about Posting

  • You must be logged in to post a message. Once you are logged in, a posting window will appear at the bottom of the messages. If you are not a member, please register for an account.
  • Please review our Rules of Play before posting.
  • Posting is a two-step process. Once you have composed your message, you will be taken to the preview page. You will then have a chance to review your post, make changes and upload photos.
  • After posting your message, you may need to refresh the forum page in order to see it.
  • Before posting copyrighted material, please read about Copyright and Fair Use.
  • We have a strict no-advertising policy!
  • If you would like to practice posting or uploading photos, please visit our Test forum.
  • If you need assistance, please Contact Us and we will be happy to help.

Learn more about in-text links on this page here