• Tips & Techniques for Painting
    Tips & Techniques for Painting
  • 7 Small Bathroom Layouts
    7 Small Bathroom Layouts
  • Energy-Smart Details
    Energy-Smart Details
  • Design Inspiration
    Design Inspiration
  • Deck Design & Construction
    Deck Design & Construction
  • 7 Smart Kitchen Solutions
    7 Smart Kitchen Solutions
  • All about Roofing
    All about Roofing
  • Basement Remodeling Tips
    Basement Remodeling Tips
  • Clever daily tip in your inbox
    Clever daily tip in your inbox
  • Master Carpenter Videos
    Master Carpenter Videos
  • Install a Vinyl Privacy Fence
    Install a Vinyl Privacy Fence
  • 9 Concrete Countertop Ideas
    9 Concrete Countertop Ideas
  • Magazine Departments
    Magazine Departments
  • 7 Trim Carpentry Secrets
    7 Trim Carpentry Secrets
  • Remodeling Articles
    Remodeling Articles
  • Read FHB on Your iPad
    Read FHB on Your iPad
  • Video Series: Tile a Bathroom
    Video Series: Tile a Bathroom

Editor's Notepad

Editor's Notepad

Insulating a Maine Roof with Dense-Pack Cellulose

comments (1) November 8th, 2011 in Blogs
ScottG Scott Gibson, contributing writer

In Portland, Maine, Dean Manoogian is pondering how to insulate the roof of his Cape Cod-style home. It's been constructed without gable, soffit or ridge vents, and Manoogian's plan of attack is to attach 2 in.-thick sheets of rigid foam to the bottoms of the rafters and fill rafter bays with dense-pack cellulose.

More from

Questions and Answers About Air Barriers

How to Install Cellulose Isulation

Forget Vapor Diffusion — Stop the Air Leaks!

Vented or Unvented Attic?

As he explains in a Q&A post at GreenBuildingAdvisor, the rub is what becomes of water vapor that migrates through the insulation in winter. Without a means of venting the moisture to the outside, the roof may be a victim of condensation, mold and decay. To forestall the possibility, Manoogian wonders whether a peel-and-stick membrane should be applied to the roof sheathing and rafters before the rest of the insulation is installed.

The vapor-impermable membrane would presumably keep moisture away from sheathing and rafters. The city has already approved his plans, but is he on the right track?

That's the subject of this week's Q&A Spotlight.

Read the whole article
at Green Building Advisor

posted in: Blogs, energy efficiency, insulation
Back to List

Comments (1)

midmobuilder midmobuilder writes: I am curious about moisture in a similar situation. I have a client with a 27 year old 3/12 modular with a single 2 x 6 rafter that is drywalled, packed with rock wool (I think) and sheathed with 1/2" plywood. After removing the drywall and insulation, we discovered much black staining on the underside of the plywood, along with considerable plywood degradation near the ridge (some had been replaced 9 years ago when the house was reroofed). I am unsure how to put the roof back together after it is reroofed. Closed cell foam to black vapor and insulate well and no insulation? Insulation baffles and a ridge vent (don't know what the ridge is like, it is a modular). Grace Corp says to vent if we cover with ice and water shield (I thought about covering the whole roof with their product since it is a 3/12 and is leaking after only 9 years on these shingles). Any ideas?
Posted: 9:32 pm on November 14th

Log in or create a free account to post a comment.