Join the MRA | Member Login
Find a Professional
  • Why Metal Roofing?
    • About MRA
    • Benefits of Metal Roofing
    • Compare Roofing Materials
    • Homeowner Testimonials
    • Inspiring Metal Roofing Projects
  • Homeowner Resources
    • Metal Roofing Buyers Guide
    • Resilient Housing Guide
    • Metal Roof Sustainability Guide
    • Above All Else You Need a New Roof eBook
    • MRA News
    • Member Provided Resources
    • 3rd Party Articles
    • Frequently Asked Questions
    • Preparing for Hurricane Season
  • Gallery
  • Visualizer
  • Ask The Experts
    • Energy Efficiency
    • Existing Metal Roof Questions
    • Installation
    • Is A Metal Roof Right For My House
    • Metal Roofing Benefits
    • Product Selection
    • Other
    • Archive
  • Find a Professional
Join the MRA Member Login
Sign Up Log In Add New Topic

TOPIC: Installation

Install over radiant barrier

Return to Installation

Return to Forum

I currently have an existing wood shingle roof with a cathedral ceiling. The shingles are installed from what I can tell over 1/2" fesco board over 1x2's over building paper over 1x t&g decking which spans between wood ceiling joists. A roofing contractor I am looking at using has proposed taking off the wood singles only down to the fesco board, leaving the fesco board in place and building on top of that with: metal shingles over building paper over radiant barrier over 2x2's infilled with 1" of rigid insulation, leaving a 1/2" air space (with a ridge vent and an eave vent at the bottom) over the existing fesco board. My questions: - Doesn't the air space want to be directly below the metal roof above the OSB? Or is it ok to have it below the OSB? - Does the radiant barrier go foil side down or up? - What is the point of leaving the existing fesco board in place and battens in place? My goal is increase the R-value of the assembly but it doesn't seem to me that the fesco is worth the R-value to leave in place. Intuitively it seems like you would want to remove all down to the deck and build up from there. I may then want to start witth 2x4's to get 3" of rigid for a better R value with a 1/2" air space. - I goal would be to achieve an R-30. Thoughts? Thanks!!
Candace Harrison

4/22/2011
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/15808/find/
I am having a tough time figuring out exactly what is going on and what is proposed.Air spaces can be effective located just about anywhere. The same with ventilation. In regard to radiant barrier, the shiny side should face an airspace. I hope this helps. Feel free to call me at 1-800-543-8938 ext 201 All best. Todd Miller
Todd Miller
Isaiah Industries, Inc.

4/29/2011
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/15809/find/
Radiant barriers require an air space to function. If there is not one, all you have applied is a conductive foil. Eric Novotny
Eric Novotny
An informed customer is the Best Customer!

5/2/2011
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/15810/find/

If you would like to reply to this thread, please log in. If you do not have an Ask the Experts forum user account, create one here.

  • About the MRA
    • Member Companies
    • Leadership
    • MRA News
  • For Professionals
    • Join the MRA
    • Industry Resources
    • Upcoming Events
  • Contact
  • Subscribe
©2018 Metal Roofing Alliance. All Rights Reserved. Privacy Policy Terms and Conditions