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: Underlayment

metal roof decking

Return to Underlayment

Return to Archive

Return to Forum

This topic has been closed by the administrator. Comments are no longer accepted.
The plan is to remove the existing roof. Install common trusses with a 4/12 pitch then attach 2x4 purlins on the trusses to attach the metal roofing. Do I need plywood decking with an underlayment on the trusses? Can the underside of the metal be exposed to the attic? Would reinforced plastic placed over the trusses work? I plan on adding blown in insulation and having a ridge vent.
Paul Webb

9/18/2009
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/13897/find/
This will work if: (1) you use a strucutral panel that is capable of handling the purlin span. I would suggest an engineer provide this info based on span tables from the manufacturer whose product you intend to use. You will have to design for snow loads. (2) if you are going leave the underside of the metal exposed, make sure the attic space is well ventilated to help prevent condensation.
Ken Buchinger
NCI Building Systems, Inc.

9/18/2009
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/13898/find/
  • 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