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: Ventilation

metal to metal: steel joists and metal roof

Return to Ventilation

Return to Archive

Return to Forum

This topic has been closed by the administrator. Comments are no longer accepted.
look to replace an R-PANEL roof with standing seam. The house uses steel framing - not wood. Large area of roof has not attic space due to vaulted ceilings. I can practically 'see' the heat on my ceiling. Looking to gain energy efficiency with modern product and insulation. Questions: 1) running horizontally across the joists is a 'channel' standing at most an inch off the roof joists. the existing roof is screwed to that. Does the space between the joist and the top of the channel constitute the airspace required for ventilation? Doesn't seem like it could remain maintain a constant gap with insulation stuffed between joists. 2) are there any 'special' considerations for metal on metal roofing? ie - thermal barriers or other techniques to reduce thermal transfer from roof to framing to inside room? regards, harry
harry sawyer

7/6/2010
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/14927/find/
Best thing to do here is to create a thermal break between inside and outside. An R-Max board (polyisocyanurate) foam insulation will have the highest R-Value per inch and is used in just such applications. Depending on the roofing system, it can be applied directly over top, or it may require a plywood topper to fasten to. You can get it in 6" thickness which will add around an R-36 to the roof deck. That is probably overkill, however the difference in price is not 6X the 1". I would recommend a minimum of 2" Eric Novotny
Eric Novotny
An informed customer is the Best Customer!

7/7/2010
Share
Or copy this URL: https://www.metalroofing.com/spirit/comment/14928/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