GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter Instagram YouTube Icon Navigation Search Icon Main Search Icon Video Play Icon Plus Icon Minus Icon Picture icon Hamburger Icon Close Icon Sorted

Community and Q&A

How do I improve R Value and change to metal on my roof?

Laurence Bishop | Posted in General Questions on

I have an older Pan-Abode home that has cathderal ceilings with minimal roof R Value. I would like to increase the R Value and lay metal roof over shingles. Does anyone have insight on the best way to do this?

GBA Prime

Join the leading community of building science experts

Become a GBA Prime member and get instant access to the latest developments in green building, research, and reports from the field.


  1. GBA Editor
    Martin Holladay | | #1

    Before reading your question, I had never heard of Pan-Abode homes. (For GBA readers who are curious, Pan-Abode is the name of a Canadian company that sells kits for building log homes -- specifically, log homes made from milled logs.)

    To improve the R-value of your roof assembly, you can add insulation on the interior and then install a new ceiling, or you can add insulation on top of your roof deck and then add new roofing.

    Since you are planning to add new roofing, it sounds like it would be easiest to install rigid foam insulation on top of the existing roof sheathing, followed by a new layer of roof sheathing (or strapping) and new metal roofing. Another option is to install nailbase (a sandwich of rigid foam and OSB, like a SIP with OSB on only one side).

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |