GBA Logo horizontal Facebook LinkedIn Email Pinterest Twitter X 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 you work out the R-value of loose cellulose?

captainsolar | Posted in Energy Efficiency and Durability on

Have roof filled with Insulation and need to work out it’s R rating

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

    Cellulose has an R-value of about R-3.7 per inch.

    I don't know if your cellulose is on your attic floor or between your sloped rafters -- but if the insulation is between your sloped rafters, I hope that you have a ventilation gap between the top of the insulation and the roof sheathing.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |