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

Retro Insulation and Roof Venting

ebSfo33CMy | Posted in Green Building Techniques on

We live in Massachusetts and recently replaced our roof with Ecostar plastic shingles and the rep forced the roofer to expand our soffit vents and ridge vents as part of the installation. We had a much delayed energy audit in the midst of the installation and the recommendations have put us in the middle of what seems to be an experts’ dispute. The energy consultant says seal the soffits, spray foam and dense pack the closed rafter area leading from the second floor knee wall to the attic flat. The existing fiberglass in those closed areas does not include baffles at the soffit or proper vents, which seem to be minimum requirements if venting is maintained, and it will be very difficult to install such items (the roofer proposal is to pull the fascia and gutters and shove in the vents).

Any thoughts on an appropriate direction? We’ve even considered venting the south roof, sealing the northWhat is the latest thoughts on the venting issue, or is it still up for debate? Certainly there are those installing shingles over SIP roofing which is the ultimate in unvented roof decking.

Thanks, Stuart Warner

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

    1. You tell us that "the rep forced the roofer" to provide ventilation. Does that mean that mean that the manufacturer of Ecostar plastic shingles requires roof ventilation? If so, you have two choices: install the ventilation channels or violate the manufacturer's recommendations (which might void the warranty, if any, and which is probably a code violation).

    2. Certainly unvented roofs can work well, but if a roofing manufacturer doesn't allow it, the code says that you have to abide by the manufacturer's recommendations.

  2. GBA Editor
    Martin Holladay | | #2

    The Ecostar warranty apparently requires installation over a ventilated deck. Here's what it says: "This Limited Material Warranty shall not be applicable if EcoStar determines that any of the following has occurred: ... The Products have been installed over an improperly vented roof deck."

    Read it here:

  3. GBA Editor
    Martin Holladay | | #3

    [Editor's note: Stuart Warner just e-mailed me and asked me to post the following comment]

    In reply to your research: OK, I saw that. And now comes the really confusing part. I couldn't see how they were dealing with new building technology, so I just called one of their tech guys, and he actually said they now recommend venting but not insist on it due to new building technologies! I should have recorded that because the written word will win. But that goes to show some movement on this issue. I'm going to push the rep to nail this down formally for me.
    Best to you,

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |