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

Insulating and Adding a Rainscreen on a Wall Without Siding

Jay Thomas | Posted in General Questions on

Hi there, I am located in Zone 6, Western NJ. I realized I have one wall with no siding – just #15 Felt over plywood over 2×4 studs w/ R11 fiberglass. The rest of the house has stucco – but they skipped this wall. As you might imagine this wall gets cold in the winter. You can clearly see the thermal transfer from the studs to the room on the IR camera. 🙂

Since there is no siding, I think it would be easy to add external foam. It looks like they just painted the felt. I assume I would need a rainscreen on top of the felt – is that right?

After that I am planning to attach 2 inch foam (wall is exactly 4×8 tall so that should be easy!) and then have someone do an EIFS finish. Does that make sense? Or is there any reason not to add the rainscreen? Thanks, Jay

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. Kyle Bentley | | #1

    Are you saying that of the whole house, they left one wall unfinished and simply painted the building paper, and called that done?

  2. Jay Thomas | | #2

    Yes. Put some textured paint on it to make it look like it was stuccoed. Somehow its stayed together for 30 years!

    It is possible the stucco failed and was removed more recently - but I dont have any records of it. I also didn't notice it was off for my first two years!

    The plans say there should be stucco there.

  3. GBA Editor
    Martin Holladay | | #3

    Perhaps you meant to write that one wall has no siding (or cladding).

    "Sheeting" is a misspelling (the actual spelling is "sheathing"), and it refers to the plywood layer on your house.

    1. Jay Thomas | | #5

      Yes - you had it right. No siding. I'll update the title. Thank you.

  4. GBA Editor
    Kiley Jacques | | #4

    Hi Jay,

    Here are two articles that address the issues you are tackling: Insulating Walls in an Old House With No Sheathing and All About Rainscreens.

    1. GBA Editor
      Martin Holladay | | #6

      Jay's house has sheathing, so the article titled "Insulating Walls in an Old House With No Sheathing" is irrelevant.

      EIFS contractors are responsible for the flashing details -- and after the EIFS crises of the 1990s, most EIFS contractors have to jump through a lot of hoops to obtain insurance. That's why EIFS contractors are generally competent these days, and why their warranties are worth something.

      If you want to install conventional cement-based stucco rather than the synthetic stucco used by EIFS contractors, I recommend the inclusion of a rainscreen gap. For more information, see "To Install Stucco Right, Include an Air Gap."

  5. Jon R | | #7

    Some info on using EIFS. Note the option of "wrinkled paper" in Fig 6.

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |