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

1″ Polyiso *without* foil facing??

whiteroses | Posted in Energy Efficiency and Durability on

It’s time to reside my 1960 brick front ranch near Rochester, NY, zone 5 moist (according to NY energy code or zone 6a if you prefer to believe the USDA.

The lot is next to woods, a creek and a bog.

Currently the home is vinyl sided. This was probably done by the previous owners decades ago using Sears, it’s falling off at the gables and loose at the bottom. Walls are 2×4 with kraft faced fiberglass, sheathed with fiberboard. I don’t know if the original wood shingles are still in place. The wall next to the garage door is open, I see lots of nail holes but very few nails.

My guess is there weren’t many nails holding the vinyl siding on, and the fiberboard didn’t hold what nails there were very well.

The walls are cold in winter. The home has been air sealed and the attic insulated with blown cellulose. There is a new ridge vent and the soffits have been opened up.

There may have been termites. There have been carpenter ants from time to time, this year in particular because May and June have been the third wettest on record. There were mice in the past, I found two skeletons behind kraft facing, the fiberglass was completely gone.

I’m thinking the bottom sill may be rotted in places, and the sheathing as well.

I’ve been reading through your site. Very informative.

I’m thinking the best approach at this point may be to tear off the existing vinyl, blueboard, shingles if present, and fiberboard, and remove any existing fiberglass. Reinsulate with new fiberglass. Sheath with 1″ of insulated board, wrap, then install new vinyl.

The brick front is a dilemma. I’d like to leave it alone for awhile until I can afford to have it inspected. I did find one area about 2′ x 4′ where the fiberboard had rotted away. That was replaced with plywood. I don’t know the condition of the rest of the sheathing behind the brick, so I can’t have cellulose packed from the inside until that is determined.

Would furring strips be required over the 1″ insulated board?

Because of the effect on cell phone reception, I want the insulated board not to be foil faced. Any suggestions for products?

Any other suggestions would be welcome. I am on a fixed income and will be hiring a contractor. I need to know what to specify.

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

    Q. "Would furring strips be required over the 1-inch insulated board?"

    A. It depends on what type of siding you intend to install, and it depends on the recommendations of the siding manufacturer. If you plan to install vinyl siding, you may be interested in reading this article: Can Vinyl Siding be Applied Over Furring Strips?

    If you are rebuilding a wall clad with brick veneer, you would not need furring strips.

    Q. "I want the insulated board not to be foil faced. Any suggestions for products?"

    A. The most environmentally friendly option would by polyisocyanurate, which is available with many different types of facings. If you can't find polyiso without foil facing, call up a roofing products distributor.

  2. Tedkidd | | #2

    Hi J. Thanks for directing me to this great thread!

    This is an HRV I've been dying to try which might be a nice option for you. I'd love to get feedback from Martin, Dana, and others on their thoughts:

Log in or create an account to post an answer.


Recent Questions and Replies

  • |
  • |
  • |
  • |