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We’re getting hardwood floors installed. They want to use 15# roofing felt under the installation. Is there a more eco-friendly, less toxic option? Thanks!

GBA Editor | Posted in Green Products and Materials on

I have a little over a week to investigate this while our hardwood flooring acclimates. Any help is greatly appreciated.

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  1. GBA Editor
    Martin Holladay | | #1

    I have no reason to believe that roofing felt is "toxic," although some people who install in-floor radiant heating systems avoid asphalt felt because of odor concerns.

    The answer to your question is red rosin paper.


    We've been using red rosen paper for years since the American Lung Association came out in favor of it's use with their healthy house program. no problems with it at all, if your installer is nervous about it just let him use two layers. Its job is to absorb the grit and sawdust under the floor to eliminate squeaks, you could probably use a couple of layers of newspaper to accomplish the same thing but the rosen paper rolls out nice and flat and it's stiffness makes it stay flat as the wood is installed and if any saw dust gets on it it sweeps up nice and clean.

  3. Expert Member
    Michael Maines | | #3

    The other answer is to use no underlayment at all. Unless you have a damp basement, the benefits of using either tarpaper or rosin paper are dubious. Most flooring contractors feel strongly one way or the other. If you do have a damp basement, you should fix that before installing flooring!

  4. Riversong | | #4

    Neither 15# felt nor red rosin paper are vapor barriers. Their purpose is NOT to keep subfloor moisture from the flooring. The purpose of these membranes is to control dust pentration (more important when subfloors were boards rather than plywood), to create a slip plane to allow for differential expansion, and to cushion the interface to minimize squeaks.

    A membrane should always be installed between subflooring and a nail-down wooden finish floor.

  5. Expert Member
    Michael Maines | | #5

    Robert is absolutely correct that none of these items is a vapor barrier. I regressed about ten years in my building science knowledge by suggesting that as a reason to use them.

    However, I have seen every imaginable product used under flooring, on houses of every age, and have tried all the normal options on floors I've installed. Our current floor installer prefers tar paper, but admits that it's out of habit more than anything, and to avoid having to answer questions about why he doesn't think it's necessary. It does make it easy to see how clean the floor is, but I don't buy the concept that it eliminates squeaks. When a board shrinks the groove will rub against the adjacent tongue just as much as is will rub against the floor.

  6. Trina | | #6

    Thanks for all of your answers. I really appreciate the help and the excellent, informative, and lively discussion!

  7. Home Improvement Addicts | | #7

    In 2009 we installed hardwood flooring in 3 bedrooms, using roofing felt as instructed by the store from which we purchased the flooring. I had already become chemically sensitive from the materials we used in the building of a home we lived in previously. When I walked in the first bedroom just after my husband had laid the tar paper and smelled it, I was concerned, but we had other things going on and wanted to get the job done and out of the way, and my husband brushed me off and went ahead and laid the flooring.

    I now suffer from chronic inflammation of both sinuses & other body tissue, and our youngest son has sinus issues and has even suffered from migraines. I'm convinced it's from the off-gassing of the roofing felt under the hardwood, which has shrunk some in spite of acclimatization procedures so there are 1/32 - 1/16" gaps between the boards.

    So we need to either spend thousands of dollars fixing the problem or move. I don't feel good about selling the problem to someone else.

  8. wjrobinson | | #8

    I am not chemical sensitive. That said, we started to use roofing felt one time, sun coming in through windows and the smell was a bear, to bare. Thankful for that sunny day before going forward we ripped up felt and went with rosin paper.

  9. Siffe | | #9
  10. rosebud42 | | #10

    Is it nailed down? I am looking for the same resolutions. Our floor is a engineered wood floor to be nailed down. Right now I have a plastic foam roll that we used under our floor in one of the bedrooms upstairs. After research, this seems to be not the correct underlayment. This new floor will be over a garage and I'd like to have an insulation factor to it... I see the QuietWalk mentioned by Ed Siff ... is this okay to use under a nailed down floor?

  11. GBA Editor
    Martin Holladay | | #11

    Again, I suggest that you use rosin paper.

    I have never used QuietWalk, although I note (from information on this page) that it is a vapor barrier. If you want your floor assembly to be able to dry inward, you don't want a vapor barrier at this location. In some climate zones, a vapor barrier in this location can lead to moisture problems during the summer, especially in an air-conditioned home.

    If your flooring is being installed above a garage, you need real insulation in your floor assembly -- something like cellulose, fiberglass, mineral wool, or spray foam -- not just an underlayment.

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