Asked on May 24, 2019

How to put EPDM on concrete flat roof?

Ken EricksonLifestyles HomesMawhelan16


I have a shed with a concrete roof approx 14' x 8'.

I want to put an EPDM rubber roof on it.

I first want to affix OSB sheets to it - but on battens.

I need to know if it needs to be damp proofed prior to affixing battens.

Thank you in advance.

4 answers
  • William
    on May 24, 2019

    You can use a clear concrete sealer just for added protection and prevent it from breaking down in the future. Spalling, flaking, etc. Make sure the battens are pressure treated for moisture resistance.

  • Mawhelan16
    on May 24, 2019


  • Lifestyles Homes
    on May 25, 2019

    To add to Williams’ point, Make sure the battens make a significant amount of slope increase. Another one percent, or even 2% will make all the difference in the world.

    As you know OSB is not water resistant, and I don’t believe it’s available in an exterior grade. So I’d make sure all the exposed edges are not only flashed but also counter-flashed in some areas.

  • Ken Erickson
    on May 30, 2019

    We use OSB sheeting for walls & roofs (pitched) on Habitat for Humanity projects. All of these have moisture barriers and siding/asphalt shingles. As stated above, ensure you build in a slope per local codes and weather expectations.

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