How many layers of asphalt roofing can you  successfully install over previous layers?

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  • 1 month ago
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    answer depends in part on local building code.  AZ allows three layers -- and you use 1/4 inch longer than standard nails per added layer.  FL allows only two layers.  Btw, you should always use ring shank roofing nails, not the old smooth ones.  They are far less likely to pull out in a storm.  [8d ring shanks can be installed, even with old trusses, using a pneumatic nail gun.  If you must hand nail your underlayment [plywood] into old trusses, I recommend using 12d nails -- they'll bend and fail far less often.]  -- grampa

  • 4 weeks ago

    One less layer than when the roof caves in. 

  • T J
    Lv 6
    4 weeks ago

    A total of three is it.

  • 1 month ago

    Where I live 2 is the maximum layers of roofing allowed/7.

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  • Anonymous
    1 month ago

    in my neck of the woods the building departments only allow one layer of roofing

  • 1 month ago

    The standard is two layers then you have to rip it down to the bare wood and start again.    If you try three layers you will find the top layer is not secure and will pull off in high winds.

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