Irregularities of Wood Substrates in Roofing

July 13, 2018

Deck irregularity is defined as being out of plane more than 1/8” in 10’-0” & ¼” in 20’-0”

  1. Longitudinally (eave to ridge)
  2. Latitudinally (gable to gable)
  3. Or Both

Other Irregularity Factors

  • Underlayments
    • Aged material
    • Improper attachment method used

Corrective Action Techniques

  • Ultimately the contractor has the responsibility to go back to the building owner with the irregularities on the particular project prior to installation of panels
  • Inspect the deck for deflection and undulation
  • Properly install the correct underlayment
  • Utilize Above Sheathing Ventilation shim or Glass and Glazing shim where necessary
  • Choose a high quality factory manufactured panel
  • Use proper clip/fastener placement
  • Use proper tools for attachment, don’t overdrive fasteners