What are some shake and shingle installation defects?

The ones that come to mind are

  • underlayment for shakes instead of interlayment
  • failure to offset joints adequately
  • failure to leave adequate spacing
    *]excessive exposure
    Just looking for installation defects here. Anyone… ???

I can think of a few:
Nails too high, so the shakes flip up in a wind
Nails too low, exposed
Exposed nails between the shingles
Nails too short
Spacing between the strapping too wide
Split shakes or shingles
Nails in the valley
Roof pitch too low, lower than 4:12

There’s more and I’ve tried most of them, back in the 70’s when shakes were popular. Shake roofs are rare nowadays. Old-growth red cedar is mostly gone, they are heli-logging the last few patches now. People are more aware of the fire hazard too.

John Kogel

Hi Kent, there are ton of them in the on-line roofing course