Subject house is a 2000 model with a 12:12 pitch (I did not climb for reasons I’ll share later)
Photo 1: Exhibits curling and vertical banding (not sure if that’s the right terminology). Can anyone offer an explanation on this, please?
Photo 2: Shingles are releasing in groups and sliding down the roof along with gravity. After sampling at several locations around the roof, I learned the roofing contractor used an air gun to attach the shingles. The nail heads completely or partially penetrated the shingle rendering its attachment marginal at best. The client is at a huge disadvantage and of course the builder is hoping to manage a very distant relationship on this one.
Photo 3: Just a few shingles exhibited this condition. Can someone kindly offer the reason for the wear/failure please?
Search racking method of installation on this board or the web. It’s common but not viewed as the best method by many for obvious reasons.
Curling at the rack seams is sometimes due to tight fit expansion and nowhere for the shingles to go but buckle at the seams. Poor fastening will account for a majority of the problems seen.
Bad install would be an understatement on this photo.
Rip it out and start anew would be my suggestion.
steep pitched roofs and high wind areas use 6 nails per shingle.
They got carried away with these nails guns again and not set right to prevent blow outs.
[FONT=Arial Narrow]The main drawback of pneumatic roofing nailers is their inconsistency in nail depth. Sometimes the heads stick up a little and sometimes the heads tear into the shingle. Another frequent problem is that nails sometimes enter the roof at an angle, which makes the head stick up. Protruding nail heads can tear the shingle above them, and it stands to reason that they don’t hold as well as properly nailed shingles. In my opinion, hand driving roofing nails gives a superior level of quality… it just takes much longer, perhaps two or three times as long.
[/FONT][FONT=Arial Narrow]**A little dab-a-dua of roof cement is also required due to the wind conditions at that steep pitch. **[/FONT]