pitting on west side of steep roof

[John Arnold]

Most shingles on the west side of this steep roof look like the photo. Roof is supposedly 12 years old. The other side looks fine. Any opinions re cause and what, if anything, to recommend?

29095

[Rick Cantrell]

Looks like Hail damage.
Other side was not affected because of wind direction.

[Jim Luttrall]

Moisture in asphalt during manufacture or storage that has been converted to steam and blistered/popped. Google "blister, shingles" and I bet you will see something similar.
Blistered Asphalt Roof Shingles, Shingle Rash Blisters as a Product Defect versus Storm Damage and other defects - Photos and Text Guide to the Diagnosis of Asphalt Roof Failures - How to recognize asphalt roof shingle failure types, black stains on (http://inspectapedia.com/roof/AsphaltRoofBlisters.htm)

That is definitely not hail damage, imho.

[Rick Cantrell]

Moisture in asphalt during manufacture or storage that has been converted to steam and blistered/popped. Google "blister, shingles" and I bet you will see something similar.
Blistered Asphalt Roof Shingles, Shingle Rash Blisters as a Product Defect versus Storm Damage and other defects - Photos and Text Guide to the Diagnosis of Asphalt Roof Failures - How to recognize asphalt roof shingle failure types, black stains on (http://inspectapedia.com/roof/AsphaltRoofBlisters.htm)

That is definitely not hail damage, imho.
I don't think so
If pits are blisters caused by moisture in the shingle during manufacture, I would expect for the shingles on the other sides to show damage also.
Since only a portion of the roof shows damage, seems likely damage is from external source.

Blisters and other manufacturing defects show up over the entire roof, not just a small area.
Hail damage can and often does damage only a portion of the roof.
Depends of how the wing blows.
A glancing blow from a hail stone may not cause any damage

Roof Hail Damaged Asphalt Roof Shingles, Shingle Blister Wear Compared with Hail Storm Damage - Photos, Text Guide the Diagnosis of Asphalt Roof Failures - how to identify hail versus shingle blister damage on roofs (http://inspectapedia.com/roof/HailDamage.htm)
"Blisters on Asphalt Shingles,Should Be Visible In and Out of the Hail Damage Area & on All Slopes Regardless of Roof Orientation & Direction of Hailstones ..."

[Raymond Wand]

Also
Blistering of Asphalt Shingles
CASMA - Blistering of Asphalt Shingles (http://www.casma.ca/en/bulletin_21.shtml)

Effects of Hail on Asphalt Roofing Shingles
CASMA - Effects of Hail on Asphalt Roofing Shingles (http://www.casma.ca/en/bulletin_14.shtml)

Could be an either or case. (hail or blistering)

[John Arnold]

I'm glad you guys disagree. I feel better about kicking it over to a roofer. Thanks.

[H.G. Watson, Sr.]

Looks like surface staple damage to me. Can match up a pattern to what is suggestive of a hand-held spring loaded staple 'gun'.

Signs (banners/tarps) from agents/developers on roof - seen that stupidity more times than I can count, esp. with turn-over with so many defaulting & BK'ing in the last down-turn...

Which exposure faces the street (or can be seen from afar-major roadway)? How high? Reason asking...could have been from overzealous, ('Clark Grizwald-esque') Holiday decorating (a-la-light strings/lighting 'mats' secured with staple gun) such as spider webs, lighting grids, etc.; removal, plus some of those more recent freeze-thaw-cycle winters.

What Grandpa & Dad might have gotten away with when the non-fiberglass asphaltic 3-tab roof covering was near EOL were present - fiberglass/composite unforgiving, esp. when cold; Have seen by DIYers and hired holiday lighting decorting 'companies' doing such damage and poof-gone long before the HO realizes damage to the roof covering.

So many of the decorating "jobs" seen in the priort decade had me shaking my head - light strings stapled to roofs, motorized do-dads 'mounted' upon same - fan-driven-lighted "balloons" mounted with myriad extension cords stapled up there...sheesh, might as well gone up there wearing spikes and started 'clog dancing'.

Suppose hail could also have contributed, but I'm seeing a diagonal pattern running down and to the left of pic from the upper right, that to me looks like a staple gun was used - just that area/line of the roof or throughout the exposure field?

Another WAG, esp. if side or rear exposure - signs of a SAT-TV dish having been there? (stapled cable to/from same) - sadly seen that too often too!

Any signs of partial re-roof/repair, indicating a temporary tarp over an area might have been secured?

Since some of the patterned seem to be at the very bottom edge of a tab, did lifting same and slipping in a mirror indicate evidence of holes (such as from staples?) were present (light passing through)?

[Jim Luttrall]

I don't think so
If pits are blisters caused by moisture in the shingle during manufacture, I would expect for the shingles on the other sides to show damage also.
Since only a portion of the roof shows damage, seems likely damage is from external source.

Blisters and other manufacturing defects show up over the entire roof, not just a small area.
Hail damage can and often does damage only a portion of the roof.
Depends of how the wing blows.
A glancing blow from a hail stone may not cause any damage

Roof Hail Damaged Asphalt Roof Shingles, Shingle Blister Wear Compared with Hail Storm Damage - Photos, Text Guide the Diagnosis of Asphalt Roof Failures - how to identify hail versus shingle blister damage on roofs (http://inspectapedia.com/roof/HailDamage.htm)
"Blisters on Asphalt Shingles,Should Be Visible In and Out of the Hail Damage Area & on All Slopes Regardless of Roof Orientation & Direction of Hailstones ..."

I agree that hail damage is usually limited to portions of the roof, but blisters, especially the small BB size that I see in the photos can be only on one face or a portion of the roof for at least three reasons: solar exposure will be most intense of the west face causing blisters to form and pop rapidly where the other faces may offer a less intense exposure and reaction. The west face shingles could have been applied at a different time under different weather conditions, and obviously the shingles on different faces will be the most likely to be from different batches.

Maybe hail is different in the OP's part of the world, but here, hail large enough to do damage beyond scuffing a little granules off will leave larger pock marks. I have never seen hail cause the small protrusions of asphalt.

Regardless, punting to a roofer takes the monkey off your back and establishes there is a visible defect to the client.

[Rick Cantrell]

solar exposure will be most intense of the west face causing blisters to form and pop rapidly where the other faces may offer a less intense exposure and reaction.
That's possible.