Dark streaks on shingles - are they worn out?

[Mike Klein]

The roof of my house has many vertical "streaks" in the asphalt shingles, evidently caused by the removal of the light-colored granular material from the shingles which exposes the darker matrix. The streaks start in a small region then spread downward and outward for about a foot - sort of like the splat of a juicy insect against a windshield. Much of the granular material ends up in the gutters. This has mostly occurred within the last year.

Is this normal wear-and-tear, or an indication that the shingles are overly worn? The re-roof job is about 10 years old. None of the other houses in the neighborhood show this, but ours is the only light-colored roof. Otherwise everything is fine - no cracks, loose shingles or leaks. We live in Marland, weather/sun not too extreme...

I greatly appreciate any advice,

Mike

 

[tbasc]

Might be mildew.
There are sprays, or you could put a strip of zinc near the ridge.
TB

 

[cowboy]

it is only a cosmetic problem at this point

it will be a "genuine" problem at the first sign of a leak

at the first sign of a leak, replace roof, as it will get worse in a hurry

but you are fine for now

 

[Joshua Putnam]

The roof of my house has many vertical "streaks" in the asphalt shingles, evidently caused by the removal of the light-colored granular material from the shingles which exposes the darker matrix. The streaks start in a small region then spread downward and outward for about a foot - sort of like the splat of a juicy insect against a windshield. Much of the granular material ends up in the gutters. This has mostly occurred within the last year.

Is this normal wear-and-tear, or an indication that the shingles are overly worn? The re-roof job is about 10 years old.

This is often an indication that the shingles are getting hard and brittle. If it's just spots and streaks, but otherwise the roof looks OK, I wouldn't worry about it just yet.

But I also wouldn't suggest waiting for signs of actual leakage to replace the roof -- that can end up with an emergency re-roof in nasty winter weather, or a homeowners insurance claim for lots of water damage. When the aggregate loss gets more widespread, or the shingles start curling up at the corners, I'd go for a planned re- roof before it's an emergency.

Also, if the existing roof is failing well before its planned life, I'd check on ventilation -- is the roof getting too hot, shortening the shingles' life?

 

[Mike Klein]

Thank you all very much for your suggestions!