Stains at vents/roof

[David C. Macy]

Stains around roof top vents.

The roof was one layer standard 3 tab shingle about 10 years old. Gable/moderate slope.
House had soffit/gable/roof top venting. Insulation was loose fill about 6-9 inches. No moisture stains in attic, ventilation seemed to be adequate.

So what is causing the stains around the vents?
How would you report the scenario?

Would an active vent like a power vent be an solution? Or maybe adding more soffit vents. (There were no baffles installed but the insulation was not blocking the vents.

Thanks for the time.

[Kenton H. Shepard, CMI]

Did the rooftops of neighboring homes have the same problem?

[David C. Macy]

Originally Posted by kshepard

Did the rooftops of neighboring homes have the same problem?

I did not look at any other roofs.

[Kenton H. Shepard, CMI]

I don't know. It looks like some kind of airborne particulates coming out of the attic plated out on the shingles. The source of the particulates?

• What's the fuel for the heating system?
• Did any exhaust flues terminate in the attic, including bathroom vents?
• Was there a whole-house fan?
• Was there any discoloration of wall or ceiling surfaces in the living space or of framing or sheathing in the attic?
• If moist air was evacuated through the roof vents, it could be algae, although if those roof vents were galvanized and that was algae, there would be clear streaks on the downhill side from runoff, since algae doesn't like zinc.

[Mark A. Vaage]

Do they have a wood fireplace?

[William Warner]

Looks like over spray pattern to me (like spray paint or some chemical put on the vents). Certainly is interesting what ever it is.

[Brian E. Kelly]

Originally Posted by kshepard

Did the rooftops of neighboring homes have the same problem?

Good question Kenton. Looks like an unexplained anomoly to me. If there was no dicernable damage I might not call it out, or you might recommend to monitor it.

Either way great pic and interesting

[David C. Macy]

Originally Posted by kshepard

I don't know. It looks like some kind of airborne particulates coming out of the attic plated out on the shingles. The source of the particulates?

• What's the fuel for the heating system?

Natural Gas

• Did any exhaust flues terminate in the attic, including bathroom vents?

Possably one bath vent. Termination not visible but may of discharged at a soffit. (Covered with insulation)

• Was there a whole-house fan?

No

• Was there any discoloration of wall or ceiling surfaces in the living space or of framing or sheathing in the attic?

No

• If moist air was evacuated through the roof vents, it could be algae, although if those roof vents were galvanized and that was algae, there would be clear streaks on the downhill side from runoff, since algae doesn't like zinc.

No stains at plumbing stack.

[David C. Macy]

Originally Posted by mvaage

Do they have a wood fireplace?

Yes the home did have a wood burning fireplace. It was at a lower level slab.

[Bob Elliott]

Got any attic pics?



This was a Condo building roof ,so I never got to the attic or roof due to no access.

22 footer not enough, but I did notice the stains.

[David C. Macy]

Originally Posted by belliott

Got any attic pics?

No, there were no visible issues. In the upper attic. Insulation, roof structure and even the ventilation seemed fine.

The lower attic had some indications of past leaking from an upper rrof downspout discharging onto the lower roof surface. (They recently extended)

[Bob Elliott]

Your picture looks like a one time event the way it is all so even .

[David C. Macy]

Originally Posted by belliott

Your picture looks like a one time event the way it is all so even .

They were not shadows as it was cloudy. Maybe I was in the twilight zone!!

[Mark A. Vaage]

Is there a possible leak in the attic from the fire place?

[James F. McKee]

sure looks like smoke damage David but You are not saying anything that would indicate that as a possibility....maybe it was martians...