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CICS · Mar 20, 2012

Anyone see anything like this before?

A to Z · Deleted

Moisture?
The heat from the attic would dry off moisture above the rafters last. What time of day was the pic taken?

CICS · Mar 20, 2012

These black streaks are showing up all times of day. I took this about 2:00 today

candrinsulation · Premium Member Roof Cleaning Institute of America

What type of insulation is in the building? When we spray foam insulation undeside of the roof deck you sometimes get these. but yes mostly in the early morning when there is a lite dew or frost on the roof.

Sorry dont have a concrete answer.

Mr Maintenance · Mar 20, 2012

No ridge-vent! any moisture or heat build up cant escape

CICS · Mar 20, 2012

Thanks for the help and suggestions. Is there anything they can do to prevent this? Get a ridge-vent installed.

Construction is way over my head. Reading and talking about it is like foreign language to me.

A to Z · Deleted

Ridge vent will only help if there is a soffit vent, it a ventilation system.

Ugly Shingles LLC · Mar 20, 2012

Mike,

It is just the rafters and the dew its nothing you did, you have nothing to worry about.

I have in the past seen where severe cases of mold ate enough limestone to show slight variances on the shingles and give it a shadow effect. confuse

CICS · Mar 20, 2012

Ugly Shingles wrote:
Mike,
It is just the rafters and the dew its nothing you did, you have nothing to worry about.
I have in the past seen where severe cases of mold ate enough limestone to show slight variances on the shingles and give it a shadow effect.

Thanks, I wouldnt assume the dew would show at this time in the afternoon. This was taken about 2:00 in the afternoon, not to mention this was on the south side of the garage and didnt have much mold on it to begin with.

However, if there isnt any ventilation, I guess it could be dew/moisture....

MJ · Mar 20, 2012

Is just visual? are the shingles doing anything?

I have heard of something called fish mouth when the shingles follow the truss line. I have also heard of thin, defective OSB sheeting contributing to truss lines.

Fish mouth is related to venting, high moisture conditions.

Just thinking out loud. Hope they go away for you.

I had orange rust looking patches show up on a green shingle the other day, rinsed them away, might have been rust from nails? copper flashing? orange slime.

Durham Roof Cleaning · Guest

Maybe when they installed the laminate shingles they ran out of felt paper it looks like the marks start half way up the gable roof.

Mr Maintenance · Mar 20, 2012

Keep us posted ! I would like to know the answer!

CICS · Mar 20, 2012

Im not sure I know the answer 100%, I have a few different options as to what it would be, thanks to everyone on here. I am going to stop by and explain them it's a construction issue.

Mar 21, 2012

CICS wrote:
I cleaned this roof last year and dont know what this is? It is spaced out perfectly as too where a rafter would be...however, I dont know anything about that. All the mold/algae was removed but this is still there....
Any ideas?

Just a guess??? Haven't seen anything like this in my 23 years at this?

Looks like the rafters are holding a moisture line and causing algae to grow back?

Did you try hitting a line with some roof mix?

The Roof Cleaning Institute Of America Training & Certification Forum "Find A Certified Roof Cleaner Directory"

The Roof Cleaning Institute Of America Training & Certification Forum
"Find A Certified Roof Cleaner Directory"