You may be asking yourself, “What can I expect my roof to look like as this aging
process takes place?” One or more of the following conditions may occur over time:
Curling: As the asphalt hardens over time, the granules which were once securely
embedded begin to break away. Occasionally you may have seen the colored
granules in your gutters. Also, as this hardening advances, the asphalt layers begin
to shrink. Of course, all of this is occurring at a microscopic level and is not
something which will be noticeable on a daily basis. As the asphalt layer shrinks,
it is being countered by the shingle reinforcement, which resists shrinking. We
now have a situation in which the top and bottom coatings are shrinking and the
reinforcement is remaining stable. As a result, the edges of the shingle may begin
to curl over time. In addition, organic shingles may exhibit signs of curling which
might be considered excessive, however, this is not a manufacturing defect and
would be considered part of the normal weathering process of organic shingles.
Surface Cracking: Another manifestation of the normal aging process may
be the development of surface cracks. For example, as the flexibilizing oils of the
asphalt are depleted due to heat, the shingle becomes more brittle, to the point
where surface cracking may appear. The stresses created by thermal shock and
the movement of the roof deck also increase the likelihood of surface cracking.
Blisters: During the course of natural weathering, small bubble-like raised
areas known as blisters may appear on the surface of the shingles. The blisters
may be small and pea-sized or as large as a quarter. The blisters may be open,
exposing the asphalt, or closed. Blisters frequently result when minimum ventilation
requirements are not met.
Staining: Finally, over a period of time, shingles may develop dark brown or
black streaks that are sometimes mistaken for soot, dirt, moss or tree droppings.
In actuality, this discoloration may be caused by algae growth. Although most
roofing systems are susceptible to algae discoloration, it is most readily visible
on white or light-colored shingles.

Dear John

We've encountered lots of ice damming in the the Chicago area.   I agree with you, don't go on the roof now, it's too dangerous.  Attic/roof ventilation and insulation are key factors in the creation of ice dams.  If you're experiencing active leaking into your home now I'd consider using a snow rake w extension pole( while standing on the ground) to pull the snow off the leaking ice dam area.   This might slow down the leaking by exposing the snow/ice melt area and decreasign the amount of snow melt contributing to the ice build up.   

When spring comes, and it will!  Consider installing a quality gutter/downspout snow/ice melt system in the problem areas.  We've used the engineered systems made by WarmlyYour's http://www.warmlyyours.com/en-US/snow-melting/roof-deicing to solve ice dam problems for many of our clients.  See the attached photo of a client's home in Wilmette, Illinois 60091 with a snow melt system actively working.

Once again- stay off the roof ! 

Best wishes

David Roberts 

Roberts Construction Group

This type of staining (algae as the other posters have said) will usually only happen on the North facing surface of the roof.  Same with condensation on your car glass.  Suprisingly, the North facing sky will actually remove heat from a substrate and thus make the roof surface colder.

Colder roof surface = condensing surface.  The moisture combined with the organic component will combine for a great growing surface (that the the rock dust organic component of the shingle).

It is not surprising that it is happeing more after you insulated the home.  By insulating (a good thing), you have reduced the heat sink between the roof and the conditioned space below and therfore made the roof colder in the process.  Colder roof...same as stated above. 

Plenty of roof washes out there that will handled most of this stuff and it does not mean the roof is cooked. 

Make sure when you have a new roof installed that you check for the proper licenses, insurance & accreditations.  Get recent and old references.  Ask if they are going to use Gutter apron at the eaves and drip edge on the gable.  What type of ridge vent will they use?  Will it have a baffle in it to prevent wind driven snow from entering your attic?  Will they use ring-shanked nails for the ridge vent so the ridge vent nails won't back out over time?  Make sure you understand warranties and the fine print of these, especially the pro-rated portion.  Make sure to address both intake & exhaust ventilation, as well as attic ventilation as all of these properly working will dramatically extend the life of your roof and save on energy costs. A great way to educate yourself is to do searches on YouTube or you can visit our website www.croixco.com for helpful ideas and questions.  Check out our Pinterest page for other great pictures and ideas.

I believe Home Depot has some aerosol products that can nearly reach 40 ft, but not positive.

Bee spray typicaqlly has a really far reach or an exterminator. 

Both, more than likely. The mason should replace the masonry products and the roofer should work with the mason to achieve a regletted counterflashing and flash the roof under counterflashings.

Each shingle manufacturer will specify if they have minimum temperatures for install.  40 degrees is a good rule of thumb. Below that, crews may have issues with their equipment (air compressors and hoses) working properly and shingles may not seal, espescially on northern facing slopes.

I would recommend not less than 40 degrees. If the shingles are a dark color in direct sunlight they will seal in one day from the solar radiance from the sun even if temps are low. 

Between 40 and 85 degrees is ideal!