Things to look for...

Algae Growth

Algae growth causes a dark discolouration on roofs. The algae is usually brown to black in colour which results in a streaked, dirty looking rooftop. It can be mistaken for soot, dirt or tree droppings, which typically produce only localized discolouration. It's caused by the growth of air-borne algae which deposits on your roof. The good news is that algae growth does not affect the service life of your roofing material. It occurs most often in warm, humid climates such as the Southeast (where algae-resistant shingles are available).

Blistering & Rotting

Moisture or excessive heat in the shingles causes blistering

Rotting is caused by absorption of moisture by the mat at the core of the shingle. This is a common problem with organic-based shingles

Buckling

There are many causes of buckling shingles including: Improperly applied felt, wrinkled underlayment, roof deck movement, spacers not used in between roof deck boards, poor roof ventilation, new shingles applied over old, and rough shingles

Granule Loss

Normally a certain number of granules will be loose, especially after application. These granules are called "riders" and are a normal result of the manufacturing process. Granule loss does not affect the service life of the shingles unless granules can be seen missing on the surface of the shingles, thus exposing the asphalt or Fiberglas® mat.

Missing Shingles

Missing Shingles is a more serious issue caused by improper fastening or exposure to high winds

Damaged Flashing

Damaged flashing can be caused by improper installation on a new roof, drying and cracking on an old roof, denting due to improper nailing, or settling of the structure