One of the more common materials used is asphalt shingles. Older shingles were heavy, and when they failed they crumbled. Modern shingles are lighter because they are reinforced with a fiberglass matrix. Fiberglass is used to strengthen the shingle. These shingles are much thinner and may be more susceptible to surface damage.

Asphalt / fiberglass shingles come in different styles and with various lifetime warranties, ranging from 15 to 40 years. This may change depending on location, ventilation and color. Darker shingles may require more ventilation to prevent heat buildup, that may cause shingles to fail early. Poor attic ventilation can lead to shingles literally baking from excessive heat, and resulting in curling and premature failure.

Three tab shingles are evident by the way key-way lines (slots) run vertically up the roof. The key-ways are the area where leaks are more likely to occur. The shingle below can actually become eroded through, and expose the top of the lower shingle, or expose the felt paper. Strip shingles have no key-ways and are likely to outlast 3 tab shingles. Architectural shingles are the most durable with a double overlay face and heavier weight. These shingles are meant to create an enhanced aesthetic look similar to cedar shingles and be more resistant to wind. Interlocking shingles are seen on older homes and were used before tar strips were used as a self sealant. Tar strips were implemented to help prevent wind damage.

There is very little maintenance with asphalt shingles. Keep trees trimmed back to help prevent rubbing or debris from falling on the roof. If excessive debris does accumulate it should be removed. Painting the shingles is not recommended. The use of any petroleum products is not recommended on the shingles, for it can cause shingles to virtually disintegrate.

Items to look for with fiberglass shingles are as follows:

Normal wear signs

Minor eroding, evident by the granular surface thinning out. Excessive granules may be found in the gutters.

Severe wear signs

Look for poor workmanship by sighting down and up the key-ways and across the rows for straight running lines. If the rows are run too irregularly the previous shingle can become exposed at the key-way and become susceptible to leakage.

In higher wind areas nails tend to hold better. Roofing nails are preferable to staples. If staples are used be sure the staples are parallel with the bottom edge of the shingle. This will decrease the chance of shingles blowing off.

If there is only one layer of shingles, and the roof is failing, replacing the roof may be required. Some areas will allow two layers of shingles to be installed. Check with your local building codes. More layers can add a considerable amount of weight to the roof structure. The average square (100 sq') of shingles weighs approximately 215-400 lbs.

Three tab shingles are not recommended for roofs under a 4 / 12 pitch. Any lower pitch may cause water to back up under the shingles especially with the aid of a strong wind. Some shingle manufacturers allow down to 3 1/2 pitch and require a 4" exposure instead of 5" and 30 lb felt instead of 15 lb felt.

The pitch is the rate of rise to the roof. For example a 6 / 12 pitch would mean every 12" of horizontal run the roof will rise 6".

Supadar, Synthetic Slate

This product has several name brands supadar is just one. A similar product is still manufactured and used in warmer dryer climates. It is essentially a composite roofing shingle to simulate slate or senior. The original company was bought out by a national roofing manufacturer (GAF) and within three years went bankrupt. The product has a history in damp or cold areas with freeze thaw cycles which can lead to severe deterioration and premature failure. There have been cases where the product was improperly mistaken for real slate which has a life expectancy of 60-100 years. This composite procut similar to LP siding or masonite when failure appears may fail within a few years. This product may also contain asbestos if it was installed prior to 1990.