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
- Severe eroding
- Fissures in the surfaces (alligatoring)
- Cracking through and across the tabs.
- Holes through the shingles
- Curling of edges of the shingles
- Missing shingles
- The key-ways wearing through the shingle
beneath.
- Exposed shingle matrix worn through
surface, i.e., fiberglass, felt paper
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.
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