The most common types of roofing materials for residential structures
are: asphalt shingles, wood shingles and shakes, metal roofs, tile, slate
and composite coverings.
ASPHALT ROOFS: This is the most commonly used and least expensive roof
covering material. Asphalt roofing
materials consist of either a rag fiber or a fiberglass mat impregnated with
asphalt and covered with colored mineral granules. A wide variety of designs,
weights, colors and sizes are available.
Asphalt roofs show their age when the mineral granules wear off, reveal the
black asphalt and the corners and edges of the shingles begin to curl and crack.
This is an indication that the asphalt composition has begun to dry out and
lose its weather-proof seal. When only a few shingles show the above type of
wear, the simple and less costly replacement of worn out shingles may be all
that is needed. If one out of every five to ten shingles shows this wear and
aging, it is may be time to re-roof.
WOOD SHINGLES AND SHAKES: Shingles made of cedar, cypress or red wood
are highly rot-resistant and may last 30 to 35 years if properly installed and
maintained. The best wood roofing materials are pressure-treated with wood preservatives.
When considering home safety, it is wise to note that wood shingles and shakes
are more highly combustible than the other roofing materials available. If a
wood shingle is your choice, look for one treated with fire-retardant chemicals.
As wood shingles and shakes age they may shrink and form gaps between each
shingle. They may also become brittle and offer less protection from the elements.
As is the case with asphalt shingles, if only a few wooden shingles show this
wear and tear, replace the individual shingles.
METAL ROOFS: Metal roofs are highly resistant to damage from the elements
and may frequently last 40 years or more. They are highly fire resistant and
require little maintenance. Small damaged areas can be repaired with patches
of similar metal. The materials used in a metal roof may include copper, tin,
steel, aluminum, lead or an alloy combination of one or more of these metals.
TILE, SLATE AND COMPOSITES: Roofs made of slate or tiles composed of
either clay or concrete are perhaps the longest lasting available. They frequently
survive more than 50 years, and normally require little or no maintenance. In
addition these materials are extremely fire resistant. When one of these roofs
does need replacement, however, the cost can be very high.
Tiles offer comparable benefits to slate but come in a more decorative and
cosmetically-pleasing variety of colors, textures, shapes and sizes. Tiles
can be glazed or unglazed. Slate typically comes in only black, grey or
of Roof Coatings
Roof coating has become an effective and popular method of extending the life
of a roof. It can add protection against weather and fire, may increase energy
efficiency and can even be used to change a roof’s color. But is is no substitute
for repairs to a defective or worn out roof. Consequently, roof coatings should
be applied before any serious roof deterioration occurs.
Maintenance roof coatings or cold process roof coatings are ready-to-use
protective coatings for roofs and other areas exposed to the elements. They
come in a liquid or semi-liquid state and are applied by brush, roller or spray.
Roof coating professionals generally use coating materials that can be grouped
into the following five categories:
ASPHALT-BASE COATINGS: Asphalt-Base Coatings come in three different
types: emulsion, solvent or aluminum pigmented.
• Emulsion Type Coating is adaptable over asphalt built-up roofs, metal
roofs and those similarly composed, provided there is adequate drainage. When
applied in the proper thickness, it chalks slowly and doesn’t blister. It can
be applied over a damp surface and will not flow under heat. It does require
temperature and humidity conditions that permit thorough water evaporation before
the coating can be subjected to rainfall, freezing, or standing water. Emulsion
coating requires a clean and a primed surface for good adhesion.
• Solvent Type Coating can be applied over asphalt, composition, asbestos-cement,
metal and masonry roof surfaces. It can be applied on a clean, dry surface over
a wide temperature range and is relatively free of wash-off problems after a
short drying period. It has good water resistance and may not require a primed
surface for good adhesion. Solvent coating may flow under extreme heat and is
combustible. It is susceptible to blistering if applied over a damp surface
or any material containing moisture.
• Aluminum Pigmented Coating consists of flake aluminum particles dispersed
in solvent type asphalt coatings. It can be applied over asphalt, composition
or metal roofs having adequate drainage and provides a reflective or decorative
surface. The coating’s reflectivity helps improve a buildings energy efficiency
by deflecting ultraviolet rays and reducing the roof’s temperature. The cost
of this coating is higher than most and its applications over low melt asphalt
roofs can result in discoloration and scaling. It is susceptible to blistering
if applied over a damp surface or any material containing moisture.
ALKY-BASE COATINGS: Alkyd-base coatings can be applied over metal,
composition or masonry roofs that have adequate drainage. They perform the same
functions as aluminum pigmented coating. Although alkyd-base coatings cost more,
they are often selected because of their decorative versatility. They will not
flow under heat and are susceptible to blistering if applied over any damp material.
Alkyd-base coatings tend to discolor and/or split when applied over low melting
point asphalt and are combustible.
• Acrylic Latex Coating: Acrylic latex coating comes in liquid form
and is available in various colors; white being the most common. White and other
light colors reflect the sunlight, keeping the interior of a building cooler
and conserving energy during warmer months.
• Refined Coal Tar Coating: Refined coal tar coating is used for re-coating
tar and gravel roofs. In preparation, the gravel must be removed and roof surface
broom cleaned. Proper protection requires approximately seven gallons per 100
square feet, and gravel should be re-applied over the coating. It is self-heating
at warm temperatures, is very water resistant and can be used where the roof
is subject to standing water. Refined coal tar tends to be brittle in cold weather,
and its use is restricted to relatively flat roofs.
• Flexible Ceramic Coating: Flexible Ceramic Coating is a relatively
new addition to the roof coating business. The primary attraction of a
ceramic coating is its insulation properties that allow for energy efficiency.
As a result of its flexible nature, ceramic coatings help seal cracks
and hide surface flaws. It has proven particularly popular in warmer climates.
The Roof Inspection
Some roofing contractors provide inspection service free-of-charge in an effort
to solicit work. You should expect a roofing inspector to pay close attention
to roof penetrations, flashings and distress areas such as blisters, curling
and cracks. Tell the inspector about any problems you yourself may have noticed;
particularly during the rainy or snowy seasons.
The inspector's findings will likely put your home's roof into one of the following
• Materially sound—not currently in need of repair or maintenance
• In need of patchwork and coating.
• Requires resurfacing with a new membrane.
• Deteriorated to the extent that it requires total removal and replacement.
Hiring a Roof
If you determine that you will need some roof work done, take the time to evaluate
the roofing contractor who may be doing the job.
The following guidelines will help in you choose a qualified, experienced roofer:
• Check for a permanent place of business, telephone number, tax I.D.
number, and (where required) a business license.
• Insist on seeing copies of the contractor's liability insurance coverage
and workers' compensation certificates. Make sure the coverages are in effect
through the duration of the job.
• Look for a company with a proven track record that readily offers
client references and a list of completed projects. Call these clients to find
out whether they were satisfied.
• Check to see whether the contractor is properly licensed or bonded.
Call your state's licensing board for your state's specific requirements (where
• Insist on a written proposal and examine it for complete descriptions
of the work and specifications, including approximate starting and completion
dates and payment procedures.
• Check to see if the contractor is a member of any regional or national
industry associations (See back panel for a listing of such associations).
• Contact your local Better Business Bureau to check for a business report
or any complaints that have been filed on a contractor at www.bbb.org/bureaus.
• Have the contractor explain his or her project supervision and quality control
procedures. Request the name of the person who will be in charge, how many workers
will be required and the estimated completion time.
• Carefully read and understand any roofing warranty offered and watch for
provisions that would void it. The lowest bid is not always the best option.
Remember, price is only one criterion for selecting a roofing contractor. Professionalism
and quality workmanship also should weigh heavily in your decision.
More coming Soon