Roofing 101

Your Guide to a Strong and Reliable Roof

Understanding the world of roofing repairs and restoration is important to maintaining one of your most valuable investments–your home. With this page as your guide, you can navigate the essentials of roofing–from terminology to insurance claims–and make informed decisions about the future of your home.


Find answers to commonly asked questions about roofing and restoration.


How long does an inspection take?

The average residential roofing inspection can take anywhere from 25-45 minutes. It all depends on the size of your home and the pitch (steepness and angle) of your roof. During the inspection, we look at the condition of your shingles and every component that makes up your roofing system.

Most roof installs take just 10-12 hours, depending on the size and complexity of the roof. We are usually finished and out of your hair in one day. Our crews prioritize safety and the highest standards of quality installation, ensuring your job proceeds efficiently and effectively. At the end of the job, we strive to leave your property clean and free of debris so you can get on with your life and enjoy your new roof.

If your roof is 10 years old or more, we recommend yearly inspections to ensure all components are working as they should. If your home endures extreme weather like windstorms or hail storms, it is highly recommended you have your roof checked for damage immediately. That way, we can get on top of the shingle repair before further damage occurs.

For most homeowners, a laminated or architectural shingle is an excellent choice as it carries extended warranties, is longer-lived, and is better able to withstand severe storm damage.

Metal roofs are also a great choice, but keep in mind that they require annual maintenance to ensure the roofing system is performing as it should. We offer maintenance packages for all roofing types, so if you’re interested in this option, speak to us about what’s possible.

Architectural shingles and premium shingles can undoubtedly increase a home’s value, in some cases up to 7%. Additionally, a new roof offers fantastic curb appeal that could be the deciding factor for potential buyers.

Yes! We offer several different types of gutter systems and accessories to suit your style and budget.

So many factors affect the total roof replacement cost, so this is a tricky question to answer. We recommend meeting with one of our certified roofing specialists, who will inspect your roof and talk you through some options. We can always work with you to help you decide on a roofing system that fits your budget and style preferences.

In roofing, as with most things in life, you get what you pay for! You certainly have every right to choose the contractor you want, but if we could offer one piece of advice—be sure they are manufacturer-certified. Certification gives you access to extended warranties, meaning you have recourse if anything goes wrong.

While some contractors might promise to waive the deductible, this is above the law and, therefore, something Terminus will not offer. Waiving the deductible is a form of insurance fraud. As a homeowner, you are obligated under your policy to pay the deductible amount for your roofing claim.

Your home insurance policy covers the house as soon as the policy is activated. You can file any claim necessary as long as the policy is active. You must file a claim immediately after an active storm event. Please note that the storm damage you claim must have occurred after your policy activation date.

Not all insurance policies are the same. But in general, storm damage is considered an “ACT OF GOD,” i.e., something you could not have prevented from happening. Call your agent if you are unsure if a claim will affect your premiums.

Terminus offers certified manufacturer warranties for all roofs with options for upgraded warranties according to your preference. Upgraded warranties extend the terms and conditions of your warranty and increase the value of your roofing system. All work comes with our standard two-year guarantee, which can be extended to 10 or 15 years with a paid extended warranty.

It depends on the type of roofing system you have. An asphalt shingle roof will last 20-25 years if well-maintained.


Roofing contractors may use industry terms you’re unfamiliar with. Our roofing glossary defines common residential roofing construction terms to help you understand them.

Algae Discoloration

Roof discoloration resulting from a common algae, often mistaken as fungus growth.


The Asphalt Roofing Manufacturers Association, a trade association representing North American manufacturers of asphalt roofing materials.

ASTM International

A voluntary organization dedicated to the development of consensus standards, testing procedures, and specifications in various industries, including roofing.


Bituminous waterproofing material applied to roofing materials during manufacturing.

Asphalt Primer

Thin liquid bitumen applied to a surface to enhance adhesion of self-adhering membranes and absorb dust.

Asphalt Roof Cement

Asphalt-based cement utilized to bond roofing materials, also known as flashing cement or mastic, conforming to ASTM D4586 (asbestos free).

Architectural Shingles

Also referred to as Laminated Shingles, these are shingles containing multiple layers for added thickness.

Back Surfacing

Fine-mineral matter applied to the back side of shingles to prevent sticking together.

Base Flashing

Part of flashing attached to or resting on the deck, directing water flow onto the roof covering.

Base-ply sheet

Intended as the base or middle ply in residential self-adhering roll roofing systems.

Base Sheet

Intended to be used as a base ply in self-adhering roll roofing systems.


Bubbles appearing on asphalt roofing after installation.


Reroofing with metric-size shingles method.

Built-Up Roof

Flat or low-sloped roof with multiple layers of ply sheets embedded in hot asphalt.


Package containing shingles, typically 3, 4, or 5 bundles per square.

Butt edge

Lower edge of shingle tabs.

View Example
Cap Sheet

Mineral-surfaced material used alone or as top layer of multi-layer rolled roof covering system.


Filling a joint with mastic or asphalt cement to prevent leaks.


Refers to Asphalt Roof Cement.

Chalk Line

Roof marking made by snapping a taut, chalk-dusted string for alignment.

Class “A” Fire Resistance

Highest fire test classification for roofing, indicating resistance to severe external fire exposure.

Class “B” Fire Resistance

Classification indicating moderate resistance to external fire exposure.

Class “C” Fire Resistance

Classification indicating light resistance to external fire exposure.

Class 4 Impact Resistance

Highest impact resistance classification per UL 2218 Impact test, indicating resistance to hailstorm impacts.

Closed Cut Valley

Valley treatment method where one side’s shingles extend across the valley, while the other side’s shingles are trimmed 2” from the valley centerline.


Pre-formed flange sealing the roof around a vent pipe opening, also known as vent sleeve.

Concealed Nail Method

Roll roofing application where nails are hidden, covered by cemented, overlapping courses.


Water vapor turning into liquid on contact with a cold surface.

Counter Flashing

Flashing attached vertically to prevent water from seeping behind the base flashing.


A row of shingles or roll roofing running along the roof’s length.


Number of layers between exposed roofing surface and deck.


Peaked saddle construction behind a chimney, preventing snow accumulation and deflecting water.


Open portions of a strip shingle between tabs.


Surface installed over framing members to which roofing is applied.


Framed window unit projecting through the sloping roof.

Double Coverage

Asphalt roofing with overlapping portions at least 2” wider than exposed portion, forming two layers.


Pipe draining water from roof gutters, also known as leader.

Drip Edge

Non-staining material along eaves and rakes, directing water run-off clear of underlying construction.


Roof’s horizontal lower edge.

View Example
Eave Flashing

Extra roofing layer at eaves to prevent water damage.

Exposed Nail Method

Roll roofing application where nails are exposed to weather.


Portion of roofing exposed to weather after installation.


Fibrous material saturated with asphalt, used as underlayment.

Fiberglass Mat

Core material in asphalt shingles made from glass fibers.


Metal pieces preventing water seepage around roof intersections and projections.


Upper triangular sidewall portion meeting at the ridge of a double sloping roof.

Gable Roof

Simple two-sided roof above a gable.

Gambrel Roof

Roof with two sloping planes of different pitch on each side, with a gable at each end.


Ceramic-coated crushed rock adding color and protection to asphalt roofing.


Trough channeling water from eaves to downspouts.

Head Lap

Shortest distance from butt edge of overlapping shingle to upper edge of shingle in second course below.

Hexagonal Shingles

Shingles resembling hexagons after installation.


Inclined external angle formed where two sloping roof planes meet.

Hip Roof

Roof with sloping planes on all four sides, no gables.

Hip Shingles

Shingles covering an inclined external angle formed by two sloping roof planes.

Ice Dam

Formation at lower roof edge from thawing and refreezing of snow, forcing water under shingles.

Ice Dam Protection

Self-adhering underlayment at eaves to prevent water damage due to ice dams.

Impact Resistant Shingles

Shingles designed to withstand hail storm impacts.

Interlocking Shingles

Shingles mechanically fastening to provide wind resistance.

Laminated Shingles

Shingles with multiple layers for extra thickness, also called three-dimensional shingles.


Covering one shingle or roll with another.

Lap Cement

Asphalt-based cement adhering overlapping plies of roll roofing.

Low Slope Application

Installing shingles on roof slopes from 2” to less than 4” per foot.

Mansard Roof

Roof with two sloping planes on each side, the lower steeper than the upper, with gables at each end.

Mineral Stabilizers

Inert materials added to asphalt in shingles for durability and resistance to fire and weathering.

Mineral-Surfaced Roofing

Asphalt shingles and roll roofing covered with granules.


Re-roofing method with new shingles over old, where the new shingle’s top edge butts against the bottom edge of the existing shingle tab.

No-Cutout Shingles

Shingles with single, solid tabs, no cutouts.

Non-Veneer Panel

Wood-based panel without laminated veneer, like wafer board or oriented strand board.

Open Valley

Valley construction method where shingles on both sides are trimmed along chalk lines without extending across the valley.

Organic Felt

Asphalt roofing base material made from cellulose fibers.


Roof portion extending beyond building’s exterior walls.


Wooden platforms for storing and shipping shingle bundles.


Roofing layer (e.g., one-ply, two-ply).


Accumulation of water on roof in low-lying areas.


Asphalt-based primer preparing surfaces for bonding with self-adhering asphalt sheets.


Vertically applying shingle courses up the roof.


Supporting framing member beneath the deck, sloping from ridge to wall plate.


Inclined roof edge over a wall.

Random-Tab Shingles

Shingles with varying tab sizes and exposure.


Adding another layer of roofing over an existing one (maximum two layers allowed).

Release Tape

Plastic strip on self-sealing shingles preventing sticking in bundles.


Removing existing roof coverings and replacing with a new system.


Uppermost horizontal angle where two sloping roof planes meet.

Ridge Shingles

Shingles covering the horizontal external angle formed by sloping roof planes.


Vertical distance from eaves line to ridge.

Roll Roofing

Asphalt roofing products in roll form.

Roofing Tape

Asphalt-saturated tape for flashing and patching asphalt roofing.


Horizontal distance from eaves to point under ridge, half the span.

Saturated Felt

Asphalt-impregnated felt used between deck and roofing material.


Styrene-Butadiene-Styrene, a synthetic polymer mixed with asphalt for flexibility.

Self-Adhering Shingle Underlayment

Waterproofing underlayment protecting against water infiltration due to ice dams or wind-driven rain.

Self-Sealing Shingles

Shingles with factory-applied adhesive strips or spots.

Self-Sealing Strip or Spot

Factory-applied adhesive bonding shingle courses when exposed to sunlight heat.


Roll roofing portion overlapped by succeeding course to achieve single or double coverage at the lap.


Slight differences in shingle color due to manufacturing.


Deck supporting roofing.

Shed Roof

Roof with one sloping plane, no hips, ridges, valleys, or gables.

Single Coverage

Roofing with one layer over the deck.


Roof incline expressed as the ratio of rise to run (e.g., 4/12 has 4in rise per 12in run).

Smooth-Surfaced Roofing

Roll roofing with ground talc or mica, not granules-coated.


Finished underside of eaves.

Soil Stack

Roof-penetrating vent pipe.


Horizontal distance from eave to eave.


Roof measure unit covering 100 square feet.

Square-Tab Shingles

Shingles with tabs of the same size and exposure.

Standard Slope Application

Installing asphalt shingles on slopes of 4” to 21” per foot.

Starter Strip

Asphalt roofing at eave, providing extra protection under the first course of shingles.

Steep Slope Application

Installing asphalt shingles on slopes greater than 21” per foot.

Step Flashing

Base flashing method where a vertical surface meets a sloping roof plane.

Strip Shingles

Asphalt shingles with a single layer, three times long as wide.

Synthetic Underlayment

Polypropylene underlayment alternative to felt.


Exposed portion of strip shingles between cutouts.


Mineral applied to back of shingles to prevent sticking.

Tear Off

Removing existing roofing system down to the structural deck.


Shingle distortion when new roof is applied over uneven surface.

Three-Dimensional Shingles

See Laminated Shingles.

Top Lap

Roofing portion covered by succeeding course after installation.


Underwriters Laboratories, LLC.

Ul Label

Label indicating asphalt roofing’s fire and wind resistance level.


Asphalt-saturated felt or synthetic material under roofing for additional deck protection.


Internal angle formed by intersection of two sloping roof planes.

Vapor Retarder

Material preventing water vapor passage.


Air outlet protruding through roof deck, like a pipe or stack.

Vent Sleeve

See Collar.

Woven Valley

Valley construction with woven shingles on both sides, no exposed valley flashing.

Extensive Warranty Coverage For Your Home

At Terminus, we prioritize your peace of mind. As GAF-certified contractors, you’re in good company when you partner with us. Our highly qualified team meets GAF’s stringent requirements, including state licensing and insurance. We offer enhanced GAF warranties tailored to your project’s needs, ensuring your investment is well protected. When it comes to roofing solutions, trust Terminus for the best-in-class services.

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 Your Insurance Advocate

With extensive experience in working with major insurance agencies, our team guides you through the complex world of insurance claims. We don’t just provide premium roof repair; we’re your advocate, dedicated to helping you maximize coverage and secure the protection your home or property deserves.

  • Insurance Expertise
  • Navigating Claims
  • Maximizing Coverage

Our Winning Partnership with GAF Shingles

As the best in roofing and restoration, we proudly partner with GAF, the leading manufacturer of high-quality shingles. This is a win-win for our clients, ensuring that you receive the best materials available and can expect exceptional durability, performance, and style.

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