Glossary
Roofing comes with its own vocabulary. This glossary explains the terms Ann Arbor area homeowners hear most, so you always know what your roof needs and what you are paying for.
Roofing Basics
Pitch (Slope)
The steepness of a roof, written as a ratio of vertical rise to horizontal run. A 6:12 pitch rises 6 inches for every 12 inches across. Pitch decides which materials suit the roof and how fast water sheds.
Roofing Square
A unit of measure equal to 100 square feet of roof area. Estimates and material quantities are usually quoted in squares rather than square feet.
Decking (Sheathing)
The wood panels, usually plywood or oriented strand board, fastened to the rafters that form the structural base the roof is built on.
Underlayment
A water-resistant layer installed over the decking and beneath the shingles, adding a second line of defense against moisture.
Thin metal pieces installed at joints, edges, and around openings such as chimneys and vents to steer water away from vulnerable seams.
Eave
The lower edge of a roof that overhangs the exterior wall, where gutters are typically mounted.
Rake
The slanted edge along the end of a roof, running from the lower corner up to the peak. It is the diagonal edge you see when you look at a house from the side.
Ridge
The horizontal peak where two roof slopes meet at the top of the roof.
Valley
The internal angle where two roof slopes meet and channel water down toward the gutters.
The horizontal board running along the eave that caps the rafter ends and carries the gutters.
The underside panel beneath the eave overhang, often vented to let air into the attic.
Course
A single horizontal row of shingles or other roofing material.
Residential Roofing
The most common residential roofing material: a fiberglass mat coated in asphalt and surfaced with mineral granules.
3-Tab Shingle
A flat, single-layer asphalt shingle with cutouts that form three even tabs, giving a uniform, lower-cost finish.
Architectural Shingle (Dimensional)
A multi-layer asphalt shingle that adds depth and a textured look, with a longer rated lifespan than 3-tab.
Starter Strip
The first row of shingles set at the eaves and rakes, designed to seal and anchor the edge against wind and water.
Shingles shaped to cover the ridge line and seal the peak where two slopes meet.
Granules
The mineral coating on asphalt shingles that shields the asphalt from UV rays and adds color and fire resistance.
Drip Edge
Metal flashing along the eaves and rakes that directs runoff into the gutter and away from the fascia.
Metal Roofing
A metal roof with raised, interlocking vertical seams that hide the fasteners and shed water cleanly.
Exposed Fastener Panel
A metal roof where screws are driven through the face of the panel. A lower-cost option that needs periodic fastener checks.
Gauge
A measure of metal thickness. A lower gauge number means a thicker, stronger panel.
Snap-Lock
A standing seam profile whose panels snap together along the seam without on-site mechanical seaming.
Roof Repair
Pipe Boot
A flexible flashing collar that seals around a plumbing vent pipe where it exits the roof. A cracked boot is a frequent source of leaks.
Step Flashing
Overlapping L-shaped metal pieces installed where a slope meets a wall, layered with each course to keep the joint watertight.
Counter Flashing
A second layer of flashing set into a wall or chimney that covers the top edge of the step or base flashing.
Sealant
A weatherproof compound used to close small gaps and seal flashing, fasteners, and openings.
Leak Detection
Tracing the source of a leak, which often enters the roof far from where the stain shows up inside.
Roof Replacement & Installation
Tear-Off
Removing the existing roof down to the decking before installing a new one, which allows the deck to be inspected and repaired.
Overlay (Re-Roof)
Installing new shingles over a single existing layer instead of tearing off. It costs less up front but hides the deck and can shorten roof life.
Ice and Water Shield
A self-adhering waterproof membrane applied at eaves, valleys, and openings to guard against ice dams and wind-driven rain.
A ridge of ice that forms at the eave and traps melting snow, forcing water back up under the shingles.
Deck Repair
Replacing rotted or damaged decking found during a tear-off before the new roof is installed.
Inspection & Maintenance
Roof Inspection
A documented assessment of a roof’s condition covering the surface, flashing, openings, and drainage to catch problems early.
Preventive Maintenance
Routine upkeep such as clearing debris and resealing flashing extends a roof’s life and heads off larger repairs.
The number of years a roof system is expected to perform before it needs replacement, based on material and installation quality.
Storm Damage & Insurance
A request to a homeowner’s insurer to cover storm or sudden damage to a roof.
Adjuster
The insurance representative who inspects the damage and decides what the policy will pay.
Supplement
An added request for costs missed in the original insurance estimate, backed by documentation.
Deductible
The amount a policyholder pays out of pocket before insurance coverage applies.
Replacement Cost Value (RCV)
A claim settlement that pays the full cost to replace the roof, often released in stages as the work is completed.
Gutters & Drainage
The channel mounted along the eave that collects roof runoff and routes it to the downspouts.
Downspout
The vertical pipe that carries water from the gutter down to the ground or a drainage system.
Gutter Guard
 A cover or screen that keeps leaves and debris out of the gutter while letting water through.
Gutter Apron
A flashing that bridges the roof edge and the gutter so water can’t slip behind the gutter and rot the fascia.
Splash Block
A sloped block set under a downspout to carry water away from the foundation.
Gutter Diverter
A specialized flashing used where a sloped roof meets a vertical wall that help direct water into the trough. Can also be used in a steeply sloped valley to prevent runoff. Commonly known as kickout flashing.
Gutter Wedge
An angled shim placed between the fascia board and the back of the trough, causing the gutter to hang level and allow for proper water drainage.
Attic Ventilation
Attic Ventilation
A balanced system of intake and exhaust vents that moves air through the attic to control heat and moisture.
Box Vent
Individual exhaust vents that are placed near the ridge of the roof, letting hot air escape from the top of the attic.
Ridge Vent
An exhaust vent that runs along the ridge, letting hot air escape from the top of the attic.
Soffit Vent
An intake vent in the soffit that draws cooler outside air into the attic.
Intake & Exhaust
The two halves of attic airflow. Intake vents low at the soffit bring air in, exhaust vents high at the ridge let it out.
Skylights
A glazed unit set into the roof to bring daylight into the space below.
Curb-Mounted Skylight
A skylight installed on a raised frame, or curb, built up from the roof surface.
Deck-Mounted Skylight
A skylight fixed directly to the decking for a lower profile, sealed with a manufacturer’s flashing kit.
Flashing Kit
An intake vent in the soffit that draws cooler outside air into the attic.
Intake & Exhaust
The set of pre-formed flashing pieces matched to a skylight model that seals it to the surrounding roof.
For more in-depth information, advice, and news from your local roofing experts click here to visit our blog.
Primary Communities Served
Ann Arbor | Dexter | Chelsea | Saline | Ypsilanti | Milan | Belleville | Canton | Plymouth | Whitmore Lake | Northville | Pinckney | Brighton | Howell | South Lyon | Grass Lake | Novi |Farmington Hills | Livonia | Dearborn | Gregory | Tecumseh | Romulus | Westland | Southfield
and everywhere in between