THE ROOFING GLOSSARY
Every term that shows up in a quote, an inspection, or an argument with a bad contractor — in plain English. Bookmark it; bring it to any bid.
The roofing unit of area: 100 square feet. A '24-square roof' is 2,400 sq ft of roof surface.
Removing all existing roofing down to the deck before installing new — the opposite of a layover.
Installing new shingles on top of old ones. Cheaper today, costly later; hides deck problems and voids many warranties.
The plywood or OSB boards the roof is built on. Rotted decking must be replaced before new shingles go down.
The water-resistant layer between deck and shingles — modern synthetic replaces old tar paper.
Self-adhering rubberized membrane at eaves and valleys that survives standing water from ice dams. Required by NY code at eaves.
Metal edging at eaves and rakes that steers water away from fascia boards.
The lower, level edge of the roof — where gutters hang and ice dams form.
The sloped side edge of a roof, from eave to ridge.
The horizontal top line of a roof where two slopes meet.
A sloped external junction where two roof planes meet — hip roofs have no gables.
The internal channel where two roof planes meet — the highest-flow, highest-risk waterway on the roof.
Metal that waterproofs transitions: chimneys, walls, valleys, penetrations. Reused flashing is a leading cause of new-roof leaks.
Individual L-shaped flashing pieces woven with shingles where a roof meets a wall.
The gasketed collar sealing plumbing vent pipes — a cheap part with an outsized share of roof leaks when it cracks.
Purpose-made first course of shingles at eaves and rakes that seals the roof edge against wind lift.
Laminated, dimensional shingles — thicker, longer-lasting, higher wind rating than flat three-tab shingles. The modern standard.
The older single-layer shingle style; cheaper, flatter, shorter-lived.
The mineral surface of a shingle — its UV sunscreen. Granules collecting in gutters signal shingle aging.
Shingle edges lifting or turning with age and heat cycling — an invitation for wind and water.
A continuous exhaust vent along the ridge line letting attic heat escape — half of a proper ventilation system.
Intake vents under the eaves feeding cool air into the attic — the other half. Blocked soffits choke the system.
A wall of refrozen meltwater at the eave that ponds water under shingles. New York's signature winter roof failure.
Standing water that fails to drain — a killer on low-slope roofs.
Roof steepness, written as rise/run: a 6/12 roof rises 6 inches per foot. Below ~2/12, shingles aren't appropriate.
A roof is bigger than the house's footprint — pitch and overhangs add area. That's why quotes measure the roof, not the floor plan.
Satellite/aircraft-based roof measurement (squares, lengths, pitch) used for accurate quotes without a tape measure.
NYC's Home Improvement Contractor license — legally required to solicit or perform residential remodeling in the five boroughs. Verify any contractor's number with the city.
Proof of a contractor's liability and workers' comp coverage. Collect it before work starts, directly from the insurer if possible.
NY's mandatory 3-business-day right to cancel a home-improvement contract signed in your home.
A written, signed amendment for mid-job additions (like extra plywood). Verbal change orders are how disputes start.
Filing your new roof with the shingle maker so the warranty exists in your name — a step forgetful contractors skip.
Rolling magnetic bar cleanup of nails from lawn and driveway on completion day — the difference between crews.
Getting the deck covered with underlayment so the house is waterproof before shingles finish — never left incomplete overnight.
The tested wind speed shingles resist (typically 110–130 mph on architectural lines) — dependent on correct nailing.