Plain-language definitions for renovation and construction terms.
Flat, single-layer asphalt shingles with a uniform appearance; the budget option, now largely superseded by architectural shingles.
An insurance settlement basis that pays the depreciated value of the roof — you absorb the depreciation. Abbreviated ACV.
The insurance company's representative who inspects the damage and writes the claim estimate. Ohio licenses public adjusters but not company staff adjusters.
Multi-layer asphalt shingles — thicker, heavier, and longer-lasting than 3-tab; the most common residential choice today. Also called dimensional or laminate shingles.
The most common residential roofing material: a fiberglass mat coated with asphalt and surfaced with ceramic granules.
A document that signs your insurance claim rights over to a contractor; sign with caution and read the fine print. Abbreviated AOB.
The system of intake and exhaust vents that controls attic temperature and moisture, extending shingle life and helping prevent ice dams. Ohio code requires it.
A traditional flat-roof system of alternating layers of bitumen and reinforcing fabric, topped with gravel — the classic 'tar and gravel' roof. Abbreviated BUR.
A valley where shingles from one or both slopes are woven or laid across the center, hiding any metal.
The protective cap, usually metal, on top of a parapet wall that sheds water and protects the wall.
A second layer of flashing, often set into masonry, that overlaps step or base flashing to seal its top edge — common at chimneys.
A rigid board, often gypsum-based, installed over insulation on a flat roof to give the membrane a firm, durable substrate.
A small peaked structure built behind a chimney or other obstruction to divert water around it. Required for wider chimneys. Also called a saddle.
The structural wood layer — usually OSB or plywood — nailed to the rafters that the rest of the roof system attaches to. Also called sheathing.
Replacing rotten or delaminated roof sheathing found during tear-off; usually billed per sheet, typically $50 to $100 per sheet of plywood.
The amount you pay out of pocket on an insurance claim before coverage applies; in Ohio it is illegal for a contractor to 'absorb' or rebate it.
A roofed projection with a window that extends out from a sloped roof; adds valleys and flashing complexity — and cost.
A metal flashing installed along the eaves and rakes that directs water away from the fascia and into the gutter. Code-required and should never be an upcharge.
The lower edge of a roof slope, typically overhanging the wall; where gutters are mounted.
A synthetic rubber single-ply membrane (black or white) used on flat roofs; long-lasting and repairable, often ballasted or fully adhered.
A metal panel roof attached with visible screws and rubber washers; cheaper than standing seam, but the washers need periodic attention. Also called screw-down panel.
The horizontal board running along the eave behind the gutter, covering the rafter ends.
Traditional asphalt-saturated roofing underlayment, sold in 15-lb and 30-lb weights; increasingly replaced by synthetic underlayment.
The main expanse of shingles covering the roof slopes, as opposed to the starter, hip, and ridge pieces.
Thin metal pieces installed at roof joints, walls, chimneys, valleys, and penetrations to direct water away and prevent leaks.
The triangular section of wall at the end of a pitched roof, between the two roof slopes.
A steel sheet coated with an aluminum-zinc alloy, widely used for metal roofing for its corrosion resistance.
Erosion of the protective mineral surface on asphalt shingles, exposing the asphalt to UV and accelerating aging.
The mineral coating on asphalt shingles that protects the asphalt from UV; granule loss showing up in gutters is a sign of aging or hail damage.
Bruising, granule loss, or fractures in the shingle mat caused by hail; often not visible from the ground and assessed by an adjuster or roofer.
The external angle where two roof slopes meet, sloping down from the ridge to the eaves.
Pre-formed or cut shingles installed over hips and ridges to cover the seam and finish the roof.
A self-adhering waterproof membrane applied at eaves, valleys, and penetrations to block leaks from ice dams and wind-driven rain. Required by Ohio code at the eaves.
A ridge of ice that forms at a roof's edge and prevents meltwater from draining, forcing it back under the shingles. Caused by uneven roof-surface temperature.
A shingle that passes UL 2218 impact testing (Class 1 through Class 4); a Class 4 shingle may earn an insurance discount in hail-prone areas.
A channel installed at the eaves to keep attic insulation from blocking soffit-vent airflow. Also called a ventilation baffle or chute.
Coverage from the shingle or membrane maker against material defects; some enhanced 'system' warranties require certified installers and product registration.
A single-ply waterproof sheet — EPDM, TPO, or PVC — used on flat and low-slope roofs.
An asphalt-based flat-roof system reinforced with polymers, installed in rolls by torch, hot mop, or peel-and-stick. Often called mod bit.
An Ohio insurance regulation (Ohio Administrative Code 3901-1-54) that can require an insurer to pay for a reasonably uniform appearance when matching materials are not available.
A valley finished with exposed metal flashing down the center, with the shingles cut back on each side.
Oriented strand board — an engineered wood panel commonly used for roof decking; an alternative to plywood.
Installing new shingles directly over the old layer without tearing off. Ohio code allows at most two layers of shingles and prohibits it in some conditions. Also called a re-cover.
A low wall extending above the edge of a flat roof; it requires its own flashing and coping.
Anything that pierces the roof surface — vent pipes, chimneys, skylights, fans — each requiring its own flashing detail.
Local authorization to do roofing work; many Ohio jurisdictions require one for a full replacement, and a final inspection closes it out.
A flexible flashing collar that seals around plumbing vent pipes where they penetrate the roof; a common leak point when the rubber cracks.
A licensed professional you can hire to negotiate an insurance claim on your behalf, typically paid a percentage of the settlement.
A heat-welded thermoplastic flat-roof membrane known for chemical resistance and durable welded seams.
A measure of insulation's resistance to heat flow; higher is better. Relevant for attic insulation and above-deck flat-roof insulation.
The sloped edge of a gable roof, running from the eave up to the ridge.
The portion of an RCV claim held back until you complete the work and submit proof; released as the final payment.
An insurance settlement basis that pays the full cost to replace the roof, usually in two checks, with the second released after the work is completed. Abbreviated RCV.
The horizontal line at the top of a roof where two slopes meet.
A continuous vent installed along the ridge that lets hot, moist attic air escape; paired with soffit vents for balanced ventilation.
An internal drain in a flat roof that channels water through pipes inside the building.
A metal bracket fastened to the roof to support planks, used by crews working on steep pitches; the term is also used loosely for a pipe-vent flashing.
The steepness of a roof, expressed as the vertical rise in inches over 12 inches of horizontal run (e.g., 6/12). Steeper pitches cost more to roof.
Short, large-head galvanized nails used to fasten shingles; Ohio code specifies minimum length, number per shingle, and placement.
An opening in a flat roof's parapet wall that lets water drain off the edge.
The wood panels (OSB or plywood) that form the roof deck over the rafters; the substrate for underlayment and shingles.
A roof window; a known leak risk that is often replaced or re-flashed during a roof replacement.
The angle of a roof surface; another word for pitch. 'Low-slope' roofs (under about 3/12) need membrane systems rather than shingles.
The underside of a roof overhang; often vented to allow intake airflow into the attic.
Intake vents in the soffit that draw cool outside air into the attic, working with ridge or roof vents to exhaust hot air.
A unit of roof measurement equal to 100 square feet. Roofers price materials and labor by the square, not the square foot.
A metal roof system with raised, interlocking vertical seams and concealed fasteners; durable and low-maintenance but higher cost.
A specialized first row of shingles (or cut shingles) installed at the eaves to seal the bottom edge and resist wind uplift. Also called the starter course.
Individual bent metal pieces woven into the shingle courses where a roof slope meets a vertical wall.
A lightweight, tear-resistant plastic-based underlayment that outperforms felt and is now standard on quality roofing jobs.
Flat-roof insulation cut at a slight slope to create positive drainage toward the drains or scuppers.
Removing the existing roof covering down to the decking before installing a new one; the opposite of an overlay.
Thermoplastic polyolefin — a heat-welded single-ply flat-roof membrane, usually white for reflectivity; popular for energy efficiency.
A water-resistant layer (felt or synthetic) installed over the decking and beneath the shingles as a secondary moisture barrier.
The internal angle where two roof slopes meet; a high-water-flow area that needs ice-and-water shield and careful flashing.
Lifted, creased, or torn-off shingles caused by high winds; a creased shingle has a broken seal even if it lays back down.
A shingle's tested resistance to wind uplift (for example 110 or 130 mph), established by ASTM standards D3161 and D7158.
The roofer's own guarantee on installation quality, separate from the manufacturer's material warranty.
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