100 Roofing Terms Every Homeowner and Contractor Should Know

A roofing glossary is most useful when each word points to something real on the roof or in the paperwork. A square is 100 square feet of roof area. Pitch is rise over run. Flashing is the metal that keeps water out of joints. Underlayment is the layer under the shingles. Once you can connect a term to a component, a photo, or a line on an estimate, you can ask better questions and compare bids on equal footing.

Below are 100 roofing terms, grouped the way a roof is actually built and inspected: shape and measurement, structure and deck, underlayment and flashing, coverings and materials, ventilation and moisture, install and workmanship, slope and codes, then storm and insurance language. Definitions are plain and accurate, with short usage notes on what each term affects in a real project. Where a term has a technical definition, it follows the way industry sources such as the NRCA, ARMA, InterNACHI, and the model building codes describe it.

This is written for two readers at once. A homeowner reading an estimate wants to know what "drip edge," "ice-and-water," and "recoverable depreciation" mean before signing. A contractor's office, sales, and production teams want everyone using the same word for the same part so a job does not get described three different ways across a quote, an install note, and an invoice. Consistent vocabulary is also why contractors who keep tidy roof records, including those who use tools like RoofPredict, can hand a job from sales to crew to service without losing the thread.

One caution before the list: a glossary helps you talk about a roof, not design one. Real roof assemblies depend on material, slope, deck condition, climate, code, and manufacturer instructions. When a term changes the scope, price, warranty, or code compliance of a job, ask the contractor to show where it appears in the written estimate.

The fastest terms to learn first

If you only have time to learn a handful before reading an estimate, learn these. Each one is a place where two bids quietly differ or where a misunderstanding costs money.

Term	Plain meaning	Why it matters on your estimate
Square	100 sq ft of roof area	How roofers price and quantify the job
Slope (pitch)	Steepness as rise:run, e.g. 6:12	Drives material choice and labor cost
Decking	The plywood/OSB under the roof	Hidden rot here becomes a change order
Underlayment	Layer under the shingles	Felt vs. synthetic vs. ice-and-water differ a lot
Flashing	Metal that seals joints and edges	Where most leaks start; often vaguely scoped
Ventilation	Attic airflow, intake plus exhaust	Affects shingle life and condensation
Scope of work	Written list of what is and isn't done	The document that makes two bids comparable
ACV / RCV	Depreciated vs. full replacement value	Determines what your insurer pays
Deductible	Your out-of-pocket share	The homeowner's to pay; never waive it

Roof Shape and Measurement Terms

These are the words that describe the geometry of a roof and how it is measured. They show up in the first paragraph of almost every estimate.

1. Square. A roofing unit of area equal to 100 square feet. Roofers price and order material by the square, not the bundle. A 2,000-square-foot roof surface is 20 squares, before waste.

2. Pitch. The steepness of a roof expressed as a ratio of vertical rise to horizontal run, written as rise-over-run such as 6:12 (six inches of rise for every twelve inches of run). Strictly, pitch historically meant rise over the full span, but in everyday roofing it is used interchangeably with slope.

3. Slope. Roof steepness expressed as inches of rise per 12 inches of run, such as 4/12. Slope drives nearly every material decision, because low-slope and steep-slope roofs shed water differently and call for different products. The common dividing line is around 2:12 to 4:12.

4. Rise. The vertical distance a roof gains over a measured horizontal run. The "6" in a 6:12 roof.

5. Run. The horizontal distance used to measure slope, always expressed as 12 in the rise-over-run ratio. The "12" in 6:12.

6. Roof plane. One continuous flat or curved surface of a roof. A simple gable roof has two planes; a complex roof can have a dozen, and each plane edge is a place water has to be managed.

7. Ridge. The horizontal line at the top of a roof where two sloping planes meet. The highest edge of the roof and the usual location for exhaust ventilation.

8. Hip. The external sloping line where two roof planes meet and angle downward, on a roof with no gable end. Hips shed water outward and need their own cap shingles.

9. Valley. The internal angle where two roof planes meet and channel water downward. Valleys carry concentrated water flow and are a frequent leak location if poorly detailed.

10. Eave. The lower, horizontal edge of a roof, often overhanging the exterior wall. Eaves are where ice dams and wind-driven rain attack, which is why ice-and-water membrane is often specified here.

11. Rake. The sloped, inclined edge of a gable roof, running from eave to ridge. The rake is the edge you see from the side of a gable.

12. Gable. The triangular section of exterior wall formed under the end of a pitched roof. A "gable roof" is the classic two-plane shape that meets at a ridge.

13. Hip roof. A roof that slopes downward on all sides with no vertical gable end. Hip roofs tend to perform better in high wind because they present no flat gable wall to catch it.

14. Dormer. A framed structure that projects out from a sloping roof plane, usually containing a window. Every dormer adds sidewall and headwall flashing, so dormers raise both cost and leak risk.

15. Mansard. A roof with two slopes on each side, a steep lower slope and a shallow upper slope, creating usable attic space. Common on commercial and French-influenced buildings.

16. Gambrel. A two-slope roof like a barn roof, steep on the bottom and shallow on top, but on the gable ends rather than all four sides as a mansard does.

17. Overhang. The portion of a roof that extends beyond the exterior wall, including the eave and rake projections. Overhangs shade walls and shed water away from the foundation.

18. Low-slope roof. A roof with a pitch typically below 2:12 to 3:12 that cannot rely on fast runoff and instead needs a water-resistant membrane system. Often loosely called "flat," though almost no roof is truly flat.

19. Steep-slope roof. A roof with enough pitch (generally 3:12 and above) that water sheds quickly and shingles, shakes, tile, or metal panels are appropriate. Steep slopes shed water well but raise fall hazards for crews.

20. Field. The main, open area of a roof plane, away from edges, ridges, valleys, and penetrations. "Field shingles" are the standard shingles covering the bulk of the roof.

Structure and Deck Terms

These terms describe what is under the roof covering. They matter most when a tear-off reveals hidden damage and the estimate has to account for unknowns.

21. Decking (sheathing). The structural surface, usually plywood or oriented strand board (OSB), fastened to the framing that supports the roof covering. Decking and sheathing are used interchangeably. Older homes may have solid-board or plank decking.

22. Rafter. A sloped framing member running from ridge to eave that supports the deck. Stick-framed roofs use rafters; many newer homes use trusses instead.

23. Truss. An engineered, triangulated framing assembly that carries roof loads to the walls. Trusses are designed as a unit and should never be cut or modified without an engineer.

24. Ceiling joist / collar tie. Horizontal framing members that tie rafters together and resist the outward thrust of the roof. A collar tie sits higher up the rafter span.

25. Ridge board / ridge beam. The member at the peak that rafters fasten to. A ridge beam is structural and load-bearing; a ridge board is a nailer in a rafter-tie system.

26. Fascia. The vertical board or trim along the eave and rake edges, often where the gutter mounts. Fascia rot is a common sign of long-term edge leakage.

27. Soffit. The finished underside of an eave or overhang. Vented soffit is the most common location for ventilation intake.

28. Frieze board. Trim that runs along the top of an exterior wall, tucked under the soffit where wall meets roof.

29. Substrate. The surface a roofing material is applied to, whether that is the deck, an existing roof, or a layer of insulation on a low-slope system.

30. Plank deck. Older decking made of individual boards rather than sheet goods. Gaps between planks can affect fastener holding and underlayment selection.

31. Rot. Wood decay caused by sustained moisture and fungal activity. Rotted deck or fascia generally must be replaced before new covering goes on, and is a common hidden-condition cost.

32. Delamination. Separation of the bonded layers in plywood or OSB, usually from moisture. Delaminated deck does not hold fasteners reliably.

33. Deflection. Bending or sagging of a structural member under load. Visible roof-deck deflection between rafters can signal undersized or water-damaged sheathing.

34. Load path. The route forces such as gravity, wind uplift, and snow travel through the roof and into the walls and foundation. Storm-resistant construction is largely about keeping the load path continuous.

35. Roof-to-wall connection. The structural tie where roof framing transfers force into the wall, often reinforced with hurricane clips or straps in high-wind regions.

Underlayment and Flashing Terms

Leaks rarely start in the open field. They start at edges, joints, and penetrations, which is why this is the part of an estimate worth reading slowly. The NRCA treats underlayment as a secondary weather barrier, not a primary one.

36. Underlayment. A water-shedding layer installed over the deck before the primary covering. It provides temporary weather protection during install, a secondary barrier if water gets past the covering, and a separation layer. Traditionally 15- or 30-pound asphalt felt; today often a synthetic.

37. Felt. Traditional asphalt-saturated organic or fiberglass underlayment, sold as 15-pound or 30-pound (a reference to historical weight per square). Still widely used and code-recognized.

38. Synthetic underlayment. A woven or spunbond polymer underlayment that is lighter, stronger, and more tear- and UV-resistant than felt. Now the default on many shingle jobs.

39. Ice-and-water membrane (ice barrier). A self-adhering, rubberized-asphalt underlayment that seals around fasteners and bonds to the deck. Required by code at eaves in cold climates to resist ice dams, and commonly added in valleys, around penetrations, and at low-slope transitions.

40. Ice dam. A ridge of ice that forms at a cold eave when heat from the attic melts snow higher up, the meltwater refreezes at the edge, and water then backs up under the shingles. The reason ice barrier and good attic ventilation matter in snow country.

41. Drip edge. L-shaped metal flashing installed at eaves and rakes to direct water off the deck and into the gutter, and to protect the deck edge and fascia. Code-required at edges in most jurisdictions.

42. Flashing. Metal or other material installed to direct water away from joints, transitions, and penetrations. The single most important leak-prevention detail on most roofs.

43. Step flashing. Individual L-shaped metal pieces interwoven, one per shingle course, where a roof plane meets a vertical sidewall. Properly woven step flashing is far more reliable than a bead of caulk.

44. Counterflashing. A second layer of flashing set into or attached above the base or step flashing and bent down over it, so water cannot get behind the upper edge. Often tucked into a masonry reglet on chimneys.

45. Reglet. A groove cut into masonry or concrete to receive and anchor the top edge of counterflashing. A cleanly cut reglet is a sign of careful chimney work.

46. Base flashing. The lower flashing component at a wall or curb that turns up the vertical surface; counterflashing then covers its top edge.

47. Apron flashing (headwall flashing). Flashing at the downslope side of a vertical feature, such as where a roof slope dies into a wall or the front of a chimney, diverting water out onto the roof.

48. Kickout flashing. A specialized piece at the bottom of a roof-to-wall intersection that "kicks" water out of the wall path and into the gutter. A missing kickout is a classic cause of hidden wall rot.

49. Valley flashing. Metal or membrane lining a valley to carry concentrated water flow. Open valleys show exposed metal; closed or woven valleys run shingles across. Code typically calls for valley metal to extend a set distance each way from the centerline.

50. Cricket (saddle). A small peaked structure built behind a chimney or other wide obstruction to split and divert water around it. Generally required behind chimneys above a certain width.

51. Penetration. Anything that passes through the roof plane: vent pipes, chimneys, skylights, exhaust ducts, and the like. Every penetration is a deliberate hole that has to be flashed.

52. Pipe boot. A flashing collar, often with a rubber or lead gasket, that seals around a plumbing vent pipe. Cracked rubber boots are one of the most common roof leaks, often failing before the shingles do.

53. Curb. A raised frame around a rooftop unit, skylight, or large penetration that the flashing terminates against, keeping water out at a higher elevation.

54. Sealant. A caulk or mastic used to seal small gaps. Useful as a supplement, never a substitute for correct flashing. "Sealed it" is not the same as "flashed it."

55. Backwater lap. An overlap installed facing the wrong direction, against the flow of water, which lets water work underneath. A reverse lap is an install defect.

Flashing by location: a quick map

Flashing terms confuse people because the same job uses different pieces in different spots. This table pairs each location with the flashing that belongs there, so you can check an estimate against the roof.

Location on the roof	Flashing that belongs there	Common failure if missing or wrong
Roof edge (eave/rake)	Drip edge	Water wicks behind fascia; deck-edge rot
Roof plane meets sidewall	Step flashing (woven per course)	Wall and sheathing rot behind siding
Bottom of a roof-to-wall run	Kickout flashing	Concentrated water dumped into the wall
Top/front of a chimney	Apron (headwall) flashing + cricket	Water ponds behind chimney and leaks
Top edge of base flashing	Counterflashing into a reglet	Water gets behind the base flashing
Plumbing vent pipe	Pipe boot	Cracked rubber gasket leaks within years
Valley	Valley metal or membrane	Concentrated flow erodes and leaks

A practical rule: if an estimate says "flashing as needed" with no locations named, ask the contractor to walk the roof and list which of the rows above are being replaced, reused, or excluded. Vague flashing language is the most common reason a "new roof" still leaks at a wall or chimney.

Roof Covering and Material Terms

This is where product names get thrown around. A name alone ("architectural shingles," "metal roof") does not describe a system; the accessories and details do.

56. Asphalt shingle. The most common steep-slope covering in North America, made of a fiberglass mat saturated with asphalt and surfaced with mineral granules. Governed by standards such as ASTM D3462.

57. Three-tab shingle. A flat, single-layer asphalt shingle with evenly spaced cutouts forming three tabs, giving a uniform look. The economical, thinner option, increasingly replaced by laminated shingles.

58. Architectural (laminated / dimensional) shingle. A multi-layer asphalt shingle with a textured, dimensional appearance and generally better wind and aging performance than three-tab. The most common residential choice today.

59. Fiberglass mat. The reinforcing base layer inside a modern asphalt shingle. The mat's integrity is what hail inspectors look at when judging whether an impact actually fractured the shingle.

60. Granules. Ceramic-coated mineral particles bonded to the shingle surface that shield the asphalt from ultraviolet light and add fire and color performance. Granule loss in gutters can indicate age, hail, or blistering.

61. Starter strip (starter course). A purpose-made or trimmed shingle installed first along the eaves and rakes, with its adhesive positioned to seal the first visible course and resist wind uplift at the edge.

62. Ridge cap. Shingles or accessories made or cut to cover the ridge and hips, bending over the peak. Pre-formed ridge cap is thicker and more wind-resistant than field shingles bent over a ridge.

63. Hip and ridge. The accessory category covering both hip lines and the ridge line; often sold matched to a shingle line and required for the manufacturer's wind warranty.

64. Self-seal strip. The factory line of thermal adhesive on shingles that bonds courses together once warmed by the sun, the mechanism that resists wind. Shingles installed in cold weather may need hand-sealing.

65. Metal panel roof. A covering of formed steel, aluminum, copper, or zinc panels. Includes exposed-fastener (through-fastened) and concealed-fastener systems.

66. Standing seam. A concealed-fastener metal system where panels join at raised vertical seams above the water line, allowing the metal to expand and contract. The premium long-life metal option.

67. Tile roof. Clay or concrete tile, common in hot and coastal regions, very long-lived but heavy enough that the structure must be rated for the load.

68. Slate roof. Natural stone roofing with a service life that can exceed a century. Expensive, heavy, and requiring specialized installers.

69. Wood shake / wood shingle. Split (shake) or sawn (shingle) wood roofing, usually cedar. Restricted or prohibited in many wildfire-prone areas without a fire treatment.

70. Modified bitumen. An asphalt-based low-slope membrane reinforced with polymers (APP or SBS), applied in rolls by torch, hot asphalt, cold adhesive, or self-adhesion.

71. Single-ply membrane. A low-slope covering installed in large sheets, most commonly TPO, EPDM, or PVC, mechanically fastened, adhered, or ballasted.

72. TPO / EPDM / PVC. The three main single-ply chemistries: TPO (thermoplastic polyolefin, usually white and heat-welded), EPDM (synthetic rubber, often black, seamed with tape or adhesive), and PVC (heat-welded, chemical-resistant).

73. Built-up roof (BUR). A traditional low-slope system of multiple plies of felt and bitumen topped with gravel or a cap sheet. The original "tar and gravel" roof.

74. Coating. A fluid-applied product (acrylic, silicone, or similar) used to restore or protect certain low-slope roofs, add reflectivity, or extend service life when the substrate is sound and the manufacturer permits it.

75. Impact-resistant (IR) shingle. A shingle tested to UL 2218 Class 1 through 4 for resistance to a dropped steel ball simulating hail, with Class 4 the highest. IBHS also publishes real-hail Impact-Resistant Shingle Performance Ratings used in its FORTIFIED hail supplement. Many insurers offer a premium credit for IR shingles.

Covering types compared

The major roof coverings differ in slope range, weight, and typical service life. The life ranges below are general industry expectations under normal conditions, not warranties, and any given roof can fall outside them depending on install quality, ventilation, and climate.

Covering	Typical slope	Relative weight	General service-life range
Three-tab asphalt shingle	Steep (3:12+)	Light	Around 15 to 20 years
Architectural asphalt shingle	Steep (3:12+)	Light to medium	Around 20 to 30 years
Standing-seam metal	Low to steep	Light to medium	40 to 70 years
Concrete or clay tile	Steep (often 4:12+)	Heavy	50+ years
Natural slate	Steep	Very heavy	75 to 100+ years
TPO/EPDM/PVC single-ply	Low slope	Light	20 to 30 years
Modified bitumen	Low slope	Medium	15 to 25 years

Two notes on reading this table. First, weight matters because heavy coverings such as tile and slate require a structure rated to carry them; you cannot simply swap shingles for slate without an engineer's review. Second, service life is a planning range, not a countdown to a fixed date. The same architectural shingle can last 18 years on a hot, poorly ventilated roof and 30 on a cool, well-ventilated one. That uncertainty is exactly why a documented age range, rather than a guessed exact age, is the honest way to talk about when a roof is due, and why contractors who keep age ranges on file with tools like RoofPredict can prioritize the homes most likely worn out instead of guessing.

Ventilation, Insulation, and Moisture Terms

Leaks, condensation, attic heat, and mold can look like one problem to a homeowner but are several. DOE and EPA resources draw the lines between them.

76. Attic ventilation. The movement of outside air through the attic to remove heat and moisture, normally with low intake and high exhaust working together.

77. Net free area (NFA). The measured open area of a vent through which air can actually pass, after subtracting the screen and louver material. Vents are rated in square inches of NFA, which is how ventilation gets calculated against code.

78. 1/150 and 1/300 rule. The model-code requirement (see IRC R806.2) that attic vent NFA equal at least 1/150 of the vented attic floor area, reducible to 1/300 when a vapor retarder is present in certain climates and 40 to 50 percent of the venting is high in the attic. A 1,500-square-foot attic at 1/150 needs 10 square feet of NFA.

79. Balanced ventilation. Splitting the required NFA roughly 50/50 between intake (low) and exhaust (high) so air flows steadily. Too much exhaust without intake can pull conditioned air or rain into the attic.

80. Intake vent. A vent that admits outside air low on the roof, usually at the soffit or eave. Without adequate intake, ridge exhaust cannot work.

81. Exhaust vent. A vent that lets attic air escape high on the roof, at or near the ridge.

82. Ridge vent. A continuous exhaust vent running along the ridge under a cap, the most common modern exhaust method. Should be paired with soffit intake.

83. Soffit vent. Intake venting in the soffit, either continuous strip or individual vents. The most common intake type.

84. Gable vent. A louvered vent in the gable wall. Can serve as intake or exhaust but may short-circuit a ridge-and-soffit system if mixed carelessly.

85. Static vent (box vent / turtle vent). A low-profile non-powered exhaust vent set into the roof plane, used where a continuous ridge vent is impractical.

86. Baffle (rafter vent / insulation baffle). A channel installed at the eave to keep insulation from blocking the soffit intake and preserve airflow up the rafter bay.

87. Insulation. Material that slows heat transfer through the building enclosure, rated by R-value. Roof and attic insulation interacts with ventilation, so changing one can affect the other.

88. Air sealing. Closing gaps and penetrations between conditioned living space and the attic to stop air and moisture movement. Often more effective than adding venting for condensation problems.

89. Vapor retarder. A material that slows water-vapor diffusion through an assembly, used in specific climate zones and a condition for the 1/300 ventilation ratio.

90. Condensation. Liquid water that forms when humid air meets a surface cold enough to drop it below the dew point. Attic condensation can mimic a roof leak without any breach in the covering.

91. Hot roof (unvented assembly). A roof insulated at the deck plane with no ventilated attic space, allowed where specifically designed (typically with closed-cell foam at the deck) to control condensation. Not a default; it must be engineered.

Install, Workmanship, and Documentation Terms

These describe how the roof is put on and how the job is recorded. They are where two bids that quote the same shingle can diverge in quality.

92. Tear-off (vs. overlay). Tear-off means stripping the old roofing down to the deck before installing new. An overlay (re-roof over existing) leaves the old layer in place; code generally limits a roof to two total layers and bars overlays over certain conditions.

93. Course. One horizontal row of shingles, tiles, or other covering across the roof.

94. Exposure. The portion of each shingle course left exposed to weather, not covered by the course above. Standard three-tab exposure is 5 inches. Wrong exposure voids coverage and changes how many shingles a roof needs.

95. Offset (stagger). The horizontal shift between joints in successive shingle courses, set by the manufacturer so seams do not line up and channel water. Improper offset is a workmanship defect.

96. Nailing zone (nail line). The narrow band marked on a shingle where fasteners must land. Nails placed high (above the line) or low ("shiners") are a leading cause of wind blow-off and warranty denials.

97. Fastener pull-through / overdriven nail. A nail driven too deep, cutting into the mat, or one that pulls through under load. Both compromise holding power and are common install errors found in storm inspections.

98. Dead valley. A low-slope or near-flat valley where two planes meet at a shallow angle and water drains slowly, a chronic problem area usually needing membrane rather than shingles.

99. Scope of work. The written description of exactly what the contractor will and will not do, including materials, accessories, and labor. The document that matters most when comparing bids.

100. Exclusion. Work or material specifically left out of an estimate or contract, such as decking replacement priced separately. Read exclusions as carefully as inclusions.

101. Change order. A written, signed change to the agreed scope, price, or schedule, typically used when tear-off uncovers hidden rot or decking damage.

102. Warranty (manufacturer vs. workmanship). Two different promises. The manufacturer's warranty covers the product (and is conditional on correct installation and accessories); the contractor's workmanship warranty covers labor. Both have terms worth reading.

103. Permit and final inspection. Local authorization required before many roofing jobs and the closeout review confirming the work met code. Skipping a required permit can complicate resale and insurance.

104. Roof record. A property-level file holding roof age, materials, photos, inspection notes, warranties, and service history. Keeping one is the difference between guessing a roof's age and knowing the range, which is exactly what platforms like RoofPredict help contractors maintain across thousands of homes.

Slope, Code, and Performance Terms

These terms connect a roof to the rules and ratings that govern it.

Fire rating (Class A, B, C). A roof covering's resistance to external fire exposure, tested under ASTM E108 / UL 790, with Class A the highest. Most asphalt shingles achieve Class A as a system.

ASTM D3161 and D7158 (wind classes). The two wind-resistance test methods for shingles. D3161 (fan-induced) classifies shingles Class A, D, or F; D7158 (uplift) classifies them Class D, G, or H. A D7158 Class H or D3161 Class F shingle is accepted for the highest code wind speeds, while Class G or D covers up to roughly 100 to 110 mph basic wind speed, per the model code.

Basic wind speed (V-ult). The design wind speed for a location set by code and ASCE 7 wind maps, which determines the shingle wind class and fastening a roof must meet. Higher in coastal and hurricane zones.

Wind uplift. The suction force wind exerts on a roof as it flows over the building, trying to peel covering and deck upward. The force that wind classes and FORTIFIED nailing patterns are designed to resist.

Sealed roof deck. A deck detailed to resist water intrusion if the covering blows off, typically with taped seams plus a full-coverage underlayment or self-adhered membrane. A core requirement of the IBHS FORTIFIED program.

FORTIFIED Roof. A voluntary IBHS construction standard (updated in its 2025 edition) for stronger roofs in high-wind and hail regions, built around sealed roof decks, enhanced edge attachment, and tested vents. Some insurers offer premium credits for a FORTIFIED designation.

UL 2218 (impact rating). The test that drops a steel ball on a shingle to rate impact resistance Class 1 to 4, with Class 4 the toughest. The basis for many insurer hail discounts.

Square footage vs. squares. Roof area is measured in square feet, then converted to squares (divide by 100) for ordering. Pitch increases actual surface area beyond the building footprint, which is why a steeper roof has more squares than its floor plan suggests.

Roof complexity (cut-up roof). A measure of how many planes, valleys, hips, and penetrations a roof has. A "cut-up" roof costs more per square because of added waste, flashing, and labor.

Storm and Insurance Terms

Storm and claims vocabulary is where homeowners get the most confused and where careless language can cross legal lines. A roofer documents conditions and provides an estimate. The insurer decides coverage. Keep that boundary in mind for every term below. The plain-language definitions here lean on insurer and consumer-education sources rather than sales sites.

Hail. Layered balls of ice formed in thunderstorm updrafts, logged by size in inches by the NWS Storm Prediction Center. Roughly 1-inch (quarter-size) hail is the common threshold where roof damage becomes likely, though impact angle, hardness, and roof age all matter.

Mat bruising. A soft, fractured spot in a shingle where a hailstone cracked the fiberglass mat beneath the surface, often felt before it is seen. Distinct from cosmetic granule scuffing, and the kind of damage inspectors document for a hail claim.

Granule loss. Erosion of the protective granules exposing the asphalt. Can come from hail, age, foot traffic, or blistering, so the cause matters when documenting a claim.

Blistering. Small raised bubbles in a shingle caused by trapped moisture or gases during manufacturing or from a hot, poorly ventilated attic, not from impact. It is frequently mistaken for hail and is generally not a storm claim.

Wind blow-off / creased shingle. Shingles lifted, torn, or folded by wind. A crease across a shingle that has been bent back is a documented form of wind damage.

Storm date (date of loss). The specific date a damaging storm occurred, which a claim is tied to. Homeowners can corroborate it against NOAA NCEI Storm Events records for their area.

Inspection / documentation. Photographing and noting roof conditions, measurements, and an age range to support a homeowner's own claim. A roofer documents and estimates; describing facts is legitimate, deciding coverage is not.

Actual cash value (ACV). The depreciated value of the roof, that is, replacement cost minus depreciation for age and wear. An ACV settlement is what an insurer pays before any depreciation is recovered.

Replacement cost value (RCV). The cost to replace the roof with materials of like kind and quality, without a deduction for depreciation. An RCV policy can ultimately pay the full replacement cost, subject to the deductible.

Depreciation. The reduction an insurer applies for the roof's age and condition, often by dividing current age by expected life. The difference between RCV and ACV.

Recoverable depreciation. On an RCV policy, the held-back depreciation amount the insurer releases after the work is completed and documented, on top of the first ACV check. Non-recoverable depreciation is never paid out. This is well explained in plain terms by consumer guides, but the rule of thumb is that the held-back portion is only paid when the work is actually done.

Deductible. The amount the homeowner is responsible for paying out of pocket on a claim, subtracted from the settlement. The deductible is the homeowner's to pay. Offering to waive, absorb, rebate, or "eat" a deductible is insurance fraud in many states and should be refused if a contractor proposes it.

Xactimate. The estimating software (owned by Verisk) that most carriers use to price roof claims, with regional pricing and depreciation tables built in. Many contractors estimate in the same system to speak the carrier's language.

Matching. Whether undamaged roof sections must be replaced to match repaired areas when an exact match is unavailable. Matching rules vary by state and policy, so it is a coverage question for the insurer, not a guarantee a roofer can make.

Supplement. An additional, documented request to the insurer for costs missed in the original estimate, such as extra decking or code-required upgrades found during the job. It is a documentation process, not a negotiation a roofer conducts on the homeowner's behalf.

Public adjuster. A licensed professional a homeowner may hire to represent them in a claim. A roofer is not a public adjuster, and a roofer who offers to handle, manage, negotiate, fight, maximize, or settle your claim, or to get it approved, may be engaging in unlicensed public adjusting, which is illegal in states such as Texas. Safe roofer language is "we document the conditions and provide an estimate; your insurer decides coverage."

Insurance money terms at a glance

The four terms that decide who pays what on a storm claim are easy to mix up. This table keeps them straight.

Term	What it means	Who it affects
RCV	Full replacement cost, no depreciation deducted	The ceiling of what an RCV policy can pay
ACV	Replacement cost minus depreciation for age/wear	The first check on an RCV policy; the only payment on an ACV policy
Depreciation	The amount subtracted for the roof's age and condition	The gap between RCV and ACV
Recoverable depreciation	Held-back depreciation released after work is done and documented	Paid to the homeowner only on an RCV policy, only after completion
Deductible	The homeowner's out-of-pocket share	The homeowner pays it; it is never legally waivable by the roofer

Say this, not that: safe storm-claim language

For homeowners and honest contractors, the line between legitimate documentation and illegal claims handling comes down to phrasing. The left column can cross into unlicensed public adjusting or fraud; the right column keeps you on the safe side.

DON'T SAY (risky / illegal in many states):
  - "We'll handle / manage / fight your insurance claim."
  - "We'll get your claim approved."
  - "We'll recover every dollar / maximize your claim."
  - "We'll waive / cover / eat your deductible."
  - "We're insurance claim specialists."

SAY INSTEAD (honest documentation):
  - "We'll document the roof's conditions with dated photos and
     measurements and provide a written estimate."
  - "We can give you an estimated roof-age range to include with
     your claim."
  - "Your insurer decides what is covered; you file the claim."
  - "The deductible is yours to pay under your policy."
  - "If you want representation, you can hire a licensed public
     adjuster."

How to Use These Terms in a Real Project

The value of a roofing glossary is not memorization. It is the ability to take any word in a proposal and ask three questions: where is this on my roof, is it included in the written scope, and what decision does it affect. That turns a vague conversation into a specific one.

For homeowners comparing bids, the trap is assuming two estimates that both say "architectural shingles" are the same job. One might spell out synthetic underlayment, ice-and-water at the eaves and valleys, new drip edge, starter strip, matched ridge cap, new pipe boots, step flashing replacement, and a decking allowance. The other might say "shingles and labor." Neither price means anything until you map it to terms. Use the vocabulary above to ask what each bid includes at the eave, the valley, the wall, and the penetrations, and to ask how unknown decking will be handled.

For contractors, shared vocabulary is an operations issue. When sales calls an edge board "trim," production calls it "fascia," and the invoice says "wood repair," the same item gets described three ways and disputes follow. Picking the most common 40 or 50 terms, defining them once, and requiring the team to use them in every estimate, install note, and service ticket removes a whole category of confusion. The same discipline applies to the roof record itself. A property file that captures roof age range, materials, photos, and storm history in consistent language is what lets a company prioritize follow-up, re-engage an old customer list, and skip brand-new roofs instead of knocking every door. That recordkeeping is the core of what contractors do with RoofPredict, which pairs an estimated roof-age range with storm history to flag which homes are actually due for attention, before anyone climbs a ladder.

For storm and insurance conversations specifically, the safest habit is to keep the language descriptive. Document the date of loss, the visible conditions, the measurements, and an age range. Let the homeowner file their own claim and let the insurer decide coverage. The moment a contractor starts promising to "get the claim approved," "recover every dollar," "handle the insurance company," or "cover your deductible," the conversation has left honest documentation and entered territory that is illegal in many places. Knowing the right words also means knowing which words a trustworthy roofer will never say.

A copy-ready checklist for reading any roofing estimate

Keep this next to the bids. Each line is a term from above turned into a question. If a contractor cannot answer plainly, that is useful information too.

ESTIMATE REVIEW CHECKLIST

Measurement & scope
[ ] How many squares, and is that surface area or footprint?
[ ] Is it a full tear-off or an overlay? How many layers exist now?
[ ] What is the written scope of work, line by line?
[ ] What exclusions are listed (decking, gutters, permits)?

The deck & hidden conditions
[ ] How will rotted or delaminated decking be found and priced?
[ ] What is the per-sheet decking cost in a change order?

Water control
[ ] Underlayment: felt, synthetic, or both? Where?
[ ] Ice-and-water membrane at eaves and valleys? (Required in
    cold climates.)
[ ] New drip edge at eaves and rakes?
[ ] Which flashings are NEW vs. reused: step, kickout, apron,
    counterflashing, valley, pipe boots?
[ ] Is a chimney cricket included if the chimney is wide?

Covering & accessories
[ ] Exact shingle line and wind/impact class?
[ ] Starter strip and matched hip-and-ridge cap included?
[ ] Correct nailing (per manufacturer) and cold-weather sealing?

Ventilation
[ ] Does intake (soffit) balance the exhaust (ridge)?
[ ] Does the result meet the 1/150 or 1/300 code ratio?

Paperwork
[ ] Permit pulled and final inspection included?
[ ] Manufacturer warranty AND workmanship warranty in writing?
[ ] Cleanup, magnet sweep, and debris haul-off specified?

Run the same checklist against two bids and the cheaper number often turns out to be the smaller scope, not the better deal. The vocabulary is what lets you see that.

A roof is a system, and its vocabulary is the map. The deck supports the underlayment, the underlayment backs up the covering, the flashing protects the joints, the ventilation protects the deck and the covering from the inside, and the codes and ratings tell you how much wind, fire, and hail the assembly is built to take. Learn the words for each layer and the rest of the conversation, from a $400 pipe-boot repair to a full insurance replacement, gets a great deal clearer.

Sources checked: June 18, 2026.

FAQ

What is the difference between roof pitch and roof slope?

In everyday roofing they are used interchangeably to describe steepness, and both are written as rise over run, such as 6:12, meaning six inches of vertical rise for every twelve inches of horizontal run. Strictly, slope is rise per 12 inches of run, while pitch historically meant rise over the full span of the roof. When a contractor quotes a roof, the rise-over-run number is what drives material choice, because low-slope and steep-slope roofs need different systems.

What is a roofing square and why do roofers use it?

A roofing square equals 100 square feet of roof surface area. Roofers measure, price, and order materials by the square rather than by the bundle, because the number of bundles needed per square changes from one product to another. A 2,000-square-foot roof surface is 20 squares before waste. Because steeper roofs have more surface area than their floor footprint, a roof's square count is usually larger than the home's square footage suggests.

What roofing terms should a homeowner learn before signing an estimate?

Start with square, slope, decking, underlayment, ice-and-water membrane, drip edge, flashing, step flashing, pipe boot, starter strip, ridge cap, ventilation, scope of work, exclusion, and warranty. Those words appear in almost every bid and are where two estimates quietly differ. For storm work, also learn ACV, RCV, depreciation, recoverable depreciation, and deductible, so you understand what the insurer pays, what you pay, and when held-back money is released.

What is the difference between ACV and RCV on a roof insurance claim?

Actual cash value (ACV) is the depreciated value of the roof: replacement cost minus a deduction for age and wear. Replacement cost value (RCV) is the cost to replace the roof with materials of like kind and quality with no depreciation deduction. On an RCV policy the insurer typically pays the ACV first, then releases the held-back depreciation after the work is completed and documented. The insurer, not the contractor, determines what is covered.

What is recoverable depreciation and how do I get it?

Recoverable depreciation is the amount an RCV policy holds back from the first check to account for the roof's age, and then pays out after you complete the repairs and submit proof of completion. It equals the gap between the replacement cost and the actual cash value. Non-recoverable depreciation is never paid. You generally collect recoverable depreciation only by actually doing the work and documenting it for the carrier; pocketing the first check and skipping the work forfeits it.

Can a roofing contractor handle my insurance claim or waive my deductible?

No. A contractor can document roof conditions, take photos and measurements, provide an age range, and write an estimate that supports your own claim, but the insurer decides coverage. A roofer who offers to handle, manage, negotiate, fight, maximize, or settle your claim, or to get it approved, may be practicing unlicensed public adjusting, which is illegal in states such as Texas. Waiving, rebating, or absorbing your deductible is insurance fraud in many states and should be refused.

How much attic ventilation does a roof need by code?

The model residential code (IRC R806.2) requires net free vent area of at least 1/150 of the vented attic floor area, which can be reduced to 1/300 when a vapor retarder is used in certain climates and 40 to 50 percent of the venting sits high in the attic. The area should be balanced roughly 50/50 between low intake and high exhaust. For a 1,500-square-foot attic at the 1/150 ratio, that is 10 square feet of net free area.

How can I tell hail damage from blistering on a shingle?

Hail leaves random, dented impact marks where granules are crushed into the surface and the fiberglass mat beneath may be bruised or fractured, often with a soft spot you can feel. Blistering shows up as small raised bubbles, sometimes popped, caused by trapped moisture during manufacturing or by a hot, under-ventilated attic, not by impact. Blistering tends to follow patterns and is usually a maintenance or ventilation issue, while hail damage is random and tied to a specific storm date.

What is the difference between a manufacturer warranty and a workmanship warranty?

A manufacturer warranty covers the roofing product itself against defects, and it is conditional on the roof being installed with the required accessories and to specification, which is why correct nailing, starter, and ridge cap matter. A workmanship warranty is the contractor's own promise covering the quality of the installation labor for a stated period. Both have terms and exclusions worth reading, and a strong roof job usually has both backing it.