Metal roofing quotes can look confusing because the important items are not only the panels. The quote is a roof system: geometry, underlayment, flashings, fasteners, ventilation, finish, and storm performance assumptions. This glossary is built for homeowners who want to compare quotes apples to apples and avoid missing line items that become delays, change orders, or leaks later.
How to use this glossary: when a quote uses a term below, confirm the quote specifies the exact product, quantity basis, and installation method. If a term is missing entirely, treat it as a potential scope gap.
Glossary section A: roof geometry and measurement
- 1) Square
- 100 square feet of roof surface area. Many material quantities and pricing are based on squares, not floor area.
- 2) Square foot
- A unit of area used in takeoffs. Roof surface square feet increase with pitch, so footprint square feet and roof square feet are not the same.
- 3) Roof plane
- A single flat surface of the roof with one pitch and one direction of water flow. Complex roofs have multiple planes that change trim and flashing requirements.
- 4) Pitch
- The steepness of the roof, usually expressed as rise over run. Pitch influences system eligibility, underlayment stack, and leak risk at low slope.
- 5) Rise over run
- The ratio that defines pitch, such as 6 over 12. This is used to calculate roof surface area and determine minimum slope requirements.
- 6) Low slope
- A roof area with a smaller pitch where water drains slower. Low slope zones often require stricter details and a more robust underlayment approach.
- 7) Eave
- The lower edge of the roof where water exits. Eave details control water entry into gutters, ice protection, and closure requirements.
- 8) Rake
- The sloped edge of a gable roof. Rake trim manages wind driven rain entry and creates a clean termination at the roof side.
- 9) Ridge
- The horizontal peak where two roof planes meet. Ridge details include ridge cap and often ridge ventilation components.
- 10) Hip
- A sloped peak where two roof planes meet at an outside corner. Hips require hip cap components and often closures depending on profile.
- 11) Valley
- The internal channel where two roof planes meet and water concentrates. Valleys are high volume leak risk zones and must be planned explicitly.
- 12) Dormer
- A roof structure that projects from the main roof, adding sidewalls, headwalls, valleys, and more flashing scope.
Glossary section B: panel systems and profile language
- 13) Standing seam
- A concealed fastener panel system where seams lock together vertically. Often chosen for a premium look and fewer field fastener penetrations.
- 14) Exposed fastener panel
- A panel system installed with gasketed screws through the panel face. Often lower cost upfront with long-term sensitivity to fastener and washer condition.
- 15) Rib panel
- A common exposed fastener profile with raised ribs. Rib geometry affects closure needs, water behavior, and fastening lines.
- 16) Panel gauge
- Thickness of the metal, commonly referenced as a gauge number. Thicker panels can reduce denting and oil canning perception and can change price.
- 17) Profile
- The shape of the panel or shingle system. Profile determines accessories, closures, flashing compatibility, and visual style.
- 18) Clip
- A concealed attachment component often used in standing seam systems. Clip type and spacing influence wind uplift performance and movement handling.
- 19) Hem
- A folded edge in metal trim or panels that stiffens the edge and improves water control at terminations.
- 20) Starter strip
- A starting component used in some systems to align and lock the first course or panel edge. Missing starter logic can stall installs.
- 21) Ridge cap
- The metal cap that covers the ridge. Ridge cap is part of the weather plane and often integrates closures and ventilation.
- 22) Closure strip
- A shaped filler that closes profile openings at eaves, ridges, or transitions to block wind driven rain, pests, and debris.
Glossary section C: underlayment and moisture layers
- 23) Underlayment
- The secondary water shedding layer beneath the roof surface. Underlayment type and placement zones matter for warranty safety and leak resilience.
- 24) Synthetic underlayment
- A durable underlayment category often used under metal roofing. Not all synthetic underlayments have the same heat rating or tear resistance.
- 25) Ice and water shield
- A self-adhered membrane used at eaves, valleys, and critical transitions to protect against backwater from ice or debris dams.
- 26) High temp underlayment
- An underlayment designed for higher roof surface temperatures. Often relevant for dark colors, full sun exposure, and certain metal systems.
- 27) Vapor barrier
- A layer intended to limit moisture vapor movement. Used incorrectly, it can trap moisture. Used correctly, it supports moisture control strategy.
- 28) Air barrier
- A layer or detailing approach that limits air leakage. Air leakage is a major cause of condensation and ice dam conditions in cold climates.
- 29) Ventilation baffle
- A channel at the eaves that preserves airflow from soffit intake above insulation. Baffles prevent insulation from blocking intake.
- 30) Drip edge
- Edge metal that directs water off the roof into the gutter path and protects fascia. Drip edge geometry matters more on fast-draining metal roofs.
Glossary section D: flashings and transition parts
- 31) Valley pan
- The metal flashing in the valley that carries concentrated runoff. Valley pan width, laps, and fastener exclusion zones reduce leak risk.
- 32) Sidewall flashing
- Flashing where a roof runs alongside a vertical wall. Sidewall details must resist wind driven rain and include a termination plan.
- 33) Headwall flashing
- Flashing where the roof terminates into a vertical wall. Headwalls need a positive water path back onto the roof surface.
- 34) Step flashing
- Individual flashing pieces used at shingled roof to wall intersections. Step flashing is layered with roofing courses to shed water safely.
- 35) Counterflashing
- A cover flashing that protects the top edge of base flashing, often at masonry chimneys or walls. It prevents water from entering behind base flashing.
- 36) Kickout diverter
- A diverter at the bottom of a sidewall that forces water into the gutter instead of behind cladding. Missing kickouts cause hidden wall rot.
- 37) Chimney cricket
- A small peaked structure upslope of a wide chimney that splits and redirects water around the chimney. It reduces backwater load and leak risk.
- 38) Pipe boot
- A flashing component that seals around a round penetration like a plumbing vent. Correct sizing and placement prevent long-term leaks.
- 39) Skylight curb flashing
- Flashing that integrates the skylight curb with the roof system. Skylights are high-risk penetrations and must be planned, not improvised.
- 40) Transition flashing
- Flashing used where the roof system changes plane, profile, or material. Transition flashings are common at porch ties, additions, and roof breaks.
Glossary section E: fasteners, tapes, and sealants
- 41) Gasketed screw
- A screw with a sealing washer used in exposed fastener systems. Correct seating, torque, and washer integrity drive leak resistance.
- 42) Stitch screw
- A smaller fastener used to join overlapping metal components, such as trim laps. Stitch screw placement should avoid high-flow water paths.
- 43) Butyl tape
- A compressible sealing tape used under trim flanges and laps. Butyl is often preferred for long-term compression joints in metal roofing.
- 44) Sealant
- A caulk-like product used to seal specific joints. Sealant should support good geometry, not replace it as the primary water barrier.
- 45) Fastener back out
- When screws loosen over time due to thermal cycling, substrate movement, or installation torque issues. Backed-out fasteners often leak before they look obvious.
- 46) Torque
- The rotational force applied when driving screws. Over-torque crushes washers. Under-torque leaves gaps. Consistent torque is critical for exposed fastener roofs.
Glossary section F: ventilation and building science terms
- 47) Intake ventilation
- Air entry points, usually at the soffit. Intake is required for ventilation to work and is commonly blocked by insulation without baffles.
- 48) Exhaust ventilation
- Air exit points, often at the ridge. Exhaust without intake is not ventilation. It is a common quote gap and performance risk.
- 49) Ridge vent
- A vent system at the ridge that allows warm air to exit. Ridge vents must be paired with adequate soffit intake to be effective.
- 50) Soffit vent
- A vent at the underside of the eave that provides intake. Soffit vent paths must remain open from soffit to attic.
- 51) Net free area
- The effective open vent area after accounting for screens and louvers. Vent sizing decisions should be based on net free area, not just vent size.
- 52) Condensation
- Moisture that forms when humid air contacts a colder surface. Condensation can mimic leaks and can damage decking, insulation, and fasteners.
Glossary section G: finishes, coatings, and corrosion language
- 53) PVDF
- A premium paint system often chosen for superior fade resistance and reduced chalking over time, especially in high sun exposure.
- 54) SMP
- A common paint system that often delivers strong value. Long-term appearance depends on product line, color selection, and environment.
- 55) Stone coated steel
- A metal roofing category with a granular stone surface, often used to mimic shake, shingle, or tile and to help mask minor impacts.
- 56) Galvanic corrosion
- Corrosion caused by contact between dissimilar metals in the presence of moisture. Managing compatible materials and isolating contact points prevents it.
- 57) Cut edge protection
- Methods used to protect exposed metal edges created by cutting. Cut edges are common corrosion start points if not handled correctly.
- 58) Chalking
- A powdery residue that can develop as paint weathers. Chalking changes the look of the roof and is often tied to long-term finish performance.
Glossary section H: storm performance and compliance terms
- 59) UL 2218 Class 4
- An impact resistance classification commonly referenced for hail performance. It applies to specific products under a specific test method and does not guarantee zero dents.
- 60) Wind uplift rating
- A performance measure of how well a roof assembly resists being lifted by wind pressure. Real uplift performance depends on the tested assembly, fastening or clip schedule, and edge-zone detailing.
How to use these terms to compare quotes and avoid missing line items
- Translate each quote into the same structure: roof system, underlayment stack, flashings, trims, closures, fasteners, ventilation, and delivery readiness.
- Circle any term used without specifics. Example: underlayment or flashing as needed. Then force the quote to specify type, placement, and quantity basis.
- Confirm the quote addresses the highest risk zones: valleys, sidewalls, headwalls, chimneys, skylights, and penetrations.
- Confirm ventilation is treated as part of the roof system, not optional, especially if your home has ice dam history or condensation history.
- Lock finish language: PVDF vs SMP vs stone coated. Ensure the quote identifies the exact system family and color.
Best next step
If you want the fastest path to a complete bill of materials and fewer surprises, use a Roof System Audit. It is designed to verify roof geometry inputs, confirm accessory completeness, and reduce missing-scope change orders that happen when quotes are vague.
