Roofing Terms Glossary
A complete homeowner-friendly roofing glossary explaining common roofing terms, materials, components, installation details, roof shapes, ventilation concepts, metal roofing terminology, asphalt roofing terminology, flashing terms, drainage terms, and inspection language.
Alphabetical Index
A
A lightweight metal roofing material often used in coastal environments because it resists corrosion well.
Thicker laminated asphalt shingles designed to create a dimensional appearance.
Roofing shingles made with asphalt, fiberglass mat, and mineral granules.
The movement of air through the attic to reduce heat buildup, moisture, and condensation risk.
B
A flashing installed behind chimneys, curbs, or roof penetrations to divert water around the obstruction.
A wood or metal strip used as a mounting surface or spacing layer for some roof systems.
A static roof vent installed near the upper roof area to exhaust attic air.
A flexible sealing tape used in metal roofing seams, laps, trims, and flashing joints.
C
Flashing that covers the top of another flashing or roof transition to shed water.
A powdery surface residue caused by weathering of a paint or coating system.
Concealed metal clips used to attach standing seam panels while allowing thermal movement.
A valley design where roofing material covers or overlaps the valley area instead of leaving an open metal channel.
A protective painted or metallic layer applied to roofing materials for colour, corrosion resistance, or weather protection.
Flashing installed over base flashing, often at walls or chimneys, to prevent water entry.
D
The structural roof surface, usually plywood or OSB, that roofing materials are installed over.
Metal flashing installed at roof edges to direct water away from fascia and roof decking.
A roofed projection built out from a sloped roof, often containing a window.
A vertical pipe that carries water from gutters down to the ground or drainage system.
E
The lower edge of a roof where water exits into gutters or away from the building.
Metal flashing used at the roof eave to control water discharge and protect the deck edge.
Metal roofing where screws penetrate through the roof panel and remain visible.
The movement of roofing materials as temperatures rise and fall.
F
The vertical board or trim along the lower roof edge behind the gutter.
A screw, nail, clip, or connector used to secure roofing components.
Metal or membrane material used to direct water away from roof joints, edges, walls, valleys, and penetrations.
Repeated freezing and melting that can stress roofing materials and drainage systems.
G
A roof with two sloping sides meeting at a ridge and forming triangular walls at each end.
A steel coating made from aluminum, zinc, and silicon to improve corrosion resistance.
Steel coated with zinc to help resist corrosion.
A channel installed at the eave to collect and direct roof runoff.
H
Flashing used where a roof slopes into a vertical wall.
A roofing system where fasteners are concealed beneath panels, seams, or clips.
A roof where all sides slope downward toward the walls.
Structural connectors used to help tie roof framing to walls in high-wind regions.
I
Ice buildup at roof edges that blocks drainage and can force water under roofing materials.
A self-adhered waterproofing membrane used at eaves, valleys, and leak-prone areas.
A roofing material’s ability to resist damage from hail, debris, or falling objects.
A lower ventilation opening that allows fresh air to enter the attic.
J
A trim piece used to receive siding or panels at edges and transitions.
A connection point between two roofing components, panels, or flashing pieces.
K
A well-known PVDF coating brand used for long-term colour and weathering performance on metal roofing.
Flashing that diverts water away from a wall and into a gutter at roof-to-wall intersections.
L
An asphalt shingle made with multiple layers for added thickness and dimensional appearance.
The overlap between two roofing materials, panels, membranes, or flashing pieces.
Unwanted water entry into the roof assembly or building interior.
A roof with a shallow pitch that requires more careful drainage and waterproofing design.
M
A standing seam joint folded mechanically to lock panels together.
Roofing made from steel, aluminum, zinc, copper, or other metal materials.
Metal roofing panels shaped to resemble shingles, shakes, slate, or tiles.
A material used to reduce moisture movement into the roof assembly.
N
A wood member used as a fastening base for roofing components.
The open area of a vent that allows air to pass through after screens or louvers are considered.
O
Visible waviness in flat metal panels caused by stress, movement, substrate irregularities, or panel design.
A valley where metal flashing remains visible and acts as the main drainage channel.
Oriented strand board, a common roof sheathing material.
The portion of the roof that extends beyond the exterior wall.
P
A sheet or formed section of roofing material used to cover the roof surface.
A natural protective surface layer that forms on metals such as copper and zinc over time.
Any object or opening passing through the roof, such as a pipe, vent, skylight, or chimney.
The steepness of a roof, commonly shown as inches of rise per 12 inches of horizontal run.
A high-performance fluoropolymer paint system used on metal roofing for colour stability and UV resistance.
Q
The process of checking materials, installation, and workmanship to ensure roofing performance.
R
The sloped edge of a gable roof.
The highest horizontal line where two roof slopes meet.
Flashing or trim installed over the ridge to cover and protect the roof peak.
A ventilation opening installed at the roof ridge to exhaust attic air.
The structural surface installed over rafters or trusses that supports roofing materials.
Water flowing off a roof during rain or snowmelt.
S
A small roof-like flashing structure used to divert water around a chimney or obstruction.
A flexible material used to seal joints, flashings, and gaps. It should not replace proper flashing design.
The joint where two roofing panels or materials meet.
Roof deck panels, usually plywood or OSB, installed over framing.
Flashing installed where a roof slope runs beside a vertical wall.
The underside of the roof overhang, often containing intake vents.
A vent in the soffit that allows air to enter the attic.
A device installed on metal roofing to help control snow and ice movement.
A metal roof system with raised vertical seams and concealed fasteners.
A starting piece used at the roof edge to secure the first course of roofing material.
T
Removing existing roofing materials before installing a new roof.
Expansion and contraction caused by temperature changes.
A metal roof system where fasteners go through the panel face.
An engineered structural roof frame that supports the roof deck and loads.
U
A protective layer installed between the roof deck and roof covering.
Wind force that pulls roofing materials upward away from the roof deck.
V
The internal angle where two roof slopes meet and direct water downward.
Flashing installed in a roof valley to manage concentrated water flow.
A material used to slow moisture vapor movement through a building assembly.
The controlled movement of air through attic or roof spaces.
W
A written promise describing covered roofing materials, workmanship, or performance conditions.
A roof designed to move water downward and off the surface rather than remain watertight under standing water.
Rain pushed sideways or upward by wind, often entering weak flashing or vent details.
Negative pressure from wind that attempts to lift roofing materials away from the structure.
Z
A Z-shaped metal flashing or structural trim used in some roof and wall transitions.
A premium metal roofing material that develops a natural protective patina over time.