Roofing Glossary
Every roofing term explained in plain English by licensed DFW contractors. From barge rafters to TPO membranes — understand your roof before you sign a contract.
Roof Components & Parts
Barge Rafter
A barge rafter (also called a fly rafter or verge rafter) is the outermost rafter on a gable roof that extends beyond the exterior wall to form the roof overhang at the gable end.
Drip Edge
A drip edge is an L-shaped metal flashing installed along the edges of a roof to direct water away from the fascia and into the gutter system.
Fascia
Fascia is the vertical finishing board mounted along the lower edge of the roof, covering the ends of the roof rafters and providing a mounting surface for gutters.
Soffit
Soffit is the material covering the underside of the roof overhang (eave), providing ventilation to the attic and protecting rafters from weather exposure.
Roof Flashing
Roof flashing is thin metal (aluminum, galvanized steel, or copper) installed at roof joints, valleys, and penetrations to prevent water infiltration.
Step Flashing
Step flashing consists of small L-shaped pieces of metal woven into each course of shingles where the roof meets a vertical wall, such as a dormer or chimney.
Roof Valley
A roof valley is the V-shaped channel where two sloping roof planes intersect, forming a natural pathway for water runoff.
Ridge Cap
Ridge cap shingles are specially designed shingles installed along the peak (ridge) of the roof where two slopes meet, providing a finished seal against water and wind.
Roof Cricket
A roof cricket (also called a saddle) is a peaked structure built behind a chimney or other roof penetration to divert water around the obstruction.
Roof Scupper
A roof scupper is an opening in the parapet wall or roof edge of a flat commercial roof that allows water to drain off the roof surface.
Parapet Wall
A parapet is a low wall extending above the roof line along the perimeter of a flat or low-slope commercial building.
Rake Edge
The rake is the inclined edge of a sloped roof that runs from the eave to the ridge along the gable end of the building.
Eave
The eave is the lower edge of a roof that overhangs the exterior wall, providing shade and directing water away from the building foundation.
Pipe Boot
A pipe boot (also called a pipe jack or vent boot) is a pre-formed flashing that seals the gap around plumbing vent pipes where they penetrate the roof surface.
Ridge Vent
A ridge vent is a continuous ventilation opening installed along the peak of a sloped roof, covered by a vent strip and ridge cap shingles, allowing hot air to exhaust from the attic.
Roofing Materials
TPO Roofing
TPO (Thermoplastic Polyolefin) is a single-ply white roofing membrane used on flat and low-slope commercial roofs, known for energy efficiency and heat-weld seam strength.
EPDM Roofing
EPDM (Ethylene Propylene Diene Monomer) is a synthetic rubber roofing membrane used on flat commercial roofs, known for its proven durability and 30+ year lifespan.
Modified Bitumen
Modified bitumen is a multi-layer asphalt roofing system for flat and low-slope roofs, reinforced with fiberglass or polyester and modified with rubber (SBS) or plastic (APP) polymers.
Roof Underlayment
Roof underlayment is a water-resistant or waterproof barrier installed directly on the roof deck beneath shingles or other roofing materials.
Roof Decking
Roof decking (also called sheathing) is the structural base layer of the roof — typically plywood or OSB panels nailed to the rafters or trusses, onto which underlayment and roofing materials are installed.
Ice and Water Shield
Ice and water shield is a self-adhering waterproof membrane installed on the roof deck in vulnerable areas such as valleys, eaves, and around penetrations before shingles are laid.
Roofing Systems
Cool Roof
A cool roof is any roofing system designed to reflect more sunlight and absorb less heat than a standard roof, reducing building cooling costs.
Standing Seam Metal Roof
A standing seam metal roof uses vertical metal panels joined by raised seams (ribs) that interlock to create a watertight connection without exposed fasteners.
Gable Roof
A gable roof is the most common roof shape in residential construction, consisting of two sloping planes that meet at a central ridge, forming a triangular wall section (gable) at each end.
Damage Types
Ponding Water
Ponding water is standing water that remains on a flat roof for more than 48 hours after the last rainfall, indicating a drainage problem.
Hail Damage
Hail damage to roofing materials includes bruised or cracked shingles, dented metal, punctured membranes, and compromised granule coverage caused by hailstone impact.
Wind Damage
Wind damage to roofs includes lifted, creased, or missing shingles, torn membrane sections, displaced flashing, and structural damage caused by sustained high winds or gusts.
Maintenance & Repair
Attic Ventilation
Attic ventilation is a system of intake vents (soffit/eave) and exhaust vents (ridge/turbine/power) that circulates air through the attic space to regulate temperature and moisture.
Roof Coating
A roof coating is a liquid-applied membrane (typically silicone, acrylic, or polyurethane) that creates a seamless waterproof layer over an existing commercial roof surface.
Silicone Roof Coating
Silicone roof coating is a liquid-applied, moisture-cured membrane that creates a seamless, UV-resistant, waterproof surface over existing commercial flat roofs.
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