Roofing

• Bargeboard

  A bargeboard is an ornamental board, also known as a vergeboard, fastened to the projecting gables of a roof to provide strength, protection, and a finished aesthetic. Historically prominent in Gothic Revival and Victorian architecture, it serves the functional purpose of concealing and safeguarding the exposed end grains of horizontal roof timbers from weather elements like rain and wind. Beyond its structural role, a bargeboard is often richly decorated with intricate carvings, scrolls, or fretwork, contributing significantly to a building's architectural character and visual appeal.

• Dormer

  A small structure that projects from a sloping roof and holds a vertical window, bringing light, air, and headroom into the attic.

• Drip edge

  A drip edge is a specialized metal flashing, typically made of aluminum, galvanized steel, or copper, installed along the eaves and rakes of a roof to manage water runoff. Its primary function is to direct rainwater away from the fascia and roof deck and into the gutters, preventing water from seeping under the roofing materials where it could cause rot, mold, or structural damage. By creating a physical barrier and a clear path for drainage, the drip edge also protects against wind-driven rain and helps seal gaps to keep pests out of the attic, ultimately extending the lifespan of the entire roofing system.

• Eave

  An eave is the edge of a roof that projects horizontally beyond the exterior wall of a building, serving as a functional and aesthetic transition between the roof and the structure. Its primary purpose is to protect the building by directing rainwater away from the walls and foundation, while also providing shade to windows and walls to regulate interior temperatures. Eaves can be designed in various styles, such as open eaves with exposed rafters, closed eaves, or boxed-in eaves that utilize soffits and fascia boards to create a finished appearance and house ventilation systems for the attic.

• Facia

  A facia, or fascia board, is a long, thin horizontal band or board that runs along the lower edge of a roof, covering the ends of the roof rafters and providing a clean, finished appearance to the eaves. Functioning as a primary attachment point for gutters, it plays a critical role in moisture management by sealing the gap between the roof and the walls to protect the interior structure from water damage, pests, and debris. Beyond its functional utility in shielding the roof's edge and supporting the drainage system, the facia serves as a prominent decorative trim that helps define the building's profile and architectural style.

• Fascia

  The flat board fixed along the lower edge of the roof, across the ends of the rafters or trusses, that usually carries the gutter.

• Flashing

  Thin pieces of metal or waterproof membrane fitted at joints, edges, and openings in a roof or wall to direct water away and keep it out.

• Gable

  The triangular upper part of an end wall under a pitched roof, rising from the top of the wall to the ridge.

• Gable end

  A gable end is the vertical triangular portion of an exterior wall located between the edges of a dual-pitched roof. This architectural element extends from the level of the eaves to the ridge peak, serving as a critical structural component that supports the roof and provides lateral stability. Beyond its functional role in weatherproofing and shedding water, the gable end often defines a building's aesthetic character and can be customized with various materials, windows, or decorative ornaments like bargeboards and finials.

• Hip

  The inclined external angle where two sloping roof surfaces meet, or the rafter running along that junction; a hipped roof slopes on all sides.

• Mansard

  A four-sided roof with two slopes on each side: a steep, often dormered lower slope and a shallow upper slope, creating usable attic rooms.

• Purlin

  A horizontal roof member running parallel to the ridge, spanning between trusses, rafters, or frames to support roof sheeting or common rafters.

• Rafter

  One of a series of sloping members running from the ridge or hip to the wall plate, supporting the roof deck and covering.

• Ridge

  The highest horizontal line of a pitched roof, where two sloping roof surfaces meet; also the board or beam that runs along that peak.

• Roof deck

  A roof deck, also known as roof sheathing, is a fundamental structural layer of wooden boards or metal panels installed over a building's rafters or trusses to provide a flat, stable surface for the entire roofing system. It acts as the critical foundation that supports the weight of shingles, tiles, and environmental loads like snow, while also serving as a secondary moisture barrier and a base for insulation. In urban contexts, the term also refers to a flat, finished rooftop area designed as a functional outdoor living space for relaxation or entertainment.

• Roof plane

  A roof plane is a flat, two-dimensional surface that forms one side of a roof system, acting as a primary overhead plane that shelters a building's interior from environmental elements. In architectural design, multiple roof planes intersect at ridges, hips, and valleys to create complex roof geometries, or a single plane can be used for simpler structures like shed roofs. These planes define the building's massing and spatial volume, often extending beyond the exterior walls as overhangs to provide additional protection and define the architectural character of the structure.

• Roof vent

  A roof vent is a functional architectural component installed within a roof system to facilitate the circulation of air between the outdoors and the building's interior attic or rafter spaces. These vents are essential for regulating temperature and moisture levels, helping to prevent the accumulation of condensation that can lead to mold, rot, and structural degradation. They typically function as part of a balanced system consisting of intake vents, often located at the eaves or soffits to draw in fresh air, and exhaust vents, situated near the ridge or peak to expel warm, humid air. Available in various forms, including passive static louvers, ridge vents, and active power-driven fans, roof vents play a critical role in enhancing energy efficiency, protecting roofing materials from thermal stress, and extending the overall lifespan of the roof structure.

• Skylight curb

  A skylight curb is a raised frame, typically constructed from wood or metal, that is attached to a roof to provide a secure mounting base for a skylight. By elevating the skylight above the roof surface, the curb facilitates proper water drainage and prevents leaks caused by pooling water, snow, or ice buildup. This structural element acts like a box that the skylight fits onto—similar to a lid on a shoebox—and is a standard requirement for skylight installations on flat or low-pitched roofs to ensure a watertight seal and long-term durability.

• Truss

  A framework of members arranged in triangles to span between supports. A truss transfers loads primarily through tension and compression in its chords and web members.

• Underlayment

  Roofing underlayment is a water-resistant or waterproof barrier material installed directly onto the roof deck, positioned between the structural sheathing and the visible exterior roofing material like shingles or metal. It serves as a critical secondary line of defense against moisture intrusion, safeguarding the building's wooden structure from rot and mold if the primary roofing layer is compromised by high winds, ice dams, or driving rain. Common types include traditional asphalt-saturated felt, durable and tear-resistant synthetic membranes, and self-adhering rubberized asphalt used for waterproofing vulnerable areas like eaves and valleys. In addition to moisture protection, underlayment provides temporary weather shielding during construction, contributes to fire ratings, and creates a smooth, uniform surface for the proper installation of the final roof covering.

• Valley

  The sloping inside corner where two roof surfaces meet, forming a channel that collects rainwater and carries it down to the eaves.

• Verge

  A verge is the edge or border of a pitched roof that projects over the gable or end wall of a building. It serves as the transition between the roof surface and the vertical face of the gable, providing a finished line that helps protect the junction from weather infiltration. Typically, the verge is treated with mortar, tiles, or metal flashing to ensure a watertight seal, though it can also be finished with a decorative or plain board known as a vergeboard.