Roof Components

The parts of a roof, from rafters and underlayment to flashing, gutters and vents. 50 entries.

• Apron and Headwall FlashingApron flashing is a continuous flashing where the top of a roof slope butts against a wall, or across the downhill face of a chimney.
• BargeboardA bargeboard is a board fixed along the sloping edge of a gable roof, covering the ends of the roof structure, often decoratively carved.
• Chimney Cricket (Saddle)A chimney cricket, or saddle, is a small ridged structure built on the uphill side of a chimney to divert water and debris around it.
• Chimney FlashingChimney flashing is the combination of apron, step or soaker, counter and back flashings, sometimes with a cricket, that seals a chimney where it passes through a roof.
• Cold RoofA cold roof is a pitched roof insulated at ceiling level, leaving a ventilated, unheated loft or attic space between the insulation and the roof covering.
• Collar Tie and Collar BeamA collar is a horizontal member joining opposite rafters above their base; depending on position it either resists sag (collar beam) or spreading (collar tie).
• Counter-FlashingCounter-flashing is a cap of metal fixed into or onto a wall or chimney that covers the top edge of the base or step flashing beneath it.
• DormerA dormer is a roofed structure, usually holding a window, that projects vertically from a pitched roof to add headroom and light to the space below.
• Downspout (Downpipe)A downspout, or downpipe, is a vertical pipe that carries rainwater from a roof gutter down to the ground, a drain or a storage tank.
• Drip EdgeA drip edge is a formed metal flashing fixed along the eaves and rakes that carries water clear of the fascia and protects the edge of the roof deck.
• Eave Protection (Canada)Eave protection is the Canadian building code requirement for a waterproof membrane at the lower edge of shingle, shake and tile roofs to resist ice-dam leaks.
• EavesThe eaves are the lower, horizontal edges of a roof that overhang the walls, shedding rainwater clear of the building.
• FasciaA fascia is the vertical board fixed along the ends of the rafters at the eaves, closing the roof edge and usually supporting the gutter.
• Hip (Roof)A hip is the external, sloping edge formed where two roof planes meet at an outside corner, running from the eaves up to the ridge.
• Ice and Water Shield (Self-Adhered Ice Barrier)Ice and water shield is a self-adhering polymer-modified bitumen membrane applied at eaves, valleys and penetrations to stop water backed up by ice dams.
• Kickout Flashing (Diverter)Kickout flashing is a bent piece of flashing at the bottom of a roof-to-wall junction that turns water away from the wall and into the gutter.
• King Post TrussA king post truss is a simple triangular roof frame with a single central vertical post rising from the tie beam to the apex.
• Lead SoakersLead soakers are small sheets of lead interleaved with each course of slates or tiles at an abutment, the UK and Irish counterpart of step flashing.
• Metal Roof FastenersMetal roofs are attached with screws, clips, cleats and nails whose metal must suit the panel, substrate and exposure.
• Metal Roof Paint Systems (Polyester, SMP, PVDF, Plastisol)Factory paint systems for metal roofing range from polyester and SMP to PVDF and thick plastisol, differing in durability, colour retention and cost.
• Pipe Boot (Vent Pipe Flashing)A pipe boot is a flashing collar that seals a plumbing vent or other round pipe where it passes through the roof covering.
• PurlinA purlin is a horizontal roof member running along the length of a roof, parallel to the ridge, that supports rafters or roof sheeting between main frames.
• PVDF Coatings (Kynar 500, Hylar 5000)PVDF coatings are factory-applied fluoropolymer paints for metal roofing, prized for long-term colour and gloss retention under strong sunlight.
• Queen Post TrussA queen post truss is a roof frame with two vertical posts set either side of centre on the tie beam, linked at the top by a straining beam.
• RafterA rafter is a sloping structural member that runs from the ridge or hip down to the wall plate and carries the roof deck and covering.
• Rain ChainA rain chain is a chain or series of linked cups hung from a gutter outlet that guides rainwater to the ground as a decorative alternative to a downspout.
• Rain GutterA rain gutter is a channel fixed along the eaves that collects water running off the roof and carries it to downspouts, protecting walls and foundations.
• Rake and VergeThe rake (US) or verge (UK) is the sloping edge of a roof at a gable end, running from the eaves up to the ridge.
• Ridge Board and Ridge BeamA ridge board is a non-structural board at the roof apex that rafters bear against; a ridge beam is a structural beam that carries the rafters' upper ends.
• Ridge VentA ridge vent is a continuous exhaust vent along the ridge of a pitched roof that lets warm, moist air escape from the attic through a slot in the deck.
• Roof Battens and Counter-BattensRoof battens are strips fixed across rafters to hang tiles, slates or sheets; counter-battens run up the slope beneath them to make a drainage gap.
• Roof FlashingRoof flashing is thin sheet metal or membrane installed at joints, edges and penetrations to direct water away from places where the roof covering is interrupted.
• Roof Pitch and SlopeRoof pitch describes how steep a roof is, expressed as rise over run (such as 6:12 or 6/12), as an angle in degrees, or as a percentage.
• Roof RidgeThe ridge is the horizontal line at the top of a pitched roof where two sloping planes meet; it is capped with ridge tiles, cap shingles or metal.
• Roof Sheathing (Roof Deck)Roof sheathing, or decking, is the layer of panels or boards fixed over rafters or trusses that forms the surface the underlayment and roof covering are attached to.
• Roof TrussA roof truss is a prefabricated or site-built triangulated frame that spans between walls to support a roof, replacing individual rafters and joists.
• Roof ValleyA roof valley is the internal angle where two sloping roof planes meet, forming a channel that collects and carries water down to the eaves.
• Roof VentilationRoof ventilation is the controlled flow of outside air through an attic or roof space, usually in at the eaves and out near the ridge, to remove moisture and heat.
• Roofing Fasteners (Nails and Screws)Roofing fasteners are the nails, screws and clips that secure decks, underlayments and roof coverings, chosen for holding power and corrosion resistance.
• Roofing Felt (#15 and #30)Roofing felt is a bitumen-saturated base sheet used as underlayment; in North America it is sold as #15 and #30 grades under ASTM D226.
• Roofing UnderlaymentRoofing underlayment is the water-resistant sheet laid over the roof deck or rafters beneath the roof covering, acting as a secondary barrier against water.
• Rosin Paper Slip SheetA rosin paper slip sheet is a layer of rosin-sized building paper laid under copper and other seamed metal roofs so the metal can slide over the underlayment.
• Skip Sheathing (Spaced Sheathing)Skip sheathing is roof decking made of boards laid with gaps between them, traditionally used under wood shingles and shakes to let them dry.
• Skylight and Roof WindowA skylight is a glazed opening in a roof that admits daylight; an opening skylight within reach of occupants is usually called a roof window.
• Snow Guards and Snow RetentionSnow guards are devices fixed to a roof to hold or break up snow and ice so it does not slide off in dangerous slabs; they are especially common on metal roofs.
• SoffitA soffit is the underside lining of a roof overhang, closing the space between the fascia and the wall, often fitted with vents.
• Standing Seam Clips (Fixed and Sliding)Standing seam clips are concealed brackets that hold panels down at the seams; fixed clips pin the panel, sliding clips let it move with temperature.
• Step FlashingStep flashing is a series of small L-shaped pieces woven into each course of shingles or tiles where a roof slope meets a sidewall or chimney side.
• Vapour-Permeable Underlay (Breather Membrane)A vapour-permeable underlay, or breather membrane, is a roof underlay that resists liquid water but lets water vapour pass, widely used in UK and European pitched roofs.
• Warm RoofA warm roof is a construction in which insulation follows the roof slope or sits above the deck, so the structure and roof space stay within the heated envelope.