FAQ & Glossary

FAQ & Glossary: Frequently Asked Questions and a glossary of roofing terms

Frequently Asked Questions:

Q: What does hail do to my roof and why will my insurance company pay to replace my roof?

A: Hail damages the shingle mat, which holds the granules that protect the mat from the elements. As the shingle expands and contracts it will lose granules thus, exposing the mat, which in turn dries out and allows moisture to enter causing leaks and a eventual complete roof system failure.

Q: How I do I know if I have hail damage to my roof? Can I tell from the ground?

A: If you’ve had hail in your area, to determine if the shingles have been damaged a close inspection of the shingles has to be made from the roof. Usually you cannot tell from the ground.

Q: In my adjustment, my insurance company deducted some money for depreciation, what is that all about?

A: Different insurance companies call the amount that they hold back different things. Some call it depreciation; other companies figure it in as a dump and removal fee. What it represents is the amount of money the company will hold back until they receive a signed contract from you and a contractor for the work. When they receive a signed contract, you will receive another check for the amount they have held back.

Q: My insurance adjuster said there was no hail damage on his first inspection, I asked Insurance Specialist to call him and request to walk through a re·inspection with him. On the re·inspection the adjuster concluded that there was hail damage and “totaled” the roof. Why such a dramatic turn around?

A: In some cases the first adjuster has seen so many houses that day, he was fatigued, and at times smaller hail is harder to locate. Another possibility is that the adjuster could have not been experienced enough to determine the damage, so a more qualified person would need to be sent out. In some cases damage does not show up right away.

Q: What does hail do to a roof?

A: Shingles are designed so that the granules block the UV of the sun and protect the asphalt underlayment. As the shingles age the granules falloff over time. As the asphalt is exposed the UV, it dries out and the shingle gets a “potato chip” appearance as the corners start to curl up. A shingle at the extreme end of its life is bubbled in appearance and is brittle to the touch. A 20·year shingle is warranted by the manufacturer to have a useful life, under optimal ventilation conditions, of 20 years. Hail does several things: Accelerates granule loss. Accelerates shingle aging. Voids manufacturer’s warrantees. Leads to other associated problems.

Q: Do I need to get my roof replaced right away?

A: The insidious nature of hail damage is that it may pose no immediate threat to the structural integrity of the roof. However, many insurance companies have a “statute of limitations” of how long a hail claim is viable. If you have experienced a loss such as hail damage it is prudent to take care of the problem in a timely manner before it leads to other associated problems.

Q: What does hail hit look like?

A: A hail hit on a shingle looks like a “bruise” or a dark spot where the granules on the shingle have been knocked off and the asphalt underlayment and sometimes the fiberglass mat is exposed. New hail hits will have a shiny appearance because the asphalt has been freshly exposed and has not had time to weather to a dull color.

Q: If I think I have hail damage what should I do?

A: Sometimes adjusters get to a roof too soon after the actual damage and the hits haven’t had a chance to weather yet. Sometimes the adjusters are inexperienced. Sometimes they were tired after looking at so many roofs that day. Sometimes they just make mistakes. The best results for the benefit of homeowner seem to be obtained when an experienced roofer walks through the inspection with the insurance adjuster and calls to the adjuster’s attention any damage that he sees.

A roof glossary:

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Glossary sorted by category:
Types of roofs | Roof Features | Roof Framing | Roof Trusses | Roof Coverings

Glossary alphabetically sorted:

0-9 A B C D E F G H I J K L M N O P Q R S T U V W

    Aisled Barn

  • A type of roof truss construction that has aisles down the side to increase the span Aisled Barn page.
  • Anti ponding strip

  • In roofing, tiles and slating. A flat strip of metal flashing material fixed to the top o the fascia and to the rafters to stop the sarking sagging so that no water can pond inside the fascia. Anti ponding strip page.
  • Apron Flashing

  • A flashing that seals the top edge of a roof against a wall or chimney etc. Apron Flashing page.
  • Arcade post

  • A post at the side of a cruck truss to share the load and shorten the span. Usually seen in pairs in aisle barn construction. Arcade post page.
  • Arched brace

  • A curved brace, normally out of naturally curved timbers used to stiffen a roof frame. Usually in pairs. Arched brace page.
  • Asbestos containing roofing

  • Any roofing material containing asbestos fibres. Typically produced in corrugated sheets, imitation slates or imitation shingles. Banned as a new construction material since around 2000 in most countries. Asbestos containing roofing page.
  • Ashlar piece

  • Inside roof spaces, lofts and garrets, the short vertical pieces fixed between the floor and the rafters to form short walls. (Not to be confused with ashlar masonry). Ashlar piece page.
  • Ashlaring

  • The short side wall frames in lofts, attics, garrets etc. Ashlaring page.

    Barge or Verge Flashing

  • A flashing that seals the end of a roof against the verge or gable end. Barge or Verge Flashing page.
  • Bargeboard

  • A board or roll formed metal section fixed at the gable to finish and protect the roof to gable wall joint. Bargeboard page.
  • Barrel roof

  • A roof with a semi-circular cross section Barrel roof page.
  • Base cruck

  • The cruck blades sit at ground level and rase to be joined to a tie or collar beam. Base cruck page.
  • Belfast truss

  • A roof truss that has the top chord in the form of a circular or sometimes a parabolic arc. Known to be economical over large spans. Belfast truss page.
  • Belgian truss

  • Similar to a W truss or a Warren truss for longer spans with extra webs added. Also called a double Fink truss Belgian truss page.
  • Birdsmouth

  • A timber joint,a notch cut out of an angled piece to let it sit on a cross member. Typically in a rafter at the wall plate or at a underpurlin. Birdsmouth page.
  • Bowstring truss

  • A roof truss that has the top chord in the form of a circular or sometimes a parabolic arc. Know to be economical over large spans. Bowstring truss page.
  • Box gutter

  • A horizontal gutter at the intersection of two parallel roof surfaces. Box gutter page.
  • Boxed Eaves

  • An eaves that has been lined with the lining material level, rather than following the slope of the roof. Boxed Eaves page.
  • Butterfly roof

  • A roof that could be called an inverted gable roof. Both surfaces slope inwards from the walls to a central valley. Butterfly roof page.
  • Buttress

  • A mass of masonry bonded to an exterior wall. Usually to stiffen it against the lateral thrust of roof structures. Buttress page.

    C or cee purlins.

  • Cold rolled sections in the form of a letter “C”. Used not only for roofs but for wall girts and they are used by shed manufactures to form columns, ties and braces. They are also used for floor joists. C or cee purlins. page.
  • Cambered Fink or Cambered Warren truss

  • A Fink or Warren truss with a raised center bottom chord. Cambered Fink or Cambered Warren truss page.
  • Cantilever truss

  • A truss where one end is allowed to run over the support. Part of the truss is said to be a cantilever. Cantilever truss page.
  • Ceiling battens

  • Supported by and running at right angles to the ceiling-joists the battens typically timber or roll formed metal support the actual ceiling lining material. Ceiling battens page.
  • Ceiling joists

  • A wooden or steel beam supporting a a ceiling. Ceiling joists page.
  • Cement tile roofing

  • A roofing tile made out of cement or concrete based products. Available in many shapes and sizes. Cement tile roofing page.
  • Chimney cricket

  • A section of roof framing to divert rainwater around a chimney or short parapet. Chimney cricket page.
  • Clerestorey window

  • A window in the upper part of a wall and sometimes the lower edge of the roof to give light and ventilation to a high room. Clerestorey window page.
  • Collar Flashing

  • Any type of flashing that seals an object that passes through a roof. In particular now associated with proprietary fittings to suit various circular holes in roofs. i.e. vent pipes or extractor pipes. Collar Flashing page.
  • Collar tie

  • In timber roofs a member which spans two opposite rafters, usually at mid span between the wall plate and the ridge to stop the rafters spreading under load. Collar tie page.
  • Collar tie roof

  • A short span roof without a ceiling joist or other tie at the wall plates. A collar tie is used to create greater head height. Collar tie roof page.
  • Common rafter

  • A roofing timber that defines the slope of a roof. It is set at right angles to the wall plate and rises to the ridge board. Common rafter page.
  • Compass roof.

  • A pitched roof that has slight convex curves to the top surfaces. Depending on the amount of curve and the ratio of width to height they can range from almost a semicircle to a gothic arch. Compass roof. page.
  • Copper roofing

  • Flat sheets of copper used as a roofing material. Very long lasting. The typical green colour of an old copper roof is a layer of oxidisation that protects the material from further deterioration. Copper roofing page.
  • Corrugated iron

  • A roll formed flat sheet roofing product that when formed with the ridges and valleys becomes stiff and strong. Called iron because it was first made out of wrought iron. Corrugated iron page.
  • Counter batten

  • A batten laid in the opposite direction to tile and slate battens fixed to the rafters. Usually nailed over a boarded and felted roof to provide a space to stop water ponding at the normal battens. Counter batten page.
  • Couple close roof

  • A short span roof with ceiling joists as ties but no other roof ties. Couple close roof page.
  • Couple roof

  • A short span roof without a ceiling joist or other tie. The simplest of any ridged roof. Couple roof page.
  • Cripple rafter, Creeper rafter

  • A short rafter connecting a hip rafter and a valley rafter. Cripple rafter, Creeper rafter page.
  • Cruck blade

  • A single piece of timber when paired with another similar piece becomes a full cruck frame. Cruck blade page.
  • Cruck construction

  • A category of medieval architecture of unsure origin where the main load bearing members are crucks. Large section naturally bent timbers that reach from the height of the roof to the floors. Later they extended to low side walls. Cruck construction page.
  • Cruck Truss

  • 1.) One of a pair or naturally curved timbers used to form frames or trusses that were the main structural elements in medieval building in Northern Europe. 2.) A building that contains crucks or built using crucks. Cruck Truss page.
  • Curb

  • Curb is a name for the joint between the roof faces in gambrel and mansard roofs. Curb page.

    Dendrochronology

  • In old timber framed buildings it is used to date the time that trees were felled, and so the construction date, by various methods including study of the annual growth rings and carbon dating. Dendrochronology page.
  • Dendrology

  • The branch of botany involving the study of trees and shrubs. Dendrology page.
  • Dormer window

  • A vertical window placed in a sloping roof. Dormer window page.
  • Dutch gable

  • A lower part of a roof end that has a hip with an upper section with a gable. Dutch gable page.

    Eaves

  • The lower part of a sloping roof, the part of a roof which overhangs the walls. Eaves page.
  • Eaves brace

  • A brace between a wall and the eaves to increase the overhang at the eaves. Eaves brace page.
  • Eaves bracket

  • A bracket between a wall and the eaves to increase the overhang at the eaves. Eaves bracket page.
  • Eaves lining

  • A sheeting or lining material to seal the underside of an overhanging eaves or verge. Eaves lining page.
  • Eaves Vents

  • A series openings in the eaves to facilitate the movement of air inside a roof space. Eaves Vents page.
  • Eltham Palace Roof

  • The third largest example of a hammer beam roof in the UK, built to cover the great hall of the palace built for Edward 1V in the 15th century south of London. Eltham Palace Roof page.
  • End Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing at the end, that is in the direction of the slope. Higher overlaps lower by the amount of end lap. End Lap page.
  • Eyebrow

  • A low dormer type projection in a roof surface with no side walls. The roof surface flows over it in a curve. Eyebrow page.

    Fabric roofs

  • Roofs made from flexible membranes and tensioned cables. From simple shade structures to complex permanent structures. Fabric roofs page.
  • Fan truss

  • Similar to a W truss but with extra vertical ties added. Said that each sides web radiate like a fan. Fan truss page.
  • Fascia board

  • A horizontal board or roll formed metal fitting usually fixed vertically to the ends of the rafters Fascia board page.
  • Fascia gutter

  • 1.) A rainwater gutter that is fixed to a fascia board. 2.) A purpose made rainwater gutter that is fixed to the ends of the rafters and also performs the function of a fascia board. Fascia gutter page.
  • Fascia purlin

  • Usually in steel shed roofs, a rolled formed comnination of a fascia and a purlin. Can be ordred to suit varying roof pitches. Fascia purlin page.
  • Fascia stiffener

  • In an overhanging eaves, a horizontal timber behind the fascia at the hip corners to support the last jack rafters. Fascia stiffener page.
  • Finial

  • 1.)In architecture, a pure decoration or embellishment to the high points of a building. 2.) The top, round cap to flagpoles. 3.) Non construction related – Probably the most use it gets today is in the soft furnishing sections of stores, it is a name for the moulded caps to curtain rail ends. Finial page.
  • Flashing

  • A strip of sleeve of impervious material, or a non-ferrous metal or coated steel material that is formed to stop the entry of water. Flashing page.
  • Fly brace

  • A brace from the bottom flange of a rafter to a roof purlin that restrains the rafter laterally. Fly brace page.
  • French truss

  • A roof truss based on two Howe trusses and a bottom chord. A way of making a larger truss out of prefabricated elements of smaller trusses, French truss page.
  • Full Cruck

  • A cruck frame which reaches from the ridge to the floor using none jointed blades. Full Cruck page.

    Gable

  • The vertical triangular end of a pitched roof. It often is a continuation of the wall it is sat on or it can be made from different materials. Gable page.
  • Gable dormer

  • A vertical window placed in a sloping gable roof. Gable dormer page.
  • Gable roofs

  • A roof with two sloping surfaces from the ridge (usually in the center, joining at the side walls to form gable ends. Gable roofs page.
  • Gable Vent

  • A louvred vent in a gable wall. Gable Vent page.
  • Gablet

  • 1). A small gable that projects from another roof surface, similar to a dormer but with no walls. It can indeed be sat at the top of a gable end but the term is rarely used in this respect any more. 2). A triangular coping to a wall or buttress. Gablet page.
  • Galleria Roof

  • From the Italian word for gallery. The term is now loosely used to mean a roof over and between existing building to create a roofed public leisure and shopping space. Galleria Roof page.
  • Gambrel roof.

  • The gambrel has two slopes to each long side, the lower slope being much steeper. To better accommodate rooms inside the roof. A gambrel has gable walls on the shorter side. Gambrel roof. page.
  • Gang nail truss

  • One of a series of trusses made with light timber sections joined together with metal nail plates. Gang nail truss page.
  • Girder truss

  • A roof truss that acts a truss, but at the same time is built stronger than a standard truss of the same span to carry extra loads imposed on it. Used in nailplate truss construction. Sometimes consists of two or more standard trusses fixed together. Girder truss page.
  • Gutter outlet

  • 1.) An outlet for a gutter in a wall or parapet to allow water to drain off a roof. Gutter outlet page.
  • Gutter overflow

  • An extra gutter outlet or scupper at a higher level than the normal outlet. To safely direct the water outside if the main outlet gets blocked or is overloaded. Gutter overflow page.

    Half truss

  • Used in shed type roofs and lean to roofs, it is in effect half of a normal truss with a vertical member to complete the triangle. Half truss page.
  • Hammer Beam

  • Short horizontal beams built into and braced off the walls to help create larger open spans than would otherwise be possible with the means available at the time. Hammer Beam page.
  • Hammer Beam Truss

  • The ultimate development of timber roof truss design before the advent of modern materials, the hammer beam truss uses hammer beams extending a short way out from the walls to create an open and usually a highly decorative effect. The hammer beam roof is a peculiarly English creation with the finest example being in Westminster Hall. Hammer Beam Truss page.
  • Hammer Post

  • A vertical post from the open end of the hammer beam to the principal rafter. Hammer Post page.
  • Hampton Court Palace Roof

  • The second largest example of a hammer beam roof in the UK, built to cover the great hall of Henry V111’s Tudor Palace at Hampton Court on the banks of the Thames near London, UK Hampton Court Palace Roof page.
  • Hanging beam

  • A beam that is on top of the members that it is supporting. Typically used in ceilings where a conventional beam would look unsightly or would reduce limited head height. Hanging beam page.
  • Helm Roof

  • A roof usually to a rectangular tower that has four gables with the ridges riseing from the gables to give the effect of a sharpened stake. Used on steeples. Helm Roof page.
  • Hip

  • The meeting of two inclined roof surfaces. Hip page.
  • Hip flashing

  • The PM flashing of a hip to a roof sheeted with roll formed steel roofing. Hip flashing page.
  • Hip rafter

  • An inclined board immediately under the junction of two roof surfaces, the hip. To which are fixed the jack rafters. It runs from the corner of the wall plates up to the ridge. Hip rafter page.
  • Hip roof

  • A roof where the end surfaces also slope. Hip roof page.
  • Hip truss

  • One of a series of trusses made with light timber sections joined together with metal nail plates that sits in the hip position. Hip truss page.
  • Hipped gable

  • A roof that has a hipped end truncating a gable. Hipped gable page.
  • Howe girder

  • A girder or truss with horizontal chords and the diagonal members pointing down and towards the supports. Howe girder page.
  • Howe truss

  • A roof truss with vertical web members to take tension forces and with angled braces to take compression Howe truss page.

    Imbrex and Tegula

  • Two Latin words that together describe a system of terra cotta roofing tiles that go back to Ancient Greek and Roman Tiles. The Tegula is a flat pan with raised sides. The Imbrex is a semi-circular tile that caps the joint between the Tegulae. Imbrex and Tegula page.
  • Iron Roof Truss

  • A roof truss made out of either wrought iron, cast iron or more likely a combination or the two. Capable of large spans and often highly decorated. Iron Roof Truss page.

    Jack joists

  • Short joists at hip ends of hip roofs, running at right angles to the main ceiling-joists Jack joists page.
  • Jack rafter

  • A rafter that follows the same line as the common rafters, but it meets a hip instead of the ridge board. As a result it is shorter than the common rafters and has an inclined side or cheek cut where it meets the hip rafter. Jack rafter page.
  • Jack truss

  • Used in nail plate truss construction, a subsidiary truss that is fixed to a truncated truss with it’s top chord flying over to reach the hip. Where not fixed to a truncated truss it is fixed to a hip truss. Jack truss page.
  • Jointed cruck

  • A cruck with joints to the main members. To extend the length of the timbers or alter the shapes. Jointed cruck page.

    King post truss

  • A roof truss mostly wooden with two principal rafters, a tie beam and a central vertical King post. The simplest of trusses. Mainly used with two angled struts. King post truss page.
  • Knee brace

  • A brace between a post and beam, the bottom chord of a roof truss and the support, or a stiffener in a portal frame. Knee brace page.

    Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing. Usally referred to as either Side Lap or End lap. Lap page.
  • Lathe Hammer

  • Universal tool for fixing battens (prior to nail guns). Has an axe head for cutting battens, a hammer head for nailing them and a notch for drawing out bent nails. Lathe Hammer page.
  • Lattice Roof

  • A barrel or arched roof formed of many small sections fixed together to form the roof structure. They have been made out of RC concrete, timber, aluminium and steel. Lattice Roof page.
  • Lead roofing

  • Flat sheets of lead used as a roofing material. Very long lasting. Used for flat roofs and pitched roofs (usually out of sight) and extremely usfull for flashings because of its malleability. Lead roofing page.
  • Lean to roof

  • A single pitch roof. The lean to is exactly what it says, the top end of it leans against another structure. Lean to roof page.
  • Link dormer

  • A dormer that typically houses a chimney. Also used to join one part of a roof to another Link dormer page.

    Mansard roof

  • A roof that has two slopes to each side, the lower slope being much steeper. To better accommodate rooms inside the roof. Mansard roof page.
  • Mediterranean clay tiles

  • Also known as barrel or mission tiles in the US these semicircular with a taper are laid in alternate concave and convex rows. Mediterranean clay tiles page.
  • Metal ceiling battens

  • Made out of roll formed metal. similar but smaller in profile the roof-battens. Tek screwed to the ceiling joists, more often used in conjunction with gang nail truss construction. Metal ceiling battens page.
  • Metal Roof battens

  • Made out of roll formed metal. In a type of “top hat” section. Tek screwed to the rafters. Metal Roof battens page.
  • Moisture barrier

  • Any material sheet of membrane that prevents the undesirable flow of moisture into a building structure or for the control of condensation and water vapour. Moisture barrier page.
  • Monitor roof

  • A raised extension above a ridge that can provide light and ventilation to the room below. Monitor roof page.
  • Monospace truss

  • Used in shed type roofs and lean to roofs, it is in effect half of a normal truss with a vertical member to complete the triangle. The strut and web pattern is the same as a W truss. Monospace truss page.

    Ogee roof

  • A curved roof based on the “ogee” curve. Ogee roof page.

    Pantile

  • In the UK the name of traditional type of terra cotta or clay tile. “The Pantiles” is the name of an area in the town of Tunbridge wells, Kent, UK. Pantile page.
  • Parapet

  • 1.) The part of an exterior wall, gable or party wall that is entirely above the roof surface 2.) A low wall to guard the edge of a drop off. 3.) A defense wall. Parapet page.
  • Parapet gutter

  • A gutter at the intersection of a parapet wall and the bottom of a roof slope. Parapet gutter page.
  • Pavilion roof

  • Usually a roof set on a regular polygon with equal hips on all sides. Pavilion roof page.
  • Pendant

  • A suspended feature in gothic architecture, used in stone vaults and timber roofs. Also called a pendent. Pendant page.
  • Penetration flashing

  • Any type of flashing that seals an object that passes through a roof. In particular now associated with proprietary fittings to suit various circular holes in roofs. i.e. vent pipes or extractor pipes. Penetration flashing page.
  • Plastic roofing

  • Roofing material made for patios and decks etc. to allow varying amounts of light through the sheeting. Made from synthetic materials, fiberglass, polycarbonate etc. Plastic roofing page.
  • PM flashing

  • “Pressed metal” material usually 0.9mm thick in the same finish as the roofing. It is cut to length and width in a guillotine and then shaped in a brake press. The lengths of the individual flashings are governed by the size of the machine available. 6M. is common. PM flashing page.
  • Pole Plate

  • A horizontal member, steel or timber, fixed to the face of a wall to which roof framing is fixed. Typically rafters in a lean to type of roof. Pole Plate page.
  • Polygonal roof

  • Usually a roof set on a regular polygon with equal hips on all sides. It is seen a a decorative roof used in gardens and parks. Polygonal roof page.
  • Pratt girder

  • A girder or truss with horizontal chords and the diagonal members pointing down and towards the center. Pratt girder page.
  • Pratt girder

  • A truss or girder with alternate vertical and angled members between parallel chords. They angled members pointing down and towards the center. Pratt girder page.
  • Pratt truss

  • A truss with alternate vertical and angled members between the chords. They angled members pointing down and towards the center. Pratt truss page.
  • Principal rafter

  • One of the main diagonal members in in a roof truss on which the purlins sit, which in turn support the common rafters. Principal rafter page.
  • purlin

  • 1.) A horizontal roof member, steel or timber, sitting on the principal rafter of a truss or propped off a wall to support the rafters. AKA Under purlin. 2.) A horizontal roof member sitting on the rafters or on a truss or steel member that the roofing material is directly fixed to. AKA over purlin. purlin page.
  • Purlin bolts

  • Nut and bolt sets specifically designed for fixing cold rolled steel purlins. The bolt and nut heads have the washer with a serrated gripping surface formed integrally. Purlin bolts page.
  • Purlin bridging

  • Lightweight roll formed metal channel sections with proprietary end fittings used to stiffen Cee and Zed purlins Purlin bridging page.
  • Purlin cleat

  • 1.) Steel, a MS plate or angle punched to a set pattern of holes or slots to suit a particular size of steel purlins. Either welded or bolted to the support member. 2.) Timber, a short piece of timber fixed to a support member to hold timber purlins in position. Purlin cleat page.

    Queen post truss

  • A roof truss mostly wooden with two principal rafters and two vertical Queen posts with a restraining tie beam at the bottom and a straining beam at the top. Queen post truss page.

    Rainbow roof

  • A pitched roof that has slight convex cruves to the top surfaces Rainbow roof page.
  • Rainwater head

  • A funnel or boxlike head at the top of a down pipe or downspout for the collection of rainwater from a gutter outlet or overflow. Also know as:-rainwater header, rainwater sump, leader head, conductor head. Rainwater head page.
  • Raised cruck

  • A cruck truss that is raised to sit on usually short walls. Either masonry or timber. Raised cruck page.
  • Reducing truss

  • One of a set of nailplate roof trusses that sit on the backs of other trusses to form valleys. Reducing truss page.
  • RHS purlins

  • Rectangular Hollow Section. Often used as purlins on roof to decks and verandahs, where the structure is exposed to view. Usually the wall thickness used is 2.0mm or 2.5mm. Should always have welded end caps to seal the inside from corrosion. RHS purlins page.
  • Ridge

  • The apex of a roof. The highest point. Usually where two roof surface are parallel then the ridge is a horizontal intersection of the two. Ridge page.
  • Ridge board

  • A horizontal board immediately under the ridge of the roof to which the tops of the rafters are fixed. Ridge board page.
  • Ridge Vent

  • A horizontal vent to remove hot air etc. fixed to the ridge of a peaked roof. Ridge Vent page.
  • Roof battens

  • Horizontal members fixed to the top of the rafters the battens vary in size and spacing depending on the roof material that they carry. In the larger sizes sometimes called purlins. Roof battens page.
  • Roof framing

  • The total of the structural roof members which when connected form the support for the roof coverings Roof framing page.
  • Roof Vents

  • A series openings in a sealed roof to ventilate the roof space. Roof Vents page.
  • Roof verge

  • The edge of a gable roof at the gable wall. Sometimes flush with the wall and often has an overhang. Roof verge page.
  • Roofing felt, Underlay

  • A pliable water resistant membrane used beneath roofing and wall sheeting to collect and discharge any water or condensation. Usually combined with reflective foil and sometimes materials to give thermal insulation benefits. Also know as sarking. Roofing felt, Underlay page.
  • Roofing nail

  • Galvanised nails for fixing corrugated iron. About 65mm long with an integral washer they are now superseded by roofing screws. Roofing nail page.
  • Rotary Vent

  • A rotary spinning extractor vent, driven by wind power only, or by electric motor. Usually fixed towards the ridge of a peaked roof. Rotary Vent page.

    Sailover truss

  • A truss where each end cantilevers over the support. Used to get extra height at the wall plate or to simplify boxing in the eaves. Sailover truss page.
  • Sarking

  • A pliable water resistant membrane used beneath roofing and wall sheeting to collect and discharge any water or condensation. Usually combined with reflective foil and sometimes materials to give thermal insulation benefits. Also know as roofing underlay or underlayment and roofing felt. Sarking page.
  • Scissor truss

  • A truss with both the top chords and the bottom chords sloping upwards. To give a greater ceiling or clearance height. Scissor truss page.
  • Scotch valley, Blind valley, California valley

  • A method of constructing a variation to a rectangular plan without the use of valley rafters. The method that all Multinail roof truss manufactures use. Far stronger than a traditional framed valley but requires a beam across the walls. Scotch valley, Blind valley, California valley page.
  • Scupper

  • 1.) An outlet for a gutter in a wall or parapet to allow water to drain off a roof. 2.) A grill or other device to stop debris clogging a drain or gutter outlet. Scupper page.
  • Shed dormer

  • A vertical window placed in a sloping shed roof. Shed dormer page.
  • Shed roof

  • A roof that has only one slope. It is normally sat on two parallel walls that have different heights. The difference in height being the fall or pitch or the roof. Shed roof page.
  • Shingle clay tiles

  • Flat or slightly curved terracotta tiles fixed with similar laps and gauges to wood shingles or slates. Shingle clay tiles page.
  • Side Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing at the side, that is in a horizontal direction. Side Lap page.
  • Skillion roof

  • An Australian term for the same single slope roof, although it is often also applied to the lean to roof also. Skillion roof page.
  • Slate and a half

  • A wider than normal slate used at the side where otherwise the cut piece would be less than a half. Slate and a half page.
  • Slate axe, (ax), sax

  • A slater’s axe, has a point at the back of the head for making nail holes in the slate. For cutting slates. Slate axe, (ax), sax page.
  • Slate batten, Slate lathe

  • Horizontal strips of timber laid on top of the common rafters or on counter battens to which the slates are fixed. Slate batten, Slate lathe page.
  • Slate gauge

  • The spacing of the roofing battens Slate gauge page.
  • Slate margin

  • The amount of slate open to view. Slate margin page.
  • Slate ripper

  • A flat steel plate with notches on the end. Used in repairs to rip out the nails fixing broken tiles etc. German ripper has a nail pulling claw on hand end. Slate ripper page.
  • Slate roofing

  • A roofing material consisting of overlapping layers of slate. Slate roofing page.
  • Slate roofs

  • Roofing material made from natural slate. A sedimentary rock that has the ability to be split into thin layers. Slate roofs page.
  • Slater’s hammer.

  • A tool with a long sharp point for piercing the slate for nail holes and a hammer head for nailing, Slater’s hammer. page.
  • Sprocket-piece

  • 1.) A piece at the foot of a rafter to incline last section of the roof towards the horizontal, to make sprocked eaves. 2.) An outrigger piece attached to the end rafters at the verge of a gable roof to create a gable overhang. Sprocket-piece page.
  • Steel purlin

  • A horizontal roof member to which roofing is fixed. Mostly cold rolled galvanized steel but can be any steel section thin enough to be easily screwed to. Steel purlin page.
  • Stepped Flashing

  • A flashing that seals the sloping edge of a roof against a masonry or brick wall. Stepped Flashing page.
  • Straining beam

  • 1.) In a truss a horizontal strut above the tie beam. 2.) In a queen post truss the horizontal strut between the ends of the queen posts. Straining beam page.
  • Straining sill

  • A horizontal member in a timber roof, typically fixed to a tie beam to resist the sidways thrust of struts. Straining sill page.

    Terra cotta tiles

  • One of the oldest of roofing materials, these tiles are made from hard fired clay in many different shapes and patterns. Terra cotta tiles page.
  • Tie beam

  • 1.) A horizontal member in roof framing, fixed to the foot of rafters to stop them spreading. 2.) In truss construction, timber or steel, the bottom horizontal member. The bottom chord. Tie beam page.
  • Tie beam

  • 1.) A horizontal member in roof framing, fixed to the foot of rafters to stop them spreading. 2.) In truss construction, timber or steel, the bottom horizontal member. The bottom chord. Tie beam page.
  • Tie Rod Truss

  • A roof truss that uses tie rods for the members under tension, ties, and solid timber or metal for the compression members. Tie Rod Truss page.
  • Tile battens

  • In roofing they are the horizontal strips of timber nailed across the rafters to fix cement and clay tiles to. Tile battens page.
  • Tilt or tilting fillet, Cant strip

  • A extra piece of timber at the fascia to lift the bottom row of slates. Tilt or tilting fillet, Cant strip page.
  • Timber ceiling battens

  • Made out of timber. Fixed to the ceiling joists in the with serrated grip nails (mostly by by nail guns). Timber ceiling battens page.
  • Timber purlin

  • A horizontal timber or lumber roof member that supports the common rafters, or horizontal roof member to which roofing is fixed, either on the rafters or on trusses etc. Timber purlin page.
  • Timber Roof-battens

  • Made out of timber. Fixed to the rafters in the smaller sizes for slates and tiles with serrated grip nails (mostly by by nail guns), and in the larger sizes by various plate connectors or straps. Timber Roof-battens page.
  • Tracery

  • Curved openwork shapes in stone or wood of typical Gothic designs in windows openings or decorative screens. Tracery page.
  • Truncated truss

  • A standard truss that has been truncated or has had it’s top cut off. Usually to allow jack trusses to pass over it in hip roof design. The term girder truss truss is commonly applied as these trusses ofter act as a girder supporting the minor trusses abutting it. Truncated truss page.

    Upper cruck

  • The upper blades are sat on a tie beam and raise up to the ridge. Upper cruck page.

    Valley

  • The meeting of two inclined roof surfaces at a re-entrant angle. Valley page.
  • Valley jack rafter

  • A short rafter connecting a ridge board and a valley rafter. Valley jack rafter page.
  • Valley rafter

  • The main support timber directly under the valley intersection of two roof surfaces. It corresponds to the hip rafter in terms of the same slope and roofing angles. It supports the valley jack rafters and any valley creepers. Valley rafter page.
  • Vergeboard

  • A board or roll formed metal section fixed at the gable to finish and protect the roof to gable wall joint. Vergeboard page.
  • Vermin proofing

  • Protecting a building against the entry of rats and mice and other vermin. Particularly at the eaves. Usually by expanded metal mesh. Vermin proofing page.

    W truss

  • A triangular truss where the web members take the form of a W. W truss page.
  • Wall Plate

  • 1.) A horizontal member, usually timber bolted or otherwise fixed to the top of a wall to which the roof framing is fixed. 2.) A horizontal member, such as a steel plate fixed to a masonry or concrete wall to carry the end of a beam or to attach a beam to other members. 3.) A horizontal member, either at the top or bottom of a wall frame. Known as top plates or bottom plates. 4.) A board fixed to a vertical surface of a wall to which shoring or props are fixed. Note! when used for the purpose of fixing rafters against a wall then it is known as a Pole Plate. Wall Plate page.
  • Wall post

  • A vertical post against the wall under a hammer beam or tie beam and down to the corbel to secure the curved brace and help transmit roof loads to the corbel. Wall post page.
  • Warren girder or Parallel chord truss

  • Parallel top and bottom chords joined by any number of W webs. Warren girder or Parallel chord truss page.
  • Wattle and Daub.

  • A method of building walls using interlaced thin lathes or branches (wattles) that are roughly plastered over with clay (daub) typically as infill panels between timber framing. Wattle and Daub. page.
  • Westminster Hall Roof

  • The oldest and largest example of hammer beam roof, built to cover the large hall of Westminster Palace in London. Westminster Hall Roof page.
  • Whaleback roof

  • A pitched roof that has slight convex curves to the top surfaces. Depending on the amount of curve and the ratio of width to height they can range from almost a semicircle to a gothic arch. Whaleback roof page.
  • Wind brace

  • A structural member that stiffens a structure against the forces of the wind. It can be timber or metal, strut (in compression) or a tie (in tension). Wind brace page.
  • Wood shakes, Shingles

  • A roof covering made out of small wooden pieces lapped in a similar manner to roof slates. Wood shakes, Shingles page.

    Z or zed purlins

  • Cold rolled sections in the form of a letter “Z”. Used mainly in large roofs and as wall girts. Zeds have the ability to overlap at the joints giving them a great strength advantage over the Cee purlins. Also can be used as floor joists. Z or zed purlins page.

    Barrel Roof

  • A roof with a semi-circular cross section Graphics page.
  • Butterfly Roof

  • A roof that could be called an inverted gable roof. Both surfaces slope inwards from the walls to a central valley. Graphics page.
  • Collar Tie Roof

  • A short span roof without a ceiling joist or other tie at the wall plates. A collar tie is used to create greater head height. Graphics page.
  • Compass Roof.

  • A pitched roof that has slight convex curves to the top surfaces. Depending on the amount of curve and the ratio of width to height they can range from almost a semicircle to a gothic arch. Graphics page.
  • Couple Close Roof

  • A short span roof with ceiling joists as ties but no other roof ties. Graphics page.
  • Couple Roof

  • A short span roof without a ceiling joist or other tie. The simplest of any ridged roof. Graphics page.
  • Dutch Gable

  • A lower part of a roof end that has a hip with an upper section with a gable. Graphics page.
  • Fabric Roofs

  • Roofs made from flexible membranes and tensioned cables. From simple shade structures to complex permanent structures. Graphics page.
  • French Truss

  • A roof truss based on two Howe trusses and a bottom chord. A way of making a larger truss out of prefabricated elements of smaller trusses, Graphics page.
  • Gable Roofs

  • A roof with two sloping surfaces from the ridge (usually in the center, joining at the side walls to form gable ends. Graphics page.
  • Galleria Roof

  • From the Italian word for gallery. The term is now loosely used to mean a roof over and between existing building to create a roofed public leisure and shopping space. Graphics page.
  • Gambrel Roof.

  • The gambrel has two slopes to each long side, the lower slope being much steeper. To better accommodate rooms inside the roof. A gambrel has gable walls on the shorter side. Graphics page.
  • Helm Roof

  • A roof usually to a rectangular tower that has four gables with the ridges riseing from the gables to give the effect of a sharpened stake. Used on steeples. Graphics page.
  • Hip Roof

  • A roof where the end surfaces also slope. Graphics page.
  • Hipped Gable

  • A roof that has a hipped end truncating a gable. Graphics page.
  • Lattice Roof

  • A barrel or arched roof formed of many small sections fixed together to form the roof structure. They have been made out of RC concrete, timber, aluminium and steel. Graphics page.
  • Lean To Roof

  • A single pitch roof. The lean to is exactly what it says, the top end of it leans against another structure. Graphics page.
  • Mansard Roof

  • A roof that has two slopes to each side, the lower slope being much steeper. To better accommodate rooms inside the roof. Graphics page.
  • Monitor Roof

  • A raised extension above a ridge that can provide light and ventilation to the room below. Graphics page.
  • Ogee Roof

  • A curved roof based on the “ogee” curve. Graphics page.
  • Pavilion Roof

  • Usually a roof set on a regular polygon with equal hips on all sides. Graphics page.
  • Polygonal Roof

  • Usually a roof set on a regular polygon with equal hips on all sides. It is seen a a decorative roof used in gardens and parks. Graphics page.
  • Rainbow Roof

  • A pitched roof that has slight convex cruves to the top surfaces Graphics page.
  • Shed Roof

  • A roof that has only one slope. It is normally sat on two parallel walls that have different heights. The difference in height being the fall or pitch or the roof. Graphics page.
  • Skillion Roof

  • An Australian term for the same single slope roof, although it is often also applied to the lean to roof also. Graphics page.
  • Whaleback Roof

  • A pitched roof that has slight convex curves to the top surfaces. Depending on the amount of curve and the ratio of width to height they can range from almost a semicircle to a gothic arch. Graphics page.

    Apron Flashing

  • A flashing that seals the top edge of a roof against a wall or chimney etc. Graphics page.
  • Barge Or Verge Flashing

  • A flashing that seals the end of a roof against the verge or gable end. Graphics page.
  • Bargeboard

  • A board or roll formed metal section fixed at the gable to finish and protect the roof to gable wall joint. Graphics page.
  • Box Gutter

  • A horizontal gutter at the intersection of two parallel roof surfaces. Graphics page.
  • Boxed Eaves

  • An eaves that has been lined with the lining material level, rather than following the slope of the roof. Graphics page.
  • Ceiling Joists

  • A wooden or steel beam supporting a a ceiling. Graphics page.
  • Chimney Cricket

  • A section of roof framing to divert rainwater around a chimney or short parapet. Graphics page.
  • Clerestorey Window

  • A window in the upper part of a wall and sometimes the lower edge of the roof to give light and ventilation to a high room. Graphics page.
  • Collar Flashing

  • Any type of flashing that seals an object that passes through a roof. In particular now associated with proprietary fittings to suit various circular holes in roofs. i.e. vent pipes or extractor pipes. Graphics page.
  • Curb

  • Curb is a name for the joint between the roof faces in gambrel and mansard roofs. Graphics page.
  • Dormer Window

  • A vertical window placed in a sloping roof. Graphics page.
  • Eaves

  • The lower part of a sloping roof, the part of a roof which overhangs the walls. Graphics page.
  • Eaves Brace

  • A brace between a wall and the eaves to increase the overhang at the eaves. Graphics page.
  • Eaves Bracket

  • A bracket between a wall and the eaves to increase the overhang at the eaves. Graphics page.
  • Eaves Lining

  • A sheeting or lining material to seal the underside of an overhanging eaves or verge. Graphics page.
  • Eaves Vents

  • A series openings in the eaves to facilitate the movement of air inside a roof space. Graphics page.
  • Eyebrow

  • A low dormer type projection in a roof surface with no side walls. The roof surface flows over it in a curve. Graphics page.
  • Fascia Board

  • A horizontal board or roll formed metal fitting usually fixed vertically to the ends of the rafters Graphics page.
  • Fascia Gutter

  • 1.) A rainwater gutter that is fixed to a fascia board. 2.) A purpose made rainwater gutter that is fixed to the ends of the rafters and also performs the function of a fascia board. Graphics page.
  • Finial

  • 1.)In architecture, a pure decoration or embellishment to the high points of a building. 2.) The top, round cap to flagpoles. 3.) Non construction related – Probably the most use it gets today is in the soft furnishing sections of stores, it is a name for the moulded caps to curtain rail ends. Graphics page.
  • Flashing

  • A strip of sleeve of impervious material, or a non-ferrous metal or coated steel material that is formed to stop the entry of water. Graphics page.
  • Gable

  • The vertical triangular end of a pitched roof. It often is a continuation of the wall it is sat on or it can be made from different materials. Graphics page.
  • Gable Dormer

  • A vertical window placed in a sloping gable roof. Graphics page.
  • Gable Vent

  • A louvred vent in a gable wall. Graphics page.
  • Gablet

  • 1). A small gable that projects from another roof surface, similar to a dormer but with no walls. It can indeed be sat at the top of a gable end but the term is rarely used in this respect any more. 2). A triangular coping to a wall or buttress. Graphics page.
  • Gutter Outlet

  • 1.) An outlet for a gutter in a wall or parapet to allow water to drain off a roof. Graphics page.
  • Gutter Overflow

  • An extra gutter outlet or scupper at a higher level than the normal outlet. To safely direct the water outside if the main outlet gets blocked or is overloaded. Graphics page.
  • Hammer Beam

  • Short horizontal beams built into and braced off the walls to help create larger open spans than would otherwise be possible with the means available at the time. Graphics page.
  • Hammer Post

  • A vertical post from the open end of the hammer beam to the principal rafter. Graphics page.
  • Hip

  • The meeting of two inclined roof surfaces. Graphics page.
  • Hip Flashing

  • The PM flashing of a hip to a roof sheeted with roll formed steel roofing. Graphics page.
  • Link Dormer

  • A dormer that typically houses a chimney. Also used to join one part of a roof to another Graphics page.
  • Parapet

  • 1.) The part of an exterior wall, gable or party wall that is entirely above the roof surface 2.) A low wall to guard the edge of a drop off. 3.) A defense wall. Graphics page.
  • Parapet Gutter

  • A gutter at the intersection of a parapet wall and the bottom of a roof slope. Graphics page.
  • Pendant

  • A suspended feature in gothic architecture, used in stone vaults and timber roofs. Also called a pendent. Graphics page.
  • Penetration Flashing

  • Any type of flashing that seals an object that passes through a roof. In particular now associated with proprietary fittings to suit various circular holes in roofs. i.e. vent pipes or extractor pipes. Graphics page.
  • PM Flashing

  • “Pressed metal” material usually 0.9mm thick in the same finish as the roofing. It is cut to length and width in a guillotine and then shaped in a brake press. The lengths of the individual flashings are governed by the size of the machine available. 6M. is common. Graphics page.
  • Rainwater Head

  • A funnel or boxlike head at the top of a down pipe or downspout for the collection of rainwater from a gutter outlet or overflow. Also know as:-rainwater header, rainwater sump, leader head, conductor head. Graphics page.
  • Ridge

  • The apex of a roof. The highest point. Usually where two roof surface are parallel then the ridge is a horizontal intersection of the two. Graphics page.
  • Ridge Vent

  • A horizontal vent to remove hot air etc. fixed to the ridge of a peaked roof. Graphics page.
  • Roof Vents

  • A series openings in a sealed roof to ventilate the roof space. Graphics page.
  • Roof Verge

  • The edge of a gable roof at the gable wall. Sometimes flush with the wall and often has an overhang. Graphics page.
  • Rotary Vent

  • A rotary spinning extractor vent, driven by wind power only, or by electric motor. Usually fixed towards the ridge of a peaked roof. Graphics page.
  • Scupper

  • 1.) An outlet for a gutter in a wall or parapet to allow water to drain off a roof. 2.) A grill or other device to stop debris clogging a drain or gutter outlet. Graphics page.
  • Shed Dormer

  • A vertical window placed in a sloping shed roof. Graphics page.
  • Stepped Flashing

  • A flashing that seals the sloping edge of a roof against a masonry or brick wall. Graphics page.
  • Tracery

  • Curved openwork shapes in stone or wood of typical Gothic designs in windows openings or decorative screens. Graphics page.
  • Valley

  • The meeting of two inclined roof surfaces at a re-entrant angle. Graphics page.
  • Vergeboard

  • A board or roll formed metal section fixed at the gable to finish and protect the roof to gable wall joint. Graphics page.
  • Vermin Proofing

  • Protecting a building against the entry of rats and mice and other vermin. Particularly at the eaves. Usually by expanded metal mesh. Graphics page.
  • Wall Post

  • A vertical post against the wall under a hammer beam or tie beam and down to the corbel to secure the curved brace and help transmit roof loads to the corbel. Graphics page.

    Anti Ponding Strip

  • In roofing, tiles and slating. A flat strip of metal flashing material fixed to the top o the fascia and to the rafters to stop the sarking sagging so that no water can pond inside the fascia. Graphics page.
  • Ashlar Piece

  • Inside roof spaces, lofts and garrets, the short vertical pieces fixed between the floor and the rafters to form short walls. (Not to be confused with ashlar masonry). Graphics page.
  • Ashlaring

  • The short side wall frames in lofts, attics, garrets etc. Graphics page.
  • Birdsmouth

  • A timber joint,a notch cut out of an angled piece to let it sit on a cross member. Typically in a rafter at the wall plate or at a underpurlin. Graphics page.
  • C Or Cee Purlins.

  • Cold rolled sections in the form of a letter “C”. Used not only for roofs but for wall girts and they are used by shed manufactures to form columns, ties and braces. They are also used for floor joists. Graphics page.
  • Ceiling Battens

  • Supported by and running at right angles to the ceiling-joists the battens typically timber or roll formed metal support the actual ceiling lining material. Graphics page.
  • Collar Tie

  • In timber roofs a member which spans two opposite rafters, usually at mid span between the wall plate and the ridge to stop the rafters spreading under load. Graphics page.
  • Common Rafter

  • A roofing timber that defines the slope of a roof. It is set at right angles to the wall plate and rises to the ridge board. Graphics page.
  • Cripple Rafter, Creeper Rafter

  • A short rafter connecting a hip rafter and a valley rafter. Graphics page.
  • Fascia Purlin

  • Usually in steel shed roofs, a rolled formed comnination of a fascia and a purlin. Can be ordred to suit varying roof pitches. Graphics page.
  • Fascia Stiffener

  • In an overhanging eaves, a horizontal timber behind the fascia at the hip corners to support the last jack rafters. Graphics page.
  • Fly Brace

  • A brace from the bottom flange of a rafter to a roof purlin that restrains the rafter laterally. Graphics page.
  • Hanging Beam

  • A beam that is on top of the members that it is supporting. Typically used in ceilings where a conventional beam would look unsightly or would reduce limited head height. Graphics page.
  • Hip Rafter

  • An inclined board immediately under the junction of two roof surfaces, the hip. To which are fixed the jack rafters. It runs from the corner of the wall plates up to the ridge. Graphics page.
  • Jack Joists

  • Short joists at hip ends of hip roofs, running at right angles to the main ceiling-joists Graphics page.
  • Jack Rafter

  • A rafter that follows the same line as the common rafters, but it meets a hip instead of the ridge board. As a result it is shorter than the common rafters and has an inclined side or cheek cut where it meets the hip rafter. Graphics page.
  • Metal Ceiling Battens

  • Made out of roll formed metal. similar but smaller in profile the roof-battens. Tek screwed to the ceiling joists, more often used in conjunction with gang nail truss construction. Graphics page.
  • Metal Roof Battens

  • Made out of roll formed metal. In a type of “top hat” section. Tek screwed to the rafters. Graphics page.
  • Pole Plate

  • A horizontal member, steel or timber, fixed to the face of a wall to which roof framing is fixed. Typically rafters in a lean to type of roof. Graphics page.
  • Purlin

  • 1.) A horizontal roof member, steel or timber, sitting on the principal rafter of a truss or propped off a wall to support the rafters. AKA Under purlin. 2.) A horizontal roof member sitting on the rafters or on a truss or steel member that the roofing material is directly fixed to. AKA over purlin. Graphics page.
  • Purlin Bolts

  • Nut and bolt sets specifically designed for fixing cold rolled steel purlins. The bolt and nut heads have the washer with a serrated gripping surface formed integrally. Graphics page.
  • Purlin Bridging

  • Lightweight roll formed metal channel sections with proprietary end fittings used to stiffen Cee and Zed purlins Graphics page.
  • Purlin Cleat

  • 1.) Steel, a MS plate or angle punched to a set pattern of holes or slots to suit a particular size of steel purlins. Either welded or bolted to the support member. 2.) Timber, a short piece of timber fixed to a support member to hold timber purlins in position. Graphics page.
  • RHS Purlins

  • Rectangular Hollow Section. Often used as purlins on roof to decks and verandahs, where the structure is exposed to view. Usually the wall thickness used is 2.0mm or 2.5mm. Should always have welded end caps to seal the inside from corrosion. Graphics page.
  • Ridge Board

  • A horizontal board immediately under the ridge of the roof to which the tops of the rafters are fixed. Graphics page.
  • Roof Battens

  • Horizontal members fixed to the top of the rafters the battens vary in size and spacing depending on the roof material that they carry. In the larger sizes sometimes called purlins. Graphics page.
  • Roof Framing

  • The total of the structural roof members which when connected form the support for the roof coverings Graphics page.
  • Scotch Valley, Blind Valley, California Valley

  • A method of constructing a variation to a rectangular plan without the use of valley rafters. The method that all Multinail roof truss manufactures use. Far stronger than a traditional framed valley but requires a beam across the walls. Graphics page.
  • Sprocket-piece

  • 1.) A piece at the foot of a rafter to incline last section of the roof towards the horizontal, to make sprocked eaves. 2.) An outrigger piece attached to the end rafters at the verge of a gable roof to create a gable overhang. Graphics page.
  • Steel Purlin

  • A horizontal roof member to which roofing is fixed. Mostly cold rolled galvanized steel but can be any steel section thin enough to be easily screwed to. Graphics page.
  • Tile Battens

  • In roofing they are the horizontal strips of timber nailed across the rafters to fix cement and clay tiles to. Graphics page.
  • Timber Ceiling Battens

  • Made out of timber. Fixed to the ceiling joists in the with serrated grip nails (mostly by by nail guns). Graphics page.
  • Timber Purlin

  • A horizontal timber or lumber roof member that supports the common rafters, or horizontal roof member to which roofing is fixed, either on the rafters or on trusses etc. Graphics page.
  • Timber Roof-battens

  • Made out of timber. Fixed to the rafters in the smaller sizes for slates and tiles with serrated grip nails (mostly by by nail guns), and in the larger sizes by various plate connectors or straps. Graphics page.
  • Valley Jack Rafter

  • A short rafter connecting a ridge board and a valley rafter. Graphics page.
  • Valley Rafter

  • The main support timber directly under the valley intersection of two roof surfaces. It corresponds to the hip rafter in terms of the same slope and roofing angles. It supports the valley jack rafters and any valley creepers. Graphics page.
  • Wall Plate

  • 1.) A horizontal member, usually timber bolted or otherwise fixed to the top of a wall to which the roof framing is fixed. 2.) A horizontal member, such as a steel plate fixed to a masonry or concrete wall to carry the end of a beam or to attach a beam to other members. 3.) A horizontal member, either at the top or bottom of a wall frame. Known as top plates or bottom plates. 4.) A board fixed to a vertical surface of a wall to which shoring or props are fixed. Note! when used for the purpose of fixing rafters against a wall then it is known as a Pole Plate. Graphics page.
  • Wind Brace

  • A structural member that stiffens a structure against the forces of the wind. It can be timber or metal, strut (in compression) or a tie (in tension). Graphics page.
  • Z Or Zed Purlins

  • Cold rolled sections in the form of a letter “Z”. Used mainly in large roofs and as wall girts. Zeds have the ability to overlap at the joints giving them a great strength advantage over the Cee purlins. Also can be used as floor joists. Graphics page.

    Aisled Barn

  • A type of roof truss construction that has aisles down the side to increase the span Graphics page.
  • Arcade Post

  • A post at the side of a cruck truss to share the load and shorten the span. Usually seen in pairs in aisle barn construction. Graphics page.
  • Arched Brace

  • A curved brace, normally out of naturally curved timbers used to stiffen a roof frame. Usually in pairs. Graphics page.
  • Base Cruck

  • The cruck blades sit at ground level and rase to be joined to a tie or collar beam. Graphics page.
  • Belfast Truss

  • A roof truss that has the top chord in the form of a circular or sometimes a parabolic arc. Known to be economical over large spans. Graphics page.
  • Belgian Truss

  • Similar to a W truss or a Warren truss for longer spans with extra webs added. Also called a double Fink truss Graphics page.
  • Bowstring Truss

  • A roof truss that has the top chord in the form of a circular or sometimes a parabolic arc. Know to be economical over large spans. Graphics page.
  • Buttress

  • A mass of masonry bonded to an exterior wall. Usually to stiffen it against the lateral thrust of roof structures. Graphics page.
  • Cambered Fink Or Cambered Warren Truss

  • A Fink or Warren truss with a raised center bottom chord. Graphics page.
  • Cantilever Truss

  • A truss where one end is allowed to run over the support. Part of the truss is said to be a cantilever. Graphics page.
  • Cruck Blade

  • A single piece of timber when paired with another similar piece becomes a full cruck frame. Graphics page.
  • Cruck Construction

  • A category of medieval architecture of unsure origin where the main load bearing members are crucks. Large section naturally bent timbers that reach from the height of the roof to the floors. Later they extended to low side walls. Graphics page.
  • Cruck Truss

  • 1.) One of a pair or naturally curved timbers used to form frames or trusses that were the main structural elements in medieval building in Northern Europe. 2.) A building that contains crucks or built using crucks. Graphics page.
  • Dendrochronology

  • In old timber framed buildings it is used to date the time that trees were felled, and so the construction date, by various methods including study of the annual growth rings and carbon dating. Graphics page.
  • Dendrology

  • The branch of botany involving the study of trees and shrubs. Graphics page.
  • Eltham Palace Roof

  • The third largest example of a hammer beam roof in the UK, built to cover the great hall of the palace built for Edward 1V in the 15th century south of London. Graphics page.
  • Fan Truss

  • Similar to a W truss but with extra vertical ties added. Said that each sides web radiate like a fan. Graphics page.
  • Full Cruck

  • A cruck frame which reaches from the ridge to the floor using none jointed blades. Graphics page.
  • Gang Nail Truss

  • One of a series of trusses made with light timber sections joined together with metal nail plates. Graphics page.
  • Girder Truss

  • A roof truss that acts a truss, but at the same time is built stronger than a standard truss of the same span to carry extra loads imposed on it. Used in nailplate truss construction. Sometimes consists of two or more standard trusses fixed together. Graphics page.
  • Half Truss

  • Used in shed type roofs and lean to roofs, it is in effect half of a normal truss with a vertical member to complete the triangle. Graphics page.
  • Hammer Beam Truss

  • The ultimate development of timber roof truss design before the advent of modern materials, the hammer beam truss uses hammer beams extending a short way out from the walls to create an open and usually a highly decorative effect. The hammer beam roof is a peculiarly English creation with the finest example being in Westminster Hall. Graphics page.
  • Hampton Court Palace Roof

  • The second largest example of a hammer beam roof in the UK, built to cover the great hall of Henry V111’s Tudor Palace at Hampton Court on the banks of the Thames near London, UK Graphics page.
  • Hip Truss

  • One of a series of trusses made with light timber sections joined together with metal nail plates that sits in the hip position. Graphics page.
  • Howe Girder

  • A girder or truss with horizontal chords and the diagonal members pointing down and towards the supports. Graphics page.
  • Howe Truss

  • A roof truss with vertical web members to take tension forces and with angled braces to take compression Graphics page.
  • Iron Roof Truss

  • A roof truss made out of either wrought iron, cast iron or more likely a combination or the two. Capable of large spans and often highly decorated. Graphics page.
  • Jack Truss

  • Used in nail plate truss construction, a subsidiary truss that is fixed to a truncated truss with it’s top chord flying over to reach the hip. Where not fixed to a truncated truss it is fixed to a hip truss. Graphics page.
  • Jointed Cruck

  • A cruck with joints to the main members. To extend the length of the timbers or alter the shapes. Graphics page.
  • King Post Truss

  • A roof truss mostly wooden with two principal rafters, a tie beam and a central vertical King post. The simplest of trusses. Mainly used with two angled struts. Graphics page.
  • Knee Brace

  • A brace between a post and beam, the bottom chord of a roof truss and the support, or a stiffener in a portal frame. Graphics page.
  • Monospace Truss

  • Used in shed type roofs and lean to roofs, it is in effect half of a normal truss with a vertical member to complete the triangle. The strut and web pattern is the same as a W truss. Graphics page.
  • Pratt Girder

  • A girder or truss with horizontal chords and the diagonal members pointing down and towards the center. Graphics page.
  • Pratt Girder

  • A truss or girder with alternate vertical and angled members between parallel chords. They angled members pointing down and towards the center. Graphics page.
  • Pratt Truss

  • A truss with alternate vertical and angled members between the chords. They angled members pointing down and towards the center. Graphics page.
  • Principal Rafter

  • One of the main diagonal members in in a roof truss on which the purlins sit, which in turn support the common rafters. Graphics page.
  • Queen Post Truss

  • A roof truss mostly wooden with two principal rafters and two vertical Queen posts with a restraining tie beam at the bottom and a straining beam at the top. Graphics page.
  • Raised Cruck

  • A cruck truss that is raised to sit on usually short walls. Either masonry or timber. Graphics page.
  • Reducing Truss

  • One of a set of nailplate roof trusses that sit on the backs of other trusses to form valleys. Graphics page.
  • Sailover Truss

  • A truss where each end cantilevers over the support. Used to get extra height at the wall plate or to simplify boxing in the eaves. Graphics page.
  • Scissor Truss

  • A truss with both the top chords and the bottom chords sloping upwards. To give a greater ceiling or clearance height. Graphics page.
  • Straining Beam

  • 1.) In a truss a horizontal strut above the tie beam. 2.) In a queen post truss the horizontal strut between the ends of the queen posts. Graphics page.
  • Straining Sill

  • A horizontal member in a timber roof, typically fixed to a tie beam to resist the sidways thrust of struts. Graphics page.
  • Tie Beam

  • 1.) A horizontal member in roof framing, fixed to the foot of rafters to stop them spreading. 2.) In truss construction, timber or steel, the bottom horizontal member. The bottom chord. Graphics page.
  • Tie Beam

  • 1.) A horizontal member in roof framing, fixed to the foot of rafters to stop them spreading. 2.) In truss construction, timber or steel, the bottom horizontal member. The bottom chord. Graphics page.
  • Tie Rod Truss

  • A roof truss that uses tie rods for the members under tension, ties, and solid timber or metal for the compression members. Graphics page.
  • Truncated Truss

  • A standard truss that has been truncated or has had it’s top cut off. Usually to allow jack trusses to pass over it in hip roof design. The term girder truss truss is commonly applied as these trusses ofter act as a girder supporting the minor trusses abutting it. Graphics page.
  • Upper Cruck

  • The upper blades are sat on a tie beam and raise up to the ridge. Graphics page.
  • W Truss

  • A triangular truss where the web members take the form of a W. Graphics page.
  • Warren Girder Or Parallel Chord Truss

  • Parallel top and bottom chords joined by any number of W webs. Graphics page.
  • Wattle And Daub.

  • A method of building walls using interlaced thin lathes or branches (wattles) that are roughly plastered over with clay (daub) typically as infill panels between timber framing. Graphics page.
  • Westminster Hall Roof

  • The oldest and largest example of hammer beam roof, built to cover the large hall of Westminster Palace in London. Graphics page.

    Asbestos Containing Roofing

  • Any roofing material containing asbestos fibres. Typically produced in corrugated sheets, imitation slates or imitation shingles. Banned as a new construction material since around 2000 in most countries. Graphics page.
  • Cement Tile Roofing

  • A roofing tile made out of cement or concrete based products. Available in many shapes and sizes. Graphics page.
  • Copper Roofing

  • Flat sheets of copper used as a roofing material. Very long lasting. The typical green colour of an old copper roof is a layer of oxidisation that protects the material from further deterioration. Graphics page.
  • Corrugated Iron

  • A roll formed flat sheet roofing product that when formed with the ridges and valleys becomes stiff and strong. Called iron because it was first made out of wrought iron. Graphics page.
  • End Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing at the end, that is in the direction of the slope. Higher overlaps lower by the amount of end lap. Graphics page.
  • Imbrex And Tegula

  • Two Latin words that together describe a system of terra cotta roofing tiles that go back to Ancient Greek and Roman Tiles. The Tegula is a flat pan with raised sides. The Imbrex is a semi-circular tile that caps the joint between the Tegulae. Graphics page.
  • Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing. Usally referred to as either Side Lap or End lap. Graphics page.
  • Lead Roofing

  • Flat sheets of lead used as a roofing material. Very long lasting. Used for flat roofs and pitched roofs (usually out of sight) and extremely usfull for flashings because of its malleability. Graphics page.
  • Mediterranean Clay Tiles

  • Also known as barrel or mission tiles in the US these semicircular with a taper are laid in alternate concave and convex rows. Graphics page.
  • Pantile

  • In the UK the name of traditional type of terra cotta or clay tile. “The Pantiles” is the name of an area in the town of Tunbridge wells, Kent, UK. Graphics page.
  • Plastic Roofing

  • Roofing material made for patios and decks etc. to allow varying amounts of light through the sheeting. Made from synthetic materials, fiberglass, polycarbonate etc. Graphics page.
  • Roofing Nail

  • Galvanised nails for fixing corrugated iron. About 65mm long with an integral washer they are now superseded by roofing screws. Graphics page.
  • Shingle Clay Tiles

  • Flat or slightly curved terracotta tiles fixed with similar laps and gauges to wood shingles or slates. Graphics page.
  • Side Lap

  • (In Roofing) The amount by which roofing tiles, slates shingles flashings etc overlap each other to achieve waterproofing at the side, that is in a horizontal direction. Graphics page.
  • Slate Roofing

  • A roofing material consisting of overlapping layers of slate. Graphics page.
  • Slate Roofs

  • Roofing material made from natural slate. A sedimentary rock that has the ability to be split into thin layers. Graphics page.
  • Terra Cotta Tiles

  • One of the oldest of roofing materials, these tiles are made from hard fired clay in many different shapes and patterns. Graphics page.
  • Wood Shakes, Shingles

  • A roof covering made out of small wooden pieces lapped in a similar manner to roof slates. Graphics page.

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