Roofing Terminology | A.M.J Metal Roofing

A – Z of Roofing

A.M.J Metal Roofing

Glossary of Roofing Terminology

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Browse through the roofing definitions below for the most commonly used terms within the roofing industry – you can never have too much knowledge, right?!


ANTICON BLANKET –  Installed above the battens directly underneath the roof sheeting. It is a lightweight insulation specifically designed for use in residential and commercial buildings, consisting of a glasswool blanket adhered to a water-resistant reflective foil facing, bonded together using a thermosetting resin.

APEX –  The points where the two slopes of the roof meet at the ridge. The tallest point of the roof.

APRON FLASHING –  A one piece flashing, such as is used at the lower side of a chimney that penetrates a sloping roof.

BARGE CAPPING –  A flashing that is used to fix the gable end of the roof where the sheets start and finish.

BATTEN –  A batten is a piece of timber or metal channel installed horizontally on top of the rafters to allow sheet metal to be laid and fastened.

BMT –  Base Metal Thickness is a term to describe the thickness of the metal used.

BAY WINDOW –  A window of varying shapes, projecting outward from the wall of a building, forming a recess in a room.

BOX GUTTER –  An internal concealed roof gutter between the slopes of a roof or between a roof and a parapet wall.

CLADDING –  Any material used to face a building or structure, otherwise known as wall cladding.

COLORBOND® –  COLORBOND® steel is produced with a ZINCALUME® base to provide corrosion resistance and then covered with a chemically applied conversion layer to enhance coating adhesion. On top of this goes a baked on epoxy primer and finally a baked on exterior grade top-coat.

CONTRACTOR –  One who agrees by written agreement or contract to supply materials and perform certain types of work for a specified sum of money.

DORMER WINDOW –  A vertical window or opening, coming through a sloping roof and usually provided with its own pitched roof. Often used in attics to add light and a pleasing design to the house.

DOWNPIPE –  A pipe for draining water from the rainwater gutters to the ground or storm water runoff system.

EAVES –  The lower part of a roof that overhangs the walls (external ceiling).

FALL –  The slope or pitch of a roof or gutter.

FASCIA –  A board fixed horizontally to the lower ends of the rafters, to which guttering is fixed.

FASTENERS –  Any of a wide variety of mechanical securement devices and assemblies, including nails, screws, clips and bolts, which may be used to secure various components of a roof assembly.

FINIAL –  Usually a pointed ornament at the top of a gable, hip junctions and dutch gables.

FIRE RATING or R. VALUE –  A value given for the resistance to heat transfer of a roof and/or wall system.

FLASHING –  Components used to weatherproof or seal the roof system edges at the perimeters, penetrations, walls and other places, such as vent-pipes, chimneys, valleys and joints at vertical walls.

GABLE –  The triangular end of a housed formed at the end of a pitched roof, from eaves level to apex – this is a traditional roof style.

GUTTER –  A shallow trough that is fixed under the edge of the roof, installed to assist in directly water to the downpipes.

GUTTER GUARD –  Purpose made perforated system installed over the gutter to prevent gutters clogging from leaves and other debris.

HIP –  The inclined external angle formed by the intersection of two sloping roof. The hip runs from the ridge to the eaves.

HIPPED ROOF –  A roof with four roof sections, coming together at a peak – roughly pyramidal in shape.

PARAPET WALL –  A perimeter wall which extends above the roof line.

PENETRATION –  Any object that passing through the roof (i.e a vent pipe penetrates the roof)

PONDING –  The accumulation of water at low lying areas on a roof.

PROFILE –  The shape and design of the materials.

PURLINS –  These run horizontally and parallel to the ridge beam and perpendicular to the roof slope. They are fixed on top of the rafters and help prevent roof sag.

RAFTER –  A rafter is a parallel beam that supports the roof and is part of the truss. It is the principal support for roofing materials.

RAINWATER HEAD –  Rainwater heads are an essential design element for buildings where internal box gutters are used. A rainwater head or sump is a container located between the gutter and downpipe that aids the flow of water away from the roof. It acts as an external overflow point to minimise water surges into the storm water system and aid the flow of water down the downpipe.

RIDGE –  The highest point on the roof, represented by a horizontal line where two roof areas intersect, running the length of the area.

ROOF PITCH –  The angle formed between a sloping roof surface and a horizontal line, usually expressed in degrees.

ROOF TRUSS –  A frame designed to carry the loads of a roof and it’s covering over the full span without intermediate support.

SAFETY RAIL or EDGE PROTECTION –  A rail type structure that gets fixed to the roof perimeter to assist in the fall protection of the workers or contractors. This is a Workplace, Health and Safety requirement and is required to be installed to areas where you can fall from one height to another.

SARKING –  Is a strong, moisture proof, reflective, foil paper like material which is placed over the roof battens or purlins and installed beneath the external roof covering.

SCAFFOLDING –  A temporary structure specifically erected to support access platforms or working platforms.

SCRIBING –  Cutting a piece of sheet metal to fit the profile of another to which it is to be fitted.

SKILLION –  A roof shape consisting of a single sloping surface.

SKYLIGHT –  A glazed window or translucent roof section fitted parallel to the roof slope to admit light.

SOFFIT –  The lining installed under the eaves between the fascia board and external wall.

SUMP –  A sump is usually attached between a box gutter and the downpipe. They collect storm-water before it is carried away by the downpipe and they also serve to catch any debris before it enters the downpipe.

VALLEY –  The internal angle formed by two inclined slopes of a roof. A metal ‘V’ shaped gutter is fixed in this area to direct water to the gutter.

VENT –  An opening or device used to permit air or vapor to exit an enclosed structure.

WINDOW HOOD – A decorative awning that covers the top of the window to protect from the weather. Fixed to a timber frame on the outside of the building.

WHIRLY BIRD –  Whirly birds are a type of semi-mechanical vent that can be installed on the roof to help remove heat from the ceiling cavity.

ZINCALUME® –  ZINCALUME® is steel that is dipped in a zinc based product to give it a protective coating.

Contact A.M.J today!

If you need a new roof or a damaged roof repaired, contact A.M.J Metal Roofing today. Our friendly team are the experts in all aspects of roofing, gutters, asbestos, skylights, and more. We work with our customers to find the best solution to their roofing needs and their budget. Based in Queensland, A.M.J Metal Roofing is proudly Australian owned and operated.

A.M.J Metal Roofing will give you a free, no-obligation quote on any installation or repairs needed for your roof. Our roof installers and repair team are the very best.

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