Certificate III in Roof Tiling key terms

The angle at which a roof surface rises from horizontal, usually expressed in degrees or as a ratio. It controls drainage, material selection and the minimum lap required between tiles.

The lowest pitch a given tile type may be laid at, set by the manufacturer and the relevant standard. Laying below this figure risks water penetration driven by wind or capillary action.

The overlap distance where one tile covers the tile below it. Correct lap depends on pitch, tile profile and wind exposure, and it determines how much water is shed without entering the roof space.

The vertical overlap measured between the top edge of a lower tile and the top edge of the tile two courses beneath it. It is the key check that side laps and course spacing are correct.

A single horizontal row of tiles running across the roof. Courses are stacked from the eaves upward so each row overlaps the one below, shedding water down the slope.

The spacing between roof battens, calculated from tile length minus the required headlap. Getting the gauge right ensures tiles sit correctly and the top course meets the ridge neatly.

A horizontal timber or metal strip fixed over the rafters or trusses to carry the weight of the tiles and provide a fixing point. Batten size and fixing must match the tile load and span.

The sloping structural member that supports the roof covering, running from the ridge to the eaves. Rafters may be part of a truss or fixed individually, and they carry battens and sarking.

A prefabricated structural frame of timber or steel members designed to span between walls and support the roof. Roof tilers must not cut or alter trusses without engineering approval.

The member at the apex of the roof to which the top ends of rafters are fixed. It sets the ridge line and provides a base for ridge capping or ridge tiles.

The covering fixed along the ridge to close the gap between the two roof planes and shed water each side. It may be bedded in mortar or installed as a dry-fixed system.

The sloping external edge where two roof planes meet at an angle other than the ridge. Hips are covered with hip tiles or capping and require careful cutting of adjacent tiles.

The tiles or capping pieces fixed along a hip to weatherproof the junction of the two roof slopes. They are bedded or dry-fixed and finished to match the ridge detail.

The internal junction where two roof slopes meet and concentrate water flow. Valleys need a waterproof lining and carefully cut tiles so runoff is directed to the gutter without leaking.

A preformed tray, usually metal or plastic, laid in a valley to collect and carry water to the gutter. It must be installed before tiles and dressed to suit the tile profile.

A weatherproofing strip of metal or membrane used where the roof meets walls, chimneys, valleys or penetrations. Correctly dressed flashing prevents water tracking into the building at these junctions.

Flashing that covers the joint where a roof slope abuts a vertical surface such as a wall or chimney, sitting over the top course of tiles. It is often combined with side and back flashings.

Flashing formed in steps to follow the slope where a roof meets a masonry wall, with each piece lapped over a tile course. It sheds water onto the tiles rather than behind them.

A pliable membrane or foil-backed blanket laid over the rafters under the battens. It provides a secondary water barrier and, in some products, insulation and condensation control.

Moisture that forms when warm, humid air meets a cooler surface inside the roof space. Tilers manage it through ventilation, sarking selection and correct installation of insulation.

The method of securing tiles to battens using nails, screws, clips or mortar. Fixing requirements increase with pitch, wind classification and the position of the tile on the roof.

A metal clip that holds a tile down to the batten or to the tile below where nailing is impractical or extra restraint is needed. Clips are common at edges, hips and high-wind zones.

The force exerted on the roof by wind, calculated for the site and used to determine fixing, batten and tie-down requirements. Higher wind classifications demand more frequent and stronger fixings.

The lower edge of the roof that overhangs the wall, including the fascia and gutter line. Eaves detailing controls the first course of tiles and ventilation into the roof space.

The board fixed along the ends of the rafters at the eaves, carrying the gutter and closing the roof edge. It must be straight and securely fixed before gutters and tiles are installed.

The board fixed to the sloping edge of a gable roof, hiding the ends of the purlins and supporting the edge tiles or barge capping. It forms the finished edge of the gable.

The triangular section of wall at the end of a roof with two sloping planes. Gable roofs need barge boards, barge capping and careful edge fixing against wind uplift.

The channel fixed at the eaves or in a valley to collect rainwater from the roof and direct it to downpipes. Fall, bracket spacing and outlet size must be correct to avoid ponding.

The vertical pipe that carries water from the gutter to the stormwater drainage system. It must be securely fixed, sized to the roof area and connected to the correct outlet.

The mortar finish applied to ridge, hip and verge joints to seal and neaten them. Pointing must be mixed correctly and tooled so it bonds and sheds water.

A mix of cement, sand and water used to bed and point ridge capping, hip tiles and verges. The mix ratio and consistency affect adhesion, flexibility and long-term weather resistance.

A small opening left in mortar or flashing to let trapped water drain out. Weep holes prevent moisture building up behind cappings and flashings, which can cause rot or staining.

A clay roof tile fired at high temperature, known for its colour and long life. It is brittle, heavy and must be handled and cut with the correct tools and blade.

A roof tile manufactured from cement, sand and pigment, available in many profiles and colours. It is heavier than some alternatives and requires adequate batten and truss capacity.

A tool used to cut tiles to size at hips, valleys and edges, either by scoring and snapping or with a power saw. The correct blade and dust control are essential for a clean cut.

Systems and procedures used to prevent workers falling from roofs, including guardrails, harnesses, anchor points and edge protection. It must be planned and in place before work at height begins.

A safe work method statement: a written document that sets out high-risk construction tasks, the hazards involved and the controls to be applied. Workers must follow it and review it when conditions change.

A ladder with hooks or brackets designed to sit securely over the ridge or eaves for safe access to a roof slope. It must be rated, positioned correctly and used with fall protection.

A temporary structure providing a safe working platform and edge protection at height. It must be erected by competent persons, inspected and tagged before use.