A Helpful Glossary of Roofing Terminology

The following alphabetical list provides brief definitions for common phrases used when discussing roofing.

A

• Accelerated weathering – The process of magnifying the exposure of materials to light, heat, water and condensation to measure its weathering properties.
• Apron flashing – Flashing that is located at the juncture of the top of the sloped roof and a steeper sloped roof or vertical wall.

B

• Base flashing – Parts of roof membrane material used to close-off and/or seal a roof at the roof-to-vertical intersections such as at a roof-to-wall juncture.
• Butyl tape – A sealant tape used between metal roof panel seams and end laps. Also used to seal other types of sheet metal joints.

C

• Chalking – The degradation or migration of an ingredient in coatings, paints or other materials.
• Cleat – A metal plate, strip or angle piece used to secure two or more components together.

D

• Deflection – The downward displacement of a structural system under a load.
• Drip edge – Metal flashing with an outward projecting lower edge to control the direction of dripping water and protect underlying building components.

E

• Eave – A projecting edge of the roof that extends beyond the supporting wall.
• Efflorescence – Formulation of crystalline deposits on the surface of stone, brick, concrete or other surfaces when moisture moves through and evaporates on the masonry.

F

• Field of the roof – The primary or main component of a roof excluding the perimeter and flashing.
• Flashing – Used to weatherproof or seal the roof system at its edges, perimeters, walls, expansion joints, valley, drains and other places where the roof covering is interrupted or stops.

G

• Galvanised – Coated with zinc for corrosion resistance.
• Gambrel – A roof that has two pitches on each side.

H

• Hip Roof – A roof that rises by inclined planes to form one or more hips.

I

• Impact Resistance – The ability of a roofing material to resist damage from falling objects, foot traffic, etc.
• Impregnate – To coat, saturate or surround the fibers of a reinforcing mat or fabric with an enveloping liquid material.

J

• Joist – Beams arranged parallel from wall to wall to support a floor, ceiling or roof of a building.

L

• Lap – Part of a roofing or flashing component that overlaps or covers any portion of the same or other type of component.
• Lap Seam – Where overlapping materials are seamed, sealed or otherwise bonded.

M

• Mansard roof – A steeper roof that changes into a flat roof at its high point.
• Miter – A joint produced by joining two diagonally cut pieces.

N

• Night seal – Temporarily sealing a membrane edge during construction to protect the roofing assembly in place from weather.

O

• Open valley – A construction method where the steep-slope roofing on both sides are trimmed along each side of the valley, exposing the valley flashing.

P

• Pop rivet – A small headed pin with an expandable head for joining light gauge metal.

R

• Rake – The sloped edge of a roof at or adjacent to the first or last rafter.
• Ridge – The highest point on the roof, represented by a horizontal line where two roof areas intersect, running the length of the area.

S

• Sill flashing – Flashing of the bottom horizontal framing member of an opening, such as below a door or window.
• Step flashing – Individual pieces used to flash walls, around chimneys and other areas along the slope of a roof.
• Squash Fold – The edge created by folding metal back on itself.

T

• Tie-off – The transitional seal used to terminate roofing at the top or bottom of flashings or forming a watertight seal with the substrate, membrane or adjacent roofing.
• Thermal stress – Stress due to expansion and contraction caused by changes in temperature.

V

• Valley – The internal angle formed by the intersection of two sloping roof planes.
• Vapour retarder – Material installed to impede or restrict water vapour passing through a roof.

W

• Window hood – A decorative awning over the top of a window to protect from the weather.

Looking for Quality Roofing Supplies in Brisbane?

If you require roofing, flashings or other supplies for your next domestic or commercial building project in Queensland, get in touch with our team. At Rollsec, we provide premium metal roofing products to customers across Brisbane. Our range of steel products includes affordable and durable pre-painted roofing from Unicote Steel.

Call us today on 07 3041 4980 to discuss your requirements or contact us online.