Flashings, Valleys and Gutters on Slate Roofs in Sydney

Where roof slopes meet other slopes or vertical elements (such as parapets and chimneys) flashings, gutters and cappings are required. The most critical areas of a roof are box gutters, because their failure will allow large volumes of water inside the building. Lead was traditionally used for flashings to both slate and tiled roofs. Check that flashings and cappings are firmly in position and are not cracked, corroded or perished. The sheet is dated March 1998, online edition 2004.

Two NSW trade categories

Roof slating work includes using shingles or shakes (or imitation slates, shingles or shakes) and installing flashing, sarking, battens and valleys. Roof plumbing is any work involved in fixing, installing, renovating, altering, repairing and maintaining guttering, downpipes, roof flashing and roof coverings on any building or structure. The roof plumbing page adds that roof plumbing does not include work on coverings made of non-metallic tiles and slates. We conclude nothing about which category covers a given flashing: ask whoever quotes. Over A$5,000 in labour and materials, including GST, a contractor needs a NSW contractor licence for either.

Ask the provider which category the quote falls under, and what it assumes about the existing valleys and box gutters.

Is flashing roof slating or roof plumbing?

The NSW Government's roof slating page lists installing flashing and valleys within roof slating work, and its roof plumbing page lists roof flashing within roof plumbing. We cannot say which covers a given job, so ask whoever quotes.

What is the most critical part of a roof?

The NSW Heritage Office's sheet says the most critical areas of a roof are box gutters, because their failure will allow large volumes of water inside the building. The sheet is dated March 1998, online edition 2004.

What was lead used for?

Lead was traditionally used for flashings to both slate and tiled roofs.