Laying Slate Roofs

The business of slating consisted chiefly in covering the roofs of buildings with slate and all the variations in sizes, laps and fastenings that that could entail. Slate covering was also influenced to an extent by other roof elements, particularly the form, structure, under sheathing and flashing. For any given historical period in Canada the best documentation or most complete description of local slate work is furnished by the extant slate roof. The building historian cannot hope to examine enough roofs to put together a picture of Canadian practice in this way. What I have done, however, is look at the practitioner, the roof contractors, the historic influences on the slating trade and the advice dispensed in builders’ handbooks and the how-to columns of Canadian architectural journals. Against this background, by sampling building specifications and historic and contemporary photos, it is possible to identify the highlights of Canadian slate roofing practice from mid-19th century to the 1930s.

In 1918, an American periodical published an article entitled “Who does the Slate Roofing in your town?” The question revealed the traditionally close association between the slater and other mechanics in the roofing process. It also showed the blending of roofing trades which was well underway in the heyday of slate roofing in Canada. At mid-19th century, building specifications clearly distinguished between the tasks of the slater, plumber and iron worker on the roof. As the century wore on the functions of each trade were increasingly blurred.” Slater’s specifications sometimes included lead or cop- per work and galvanized iron work. “Roofing” specifications described the work of several trades and roofers ads, reflected this grouping of expertise. The result was that contracts were awarded to roofing companies that provided all roofing services. It was to take advantage of this situation that the magazine Metal Worker, Plumber and Steam Fitter, in 1918, posed the question “Who Does the Slate Roofing…?” Urging his mechanics to learn slating, the editor argued: Tin for valleys, gutters and flashings is needed for slate roofing, and nobody can furnish and place it more advantageously than the tin roofer. This secures favor for his bid for the slate roofing contract. His thorough knowledge of the necessity of making everything wind, weather and waterproof insures care in laying the slate ….

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