It was not only effect but also respect for the inherent qualities of the materials of building that encouraged the renewal of the graduated slate roof in roof replacement. In a lecture on “the Art of Building,” M.H. Baillie Scott, a leader with Charles Voysey in the promotion of the artistic house, urged the study of materials as the proper beginning of architecture: “If only instead of ignoring the qualities of materials and forcing them into meaningless forms, we were to begin at the other end, what a new world of art would be disclosed to us.” Scott considered the most important quality of roofing materials was texture. “Nothing,” he remarked, “is so fatal to the beauty of a roof as tiles which are absolutely regular giving the effect of a surface ruled with absolutely rigid horizontal lines. You might as well cover your building with galvanized iron at once.” Scott’s lecture, which was published in Construction in April 1910, advocated the use of the roughest and thickest slates but criticized slates generally for their failure to yield “to nature’s inimitable colouring.” This conclusion betrayed his experience of English slate and his ignorance of the gamut of fading and variegated slates in America. Curiously, despite its discussion and publicity, nearly a decade passed before the graduated slate roof appeared in Canada. The regular notices of domestic work in Construction first mentioned graduated slating in 1917 in a description of a “Georgian” red brick residence designed for L.C. Webster in Westmount, Quebec, which it stated, was covered with “rough green slates laid in graduating courses.” By 1919 two Toronto homes featured in the same magazine indicated varying colours as well as sizes were being used. The roof of a grey brick residence of classical English influence at Lonsdale and Dunvegan Roads was slated with a mixture of greys, greens and browns including both the unfading and the weathered varieties.
Slates of random widths and rough edges were laid with a free graduation toward the ridge. A similar roof of unspecified colours was also used to cover a green shuttered, white stucco home in Cedarvale.