The CIHB record also confirmed the hypothesis that slate roofing was used most on stone and brick buildings. Slate-roofed brick buildings were the common material mix in Canada as befitted the higher occurrence of slate structures in the brick country of Ontario. Yet in certain regions where slate was quarried nearby, slate replaced wood and asbestos shingling as the universal covering for all frame buildings ranging from homes to barns and sheds used by Toronto roofers.
This phenomenon was particularly evident in Newfoundland. Another example was Danville, Quebec, a centre for the quarrying and manufacture of school slate in the 1880s and 1890s. Here, nearly all the buildings recorded by the CIHB, most of them frame structures, were roofed with slate. The demographic portrait of slate roofing in Canada then is typically residential, eastern and urban, with greater concentrations in Toronto particularly and Ontario generally. Slate roofing is most commonly seen on brick and stone buildings, but in areas of local slate supply, slate covered every manner of building.
Historically, slate roofing reached its zenith in Canada during the 1880s although its use became common in mid 19th century and continued until the 1930s. How slate was used for roofing showed little geographic variation but appears to have changed with successive currents of architectural development.
The material itself defined the decorative option that became the basis of stylistic trends in slate roofing in Canada and elsewhere.