Historial dating methods
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A weather-tight roof is basic in the preservation of a structure, regardless of its age, size, or design.
People within particular regions developed preferences for the local species of wood that most suited their purposes.
In New England and the Delaware Valley, white pine was frequently used: in the South, cypress and oak; in the far west, red cedar or redwood.
The plain or flat rectangular tiles most commonly used from the 17th through the beginning of the 19th century measured about 10" by 6" by 1/2," and had two holes at one end for a nail or peg fastener.
Sometimes mortar was applied between the courses to secure the tiles in a heavy wind.
Furthermore, there is an urgency involved in repairing a leaky roof since such repair costs will quickly become prohibitive.
Although such action is desirable as soon as a failure is discovered, temporary patching methods should be carefully chosen to prevent inadvertent damage to sound or historic roofing materials and related features.
A poor roof will permit the accelerated deterioration of historic building materials—masonry, wood, plaster, paint—and will cause general disintegration of the basic structure.
Slate continued to be used well into the 20th century, notably on many Tudor revival style buildings of the 1920s.
Replacement of particular historic details is important to the individual historic character of a roof, such as this rounded butt wood shingle roof.
In the mid-19th century, tile roofs were often replaced by sheet-metal roofs, which were lighter and easier to install and maintain.
However, by the turn of the century, the Romanesque Revival and Mission style buildings created a new demand and popularity for this picturesque roofing material.