On older roofs, high-quality clay tile or natural slate frequently outlast the original metal flashings and roofing underlayment, for example, asphalt-saturated felt paper that help to make the roof watertight. The question frequently facing building owners, contractors and architects is whether the old slate or clay tile are worth reusing.
Slate and Clay Tile Roofing Defy Father Time
May 30, 2004
Publication: Banker & Tradesman p 8-9