Slate Roof Repair
The least durable, the Pennsylvania black slate, only has a life span of 50-70 years. After 20-3-
years the top layer wears off, delamination begins and over time the slates start crumbling.
Effective repair is nearly impossible as more slate is damaged in attempting a repair. In nearly
all cases with PA black slate, the end result is a total roof replacement.
With harder, longer-lasting slate, issues arise from flashing failures at valleys, around chimneys and walls, at vent pipes and other generations. Tin (no longer available) and copper are the most common metals used in re-flashing these details, although .032-gauge aluminum is an acceptable substitute for copper. Flashing details can be repaired without removing the whole roof; however,
this type of work requires a roofer experienced in working with slate.
Flashing details that are still in good condition often need a fresh application of polyurethane sealant - a material that remains flexible over time. Other areas that may require sealing include ridges and hips. Also, lower-sloped roofs are prone to failure because people will walk on them and break the slates. Then non-professionals perform poor repairs because the areas are accessible. The roof will still leak and this creates more traffic, resulting in a downward spiral of deterioration and ending with the slate roof needing replacement. The periodic inspection and maintenance of the slate by qualified, experienced personnel is essential to extending the life of the roof. Prescott Roofing, with over 114 years of experience to fall back on, is most qualified to address any issues with a slate roof.