1216 Congress St.

HDLC Guidelines: Section 5, Page 4 of the Guidelines for Roofing state that a slate roof can last 60 to 125 years depending on the roof slope, stone properties, formation, installation quality and regularity of maintenance. A failing slate often slowly delaminates, chips and absorbs moisture, causing the deterioration process to accelerate over time. Problems with slate roofs are typically the result of localized failure since many of the roof accessories and fasteners do not have the same 100- year life span as the slate itself. To extend the serviceable life of a roof, property owners are encouraged to address localized problems as they become apparent, using a qualified slate roofer. If over 20% of the roof slates are damaged or missing, replacement of the roofing might be warranted, although property owners are strongly encouraged to make every attempt to match decorative patterns and colors with replacement materials. Dimensional or architectural fiberglass asphalt shingles are manufactured by several companies, simulating the shapes, color and variegated color appearance of slate.