Slate Roofing

Slate is the pinnacle of roofing materials, a natural stone product that has protected buildings for centuries and continues to grace the finest homes in Chicago's most distinguished neighborhoods. Properties along the North Shore, in Beverly, Lincoln Park, and Oak Park's Frank Lloyd Wright Historic District frequently feature slate roofs that have endured 75 to 100 years of Midwestern weather with remarkable grace, their split-stone surfaces developing a patina that only adds to their character over time.

Installing or restoring a slate roof requires specialized knowledge that most general roofing contractors do not possess. Slate tiles are heavy, averaging 800-1,500 pounds per roofing square, and demand a structural framing system engineered to support the load. Each tile must be sorted by thickness, punched for nail holes at the correct location, and hung with copper or stainless steel fasteners that match the slate's extraordinary lifespan. Improper technique leads to cracked tiles, displaced courses, and leaks that damage the very beauty the homeowner invested in.

Cornerstone Roofing Co. maintains a dedicated slate division staffed by craftsmen trained in both new installation and the delicate art of slate repair and restoration. We source domestic slate from quarries in Vermont, Pennsylvania, and Virginia, as well as imported Welsh and Spanish slate for projects requiring specific color or texture profiles. For homeowners who love the look of slate but need a lighter, more budget-friendly alternative, we also install composite slate products from DaVinci and Brava that replicate natural stone's appearance at a fraction of the weight and cost.

Slate performs exceptionally well in Chicago's climate because it is virtually impervious to water absorption. Unlike porous materials that swell and crack during freeze-thaw cycling, quality slate absorbs less than 0.25% of its weight in water, meaning ice formation within the stone is essentially nonexistent. The primary climate concern is ice dam formation at the eaves, which can back water under the lower courses. Cornerstone addresses this with generous ice-and-water shield underlayment and proper eave ventilation to minimize attic heat loss that triggers ice dams.

Slate costs three to five times more than architectural asphalt shingles, but its 75-150 year lifespan means a single installation can outlast three or four asphalt roofs. For owners of historic homes, slate also maintains architectural authenticity that is often required by local landmark commissions. Composite slate alternatives from DaVinci and Brava offer the slate look at roughly 60% of the cost and one-third of the weight, making them suitable for structures that cannot support natural stone's load.