Slate roofing will last for generations. But there are some items you need to consider before switching to a slate roof.
There Is More Than One Type of Slate — Many people picture slate roofing as black or dark gray uniformly textured pieces of rock. But the truth is that slate comes in many colors and textures depending on where it was quarried. The most durable types of slate are usually purple, non-fading green and the dark gray “Buckingham” slate. These varieties have been known to last 200 years. The more affordable “soft” slate is still a good option with its 90-year expected lifespan.
Mixing Different Flashing Types Is Not Good — Slate roofs require long-lasting flashing, which is why copper is often the material used for it. Inexperienced roofing contractors sometimes use stainless steel flashing with copper ones. While copper doesn’t corrode by itself, it may react with other metals in a process called galvanic corrosion. Corrosion defeats the purpose of investing in a long-lasting, non-corrosive flashing material in the first place.
Slate Roofing Uses Different Fasteners — Slate nails are not interchangeable with the fasteners used on asphalt shingles or metal roofs. They should be as long as twice as the thickness of the slate plus an inch and should be made of copper or stainless steel, keeping in mind the risks of galvanic corrosion. The nailheads should sit flush on the slate. If driven too deep, the slate would crack. Protruding nailheads would damage the slate right above it.
Slate Roofing Requires Strong Decking — Plywood or oriented strand board (OSB) are the most common decking material in use today. For most roofing systems, these decking materials are more than sufficient. Slate roofing, on the other hand, requires decking that can matches its weight, installation method and, most importantly, its lifespan. So, 3/4- to 1-1/2-inch thick plank boards are ideal for this purpose. Being made of solid wood, it will not delaminate or have glues that will deteriorate over time.
Brownstone Roofing is your leading provider of roof installation and storm damage repair. Give us a call at (502) 242-7947 (Kentucky) or (502) 443-9222 (Indiana). You can also fill out our contact form. We serve customers in New Albany, IN, and surrounding areas.