Slate & Tile Roofing in
Mercer, PA

The older homes in Mercer borough — particularly those built in the 1920s through the 1940s near the courthouse square on South Diamond Street and on the residential streets around the borough center — often have original slate roofing systems. Genuine Pennsylvania and Vermont slate is one of the densest roofing materials there is.

A properly installed slate roof from 1935 can still be performing in 2026, and many of them are. The problem is finding someone who actually knows how to work on it.

Most roofing contractors won't touch slate. It requires different tools, different technique, and knowledge of how to source matching material so the repair doesn't look like a patch. When a general roofer looks at an older Mercer home with broken slates, their default answer is often "full replacement" — because that's a job they know how to do. Because asphalt is what they sell.

We inspect the actual condition of the system before making any recommendation. If the underlying structure is sound and most of the field slates are intact, repair is almost always the right call. It costs a fraction of replacement and extends a system that already has decades of life remaining.

What We Assess on a Mercer Slate Roof

Slate roofing fails in specific ways. The most common failure mode is not the slates themselves — it's the nails. Original copper or hand-cut wire nails from early 20th-century installations can last 80-100 years, but when they finally begin to fail, slates start slipping and falling.

The slate is often fine. The fasteners are not. On these jobs, we nail-on or hook individual slates back using copper or stainless fasteners, or perform a partial re-nailing of the most vulnerable sections.

Other failure modes include:

• Broken slates — from impact (hail, falling branches) or from foot traffic by previous workers who didn't know what they were doing
• Failed ridge and hip flashings — lead, copper, and galvanized steel flashings at ridges and hips eventually crack and fail; the slate itself stays good while the flashings let water in
• Valley deterioration — open copper or lead valleys on older systems corrode at the center; replacing the valley without disturbing the field slates requires careful slate removal and reinstallation
• Deteriorated flashing at chimneys — step and counter flashing at chimneys is a common failure point on older Mercer homes; repointing the reglet and replacing the flashing metal stops the leak
• Soft spots — water that got past a failed flashing or missing slate has saturated deck boards. Those need to be replaced before new slate goes down

When Replacement Is the Honest Answer

We don't push repair when the system is too far gone. If the nails are failing uniformly across the full field, if more than 30-40% of the slates are broken or missing, or if the deck boards have been saturated long enough to delaminate in multiple areas, we'll tell you that replacement is the better path.

At that point we can replace with synthetic slate, which replicates the look without the weight penalty, or switch to a high-quality asphalt or metal system depending on your budget and how important the appearance is to you.