Slate and tile roof repair in Allentown

Slate from just up the road

Much of the slate on older Lehigh Valley houses came from close by. The Slate Belt in northern Northampton County, around Bangor, Pen Argyl and Wind Gap, had become the largest slate producing region in the world by 1903, according to the Pennsylvania Center for the Book. That is a big part of why so many brick homes and churches around Allentown still wear slate roofs today.

Repairs that respect the roof

A good slate repair is quiet: you should struggle to spot it from the street. That means:

• Replacement slates matched for size, thickness, color and texture, from new or salvaged stock
• Slates secured without exposed face nails, which leak and crack over time
• Flashing, valleys and ridges in long-lived metal such as copper where the roof calls for it
• No roofing cement smeared over slate as a fix, which traps water and makes later repairs harder

Clay tile follows the same principles: match the tile, respect the way it laps, and fix the metal underneath properly.

When a slate roof needs more than repairs

Slate itself can last a very long time, but the nails, flashing and underlayment holding it often fail first. The National Park Service guidance on historic slate roofs suggests evaluating a roof for repair rather than replacement when fewer than about 20 percent of the slates are damaged or missing and the roof is otherwise in good condition. Beyond that point, or where slates are flaking apart across the roof, replacing a slope or the whole roof becomes the practical choice.

For a longer look at that decision, read slate roof repair or replacement: how to decide.