A good deal of our work involves repairing or restoring slate roofs. In Cuyahoga County alone, there are approximately 10,000 slate roofs, so we are pretty busy!
Types of Slate Roofs
In Northeast Ohio, most of the existing slate roofs are Vermont Slate and are typically green, grey/green, grey, purple, black and occasionally red. As these roofs age, the natural weathering of the stone will add some buff, tan and brown tones as well.
There are a few roofs in the Cleveland area with slate from Virginia. These slates are usually known as “Buckingham Slates” and are of extremely high quality and are a blue-black to grey-black color.
There are also a few soft Pennsylvania grey slate roofs left in the area. A Pennsylvania Slate roof may be repairable, but it is not considered restorable.
Slate Valley Repair
Typically a slate roof will out last the metal flashing, and often even copper flashing. Replacing deteriorated flashing is a common project for us. A proper closed valley has a separate piece of flashing at each course of slate-overlapping like step flashing, while an “open valley” features exposed copper. In an open valley, natural expansion and contraction of the slates will not wear through the center and slating nails need not puncture the flashing. This choice of valley system uses about 50% of the copper of a closed valley.
When we are able to, we salvage and reuse slates. In other cases we can use slates from our own stock of vintage, salvaged slates. We take a lot of pride in our ability to match color, size and texture of slates to produce a final repair that blends unnoticed into the existing roof.