Water channeling down a façade is a sure way to age and ruin stone. At Treat Hall on the Denver campus of Johnson & Wales University, water from this balcony originally drained from a spout over the side. After the balcony was rebuilt with recycled stone from other projects, a matching downspout was installed. Above that, new copper flashing with a drip edge sheds water away from the stone.
The sandstone in this arch cracked and broke away as the building settled and shifted. The contractor cut out the damaged area, and cut a piece of recycled stone to tightly fit the space. Masons attached the “new” piece to the old with dowels and epoxy. Then they carved the graft, called a Dutchman patch, to match the surrounding stone.