Brick facade updating principles of relative dating of geologic events
It's easy to see why repointing by hand costs as much as a square foot.
Using an electric grinder with a diamond-tipped blade can cut the cost to per square foot, as long as the joints are more than ½-inch wide.
He doesn't fill the fresh mortar into the joint in one pass.
Instead, he makes three to four passes, each time pressing in a thin layer of mortar.
Repoint only when temperatures remain between 40 and 90 degrees Fahrenheit, even at night.
Cold makes mortar brittle, while heat dries it out and prevents hardening.
As always, both Machnickis are proud of that, although it once caused them some trouble.
Then he scoops a glob of the sticky gray mix out of a bucket and onto his plasterer's hawk.
Holding the hawk up to the wall, he scrapes fresh mortar into the joint with a narrow tuck-pointing trowel.
"Believe it or not: There are still contractors who think the harder the mortar, the sturdier the wall," he says.
Before the 1870s, when portland cement became commercially available, most masonry structures—the Egyptian pyramids included—were built using only lime and sand.