Repointing the Foundation

Most of the foundation dates to 1839-1840, when the church was constructed on its present site. The masonry is comprised of field stone, probably local, and averaging about 12 inches long by 4 inches tall, held together with a sand and lime mortar.

There were a few spots, including the back left corner, where a few stones were out of place. Multiple spots were in need of repointing, with missing mortar.

Proper restoration of the foundation required following the NPS guidelines on historical preservation. That included sending a sample of the mortar to a speciality lab to identify its specific composition and color. That’s important for more than aesthetics. The mortar must match the original’s hardness and strength. Otherwise, different sections of mortar could expand and contract at different rates, leading to cracking, heaving and damage. Oftentimes, old building foundations are repointed with modern Portland cement mortar – that’s a big no-no! It not only looks bad, but actually weakens the foundation.

So the first step was sending the mortar sample to “Chicago lab”. Analysis. Ordered historically matched.

Mike Malone of Malone masonry, a second-generation mason, performed the work over a few days.