Parging was a coat of mortar applied to the foundation wall below grade. The part of the wall that nobody sees. The part that sits in the dirt. The parging sealed the pores of the block or the stone and kept the groundwater from seeping through. Parging was waterproofing before they called it waterproofing. The mason troweled the mortar onto the foundation and the mortar filled the voids and the voids were where the water wanted to enter. The parging said no.

Parging was ugly. A rough smear of cement on a rough surface of block. Nobody smoothed it. Nobody painted it. Nobody cared what it looked like because nobody would ever see it. The backfill covered the parging the same day the mason applied it. The parging lived its entire life in the dark. Underground. Pressed against the earth. Holding the water back while the house above it stayed dry and the family above it stayed warm and nobody in the family knew the parging existed. The parging was the most selfless part of the building.

The parging cracked. The earth moved. The frost heaved. The foundation settled a quarter inch in twenty years and the parging cracked along the settlement line and the crack let the water in. The water found the crack the way water always finds the crack. The homeowner saw the wet spot on the basement wall and called a contractor and the contractor said your foundation is leaking. The foundation was not leaking. The parging was cracked. The parging took the blame for a problem that belonged to the earth.

Two coats. The first coat was the scratch coat. Rough. Scored with a notched trowel so the second coat would grip. The second coat was the finish coat. Smoother. Denser. The two coats together were maybe three-eighths of an inch thick. Three-eighths of an inch between the house and the water table. That is not much. That is enough. The parging did not need to be thick. The parging needed to be continuous. One gap in the parging and the water found it. Continuity was the strength. Not thickness. Not hardness. Continuity.

They spray tar now. Damp-proofing. A coat of asphalt emulsion sprayed onto the foundation wall with a hose. The tar goes on in ten minutes. The parging took a day. The tar is black and sticky and smells like a road in July. The parging was gray and gritty and smelled like the mason hands. The tar works. The parging worked. The difference is the tar has no hand in it. The parging was applied by a hand holding a trowel and the trowel left marks and the marks were underground and nobody would ever see them. The mason signed a wall that nobody would read. That is devotion.

See also: Pointing, Footing