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Philadelphia

Rowhome basements are their own trade.

A slab poured in 1925 with nothing but dirt under it does not behave like a 2005 suburban garage. We coat both. We just refuse to pretend they're the same job.

Why the paint keeps failing

When most of Philadelphia's rowhomes went up, nobody put plastic under a basement slab. Plenty were poured over what had been dirt floors. Ground moisture has been wicking up through that concrete ever since, and it announces itself in three ways: a white crusty bloom on the surface (the trade calls it efflorescence, and it's minerals the water carried up), paint that flakes off in sheets, and the damp smell that never quite leaves.

Every layer of paint a previous owner rolled on was an attempt to fight that moisture from the wrong side. The moisture always wins against paint. It pushes the coating off from underneath, which is why you're looking at three colors of failure down there right now.

Dampness decides the system

This is why we won't quote a rowhome basement off a phone call. We look at what the slab is actually doing first, and a damp slab usually tells on itself: the white bloom, the flaking layers, the smell after a wet week.

A slab that runs dry takes a standard system. A slab that runs damp needs the moisture-tolerant build, with a primer made for concrete a regular epoxy would blister off of. Either way the system gets matched to your slab before you sign, not discovered mid-job.

A century of floors, one at a time

The rest of the job is honest labor. We grind off every generation of failed paint down to sound concrete. We patch the dips and rebuild the rough spots a hand-poured 1920s slab always has. Then the system goes down: moisture-rated primer where the slab demands it, 100% solids epoxy, and a finish that turns the dampest room in the house into the cleanest.

The result reads nothing like painted concrete. It's a sealed, uniform, mop-friendly floor in a basement that spent a hundred years shrugging coatings off.

We coat 1920s basements like 1920s basements. The contractor who treats yours like a new garage slab is quoting you his next callback.