A concrete footing. Even though the concrete hardening (technically known as curing) process begins quickly, you should leave the posts undisturbed for at least two days after pouring the concrete.

I’ve used concrete deck piers for many years. A deck post footing is simply a 20-inch or larger diameter pad of poured concrete down at the bottom of a hole that’s dug in solid soil.

The walls are rough, gray concrete marred by occasional cracks and craters. The floors also are concrete and stained an uneven earthy hue. But the space is not a work in progress. Nor is it the ...