Porch and concrete floor painting in Tacoma, built for wet feet

Water is the whole story. A wood porch floor fails when moisture gets into the end grain, the gaps between boards, or the underside, then swells the wood and pushes paint off from beneath. Before we coat anything, we check boards with a moisture meter and wait until they read about 15% or less. We also look at the porch from below if there is crawl space access, because a damp, unvented underside will keep pushing water up through even the best floor enamel.

Prep makes up most of the job. We scrape every loose flake, sand the floor so the remaining paint is dull and smooth, and seal open seams where boards meet the house. Bare spots get a bonding primer made for exterior wood floors. Then two coats of porch and floor enamel go on, rolled and back-brushed into the board gaps. Traffic waits until the second coat has cured enough, which can take longer in our cool, damp mornings than the can suggests.

It depends on how much moisture the concrete carries and what look you want. Concrete in the Puget Sound region stays damp much of the year, especially slabs poured on grade with no vapor barrier under them. Thick film coatings can trap that moisture and lift off in sheets. On those surfaces we often recommend a penetrating concrete stain or a breathable masonry coating instead. Where the slab is drier, such as covered stoops and entries, a quality porch and floor enamel looks crisp and lasts well.

Prep on concrete is different from wood. We pressure wash or scrub, remove efflorescence, the white mineral crust that forms on damp masonry, and then etch or lightly grind so the coating has something to grip. Cracks get a flexible patch, and spalled step edges are rebuilt with a repair mortar. On front steps we mix a fine anti-slip additive into the final coat, since a painted concrete step in a Tacoma November is slick without it.

Gloss enamel looks rich but turns slick in rain and morning dew, which is nearly every morning here from October through spring. We handle that in two ways. The first is choosing a satin or low-sheen floor enamel, which gives better traction than full gloss. The second is mixing or broadcasting a fine silica or polymer grit into the final coat. Polymer grit is gentler on bare feet and pet paws, while silica gives more bite on steep steps.

We usually put the grit only where people walk: steps, landings and the path to the door. That keeps the rest of the floor smooth and easy to sweep. If you have older family members or a step that has caused trouble before, we can add a contrasting stripe on each step nose so the edge is easy to see at night. These small details cost very little on a porch repaint and make the space safer through the wet months.