Deck Painting & staining throughout Randolph, MA.

The census counts 8,233 single-family detached homes, 62.9% of all housing units, plus 1,272 attached units, and 71.3% of occupied homes are owner-occupied. The 2013 preservation plan describes the postwar subdivisions, mostly modest ranches and Capes, laid out on open land and former farms throughout town.

A deck added to a ranch decades after it was built, a newer deck on a 2010s house (the census counts 1,142 units from that decade), and a painted porch on an older home each start from different wood and different coatings. The first step is figuring out which you have.

The ground under the deck

The state's 1979 survey describes Randolph as rocky, glacially shaped uplands with several wetland areas, two large ponds and numerous bogs and swamps. If your lot borders a wet area or slopes toward the deck, the boards and framing near the ground can stay damp long after rain. Shade from trees has a similar effect.

Damp, shaded decks grow mildew and algae, and stain applied over either will fail early. Cleaning with a deck cleaner, rinsing, and letting the wood dry for a few days comes before any coating. Clearing leaves out of the gaps between boards and keeping soil and mulch from touching the lowest boards also help the wood dry between storms.

Stain or paint?

Penetrating stains soak into the wood instead of forming a film on top, so they wear away rather than peel. A transparent or semi-transparent stain shows the grain and is simpler to recoat later; a solid stain hides more and lasts longer on the vertical parts but can wear through on stair treads and walk paths. Paint and solid deck coatings give the most color coverage, but once a film starts to peel, the next round of prep involves more scraping.

Pressure-treated pine, cedar and composite all take finishes differently. New pressure-treated lumber may need weeks to dry out before it accepts stain, which a simple water-drop test can show: if water beads on the surface, wait. Cedar takes oil-based and waterborne stains well once mill glaze is removed. Composite usually needs only cleaning, unless you want to change its color with a coating made for it.

• Wash, mildew treatment and rinse
• Stripping or sanding failed coatings
• Flagging loose or rotted boards before any coating goes on
• Stain or paint on boards, rails, balusters and stairs

Porches and painted railings on older houses

Of the 13,080 housing units counted in town, 9,099 were built before 1980. A porch floor, railing or set of stairs that has been painted for decades on a pre-1978 house may have lead in its lower layers, so scraping or sanding it falls under the EPA's lead-safe rule. That means ground covers, no dry power sanding without HEPA collection, and careful cleanup of chips from the yard. Our lead-safe painting page explains the process.

If the siding and trim are due as well, the exterior painting page for Randolph covers the rest of the house. Coatings need dry wood and temperatures above the label minimum overnight; our post on deck stain and New England winters covers the timing.