Deck Painting & staining serving Millis and Metro West MA.

Water is the main enemy of a deck finish, and Millis has a lot of it close by. A 2019 climate-resilience report prepared for the town by the Metropolitan Area Planning Council says the Charles River makes up one-third of the town boundary and that water bodies and wetlands cover 28% of its area.

That doesn't mean every yard is wet, but a deck built low over damp or poorly drained ground dries slowly from underneath, and that moisture works its way into the boards, the stain and the framing.

Shade, leaves and mildew

The same report puts tree canopy at nearly 60% of the town. Under a canopy, deck boards stay damp after rain and dew, collect leaves and pollen in the gaps, and grow mildew and algae that make them slick.

A few habits do more than any stain to protect a shaded deck: blowing out the gaps between boards each fall, keeping planters and mats off the surface so wood can dry, and trimming limbs to let sun reach the floor for part of the day. When it's time to recoat, a cleaner that kills mildew and a stain with a mildewcide are worth specifying.

What the boards are made of

Census figures show 67.8% of the town's housing units are single-family detached and another 10.2% are single-family attached. If your home is attached and part of an association, check the rules on deck colors and who maintains the structure before choosing a product.

• Pressure-treated pine: the standard for backyard decks; new lumber should dry until water soaks in rather than beading before the first coat
• Cedar: naturally rot-resistant but grays quickly in sun; a penetrating oil or semi-transparent stain holds the color
• Painted porch floors: usually fir or pine tongue-and-groove, finished with porch-and-floor enamel; on older houses the existing paint may contain lead
• Composite and PVC: cleaned rather than stained, though products exist for recoloring faded composite

Stain, solid color or paint

A penetrating semi-transparent stain wears away slowly and can be refreshed with a cleaning and a new coat. Solid stain and paint form a film that covers worn or mismatched wood, but water trapped below a film on a damp deck pushes it off as peeling. On a low, shaded deck, a penetrating finish on the walking surface and a solid color on rails and balusters is a combination worth considering. Our paint vs. stain comparison goes through the trade-offs.

On a house built before 1978, a painted porch floor or railing may have lead in the older coats. Scraping or sanding it is regulated work; see our lead-safe painting page.

Picking the right weather

Early spring boards are often still saturated from snowmelt and rain, so late spring through early fall, after a stretch of dry days, is a better target for staining. Stain labels list a minimum temperature and a rain-free period after application; both matter more than the calendar date. The blog post on deck stain through a New England winter covers how finishes wear over the cold months, and exterior painting in Millis covers the house itself.