Paint on a house that freezes and thaws
The coating on an exterior wall is thin, and the wood or fiber cement under it moves. It swells when wet, shrinks when dry, and any water trapped in a crack expands when it freezes. A paint job that lasts has to keep water out of the places where that movement is worst. On a Barnstable house, that's where most of the preparation time should go.
NOAA's Otis ANGB station
NOAA's engineering weather data comes from Otis ANGB, about 12 miles west of Barnstable on the Upper Cape. For that station it lists about 54 freeze-thaw cycles in an average year, a 50-year basic wind speed of 120 mph (3-second gust at 33 feet) and a 100-year rainfall rate of 2.5 inches per hour. These are the Otis ANGB station's figures, as the card below gives them, not readings taken in town.
Where freeze-thaw does its damage
About 54 cycles a year means many chances for water in a crack to freeze and pry it wider. The usual places:
- End grain of siding boards, trim and shingles, which drinks water far faster than the face;
- butt joints where two boards meet;
- window sills and the bottom rail of sashes, where water sits;
- the lowest course of siding, close to splash and snow;
- nail heads that have rusted or worked loose.
A good painter primes exposed end grain wherever they can reach it, renews caulk at joints that are meant to be sealed, and leaves open the gaps meant to drain.
Wind, rain and the paint film
Wind drives rain sideways, under laps and into joints that stay dry in calmer weather. That's why the details above matter more than the number of finish coats. Ask the painter to walk the house with you and point out every joint they'll seal and every spot they'll leave open.
Scraping and sanding to a sound edge
Loose paint has to come off. The standard is a firm edge: scrape until the remaining paint can't be lifted with the scraper, then feather the edges with sandpaper so the step doesn't telegraph through the new coat. Bare wood exposed this way should be primed quickly, before dew or rain gets into it. Our exterior painting page goes through the full sequence.
When the paint may contain lead
Scraping and sanding old paint makes dust, and in homes built before 1978 that paint may contain lead. EPA's card on this page sets out the federal Renovation, Repair and Painting Rule: paid work that disturbs paint in pre-1978 homes, childcare facilities and preschools calls for RRP certification for the firm, sole proprietorships included, with workers trained in lead-safe work practices. A second EPA card lists the states that run their own EPA-authorized programs, and Massachusetts is one of them. You can ask the painter whether the firm holds RRP certification, and how they'll contain chips and dust on the ground and on the wind.
Timing the job
Paint labels set minimum temperatures for the air and the surface, often for several hours after the coat goes on. Ask the painter which products they'll use, what their minimums are, and how they'll plan the work so that coats aren't exposed to a freeze before they've set.
A Barnstable checklist for the proposal
- every surface included, from siding to porch ceilings;
- how end grain, sills and joints will be treated;
- scraping standard, and how bare wood will be primed;
- lead-safe practices if the house predates 1978;
- products, colors and sheens by name.
The pricing guide explains why the preparation lines change the price more than the paint does.