The Flint/Bishop figures
NOAA's engineering weather data for Flint/Bishop lists a 50-year basic wind speed of 90 mph (3-second gust at 33 feet), a 100-year rainfall rate of 2.8 inches per hour and about 61 freeze-thaw cycles in an average year.
Those are the station's numbers as NOAA publishes them, not measurements at your home. The wind and rainfall values are design figures for rare events. The freeze-thaw count is the everyday one: about 61 times in an average year, the air at the station crosses freezing, and moisture trapped in a cracked coating can turn to ice, expand and pry the film further open.
Siding decides the job
Ask most people what drives a paint bid and they'll say square footage. For an exterior, the siding material matters just as much. Each one takes paint differently, needs different preparation and fails in its own way. Knowing which one you have makes it easier to judge whether a proposal fits the house.
Aluminum siding
Old aluminum siding often has a factory finish that has turned chalky: rub it and your hand comes away colored. Paint over chalk doesn't hold. The usual approach is a thorough wash, sometimes with a cleaner made for the purpose, then a primer if the painter or the paint maker calls for one. Dents and loose panels are worth fixing before paint, because a fresh coat makes them more noticeable, not less.
Vinyl siding
Vinyl can be painted, but color matters. A darker color than the original can absorb enough sun to make some vinyl warp or buckle. Many paint makers sell colors and products meant for vinyl, and some siding makers say what they allow. Ask the painter which product and color range they'll use, and whether the siding maker's guidance has been checked against it.
Wood siding and trim
Wood is the material most affected by the freeze-thaw cycle, because it soaks up water at its ends and through any break in the film. Preparation is where the money goes:
- scraping loose paint back to a firm edge;
- sanding the edges so they don't show;
- replacing or repairing soft boards and trim before priming;
- priming bare wood and every repair;
- caulking joints that should be closed, while leaving the underside of each lap unsealed, since that seam lets moisture escape from behind the boards.
If the house was built before 1978, old paint layers may contain lead. The EPA explains the federal rule for paid work that disturbs paint in older homes on its lead program page. Ask the painter how they'd contain chips and dust during scraping.
Fiber cement
Fiber cement usually takes paint well once it's clean, and it's less prone to the swelling and shrinking that loosen paint on wood. Some boards came from the factory with a finish meant to be painted only after a certain point or only with certain products; ask the painter to check what the siding maker says.
Color and sheen on the outside
Sun and weather are hardest on dark, glossy colors on the sunniest walls. Lighter colors usually hold their look longer. Trim often gets a glossier finish than the body because it sheds water and wipes clean more easily. The sheen guide goes into the trade-offs.
Painters under the Occupational Code
The card below sets out, in the Legislature's own terms, where painting and decorating stands under the Occupational Code's residential maintenance and alteration trades. Whatever a firm's paperwork, what you're buying is defined by the signed scope. Ask for the siding type, the cleaning method, the primer, the number of coats and the product names to be written down.
More on exterior preparation is on our exterior painting page.