Drying is the quiet half of painting
Paint goes on in minutes and spends hours, sometimes days, turning from a wet film into a hard one. Water-based paint dries by giving its water to the air; then the film cures as it hardens. Warm, moving air speeds that up. Cool, still, damp air slows it down. Most of what follows is about giving a coat the conditions it needs, outside and in.
The Kelso-Longview counts
In an average year at Kelso-Longview, NOAA counts about 1 hours with the wet-bulb temperature above 73°F and about 72 hours above 67°F.
A wet-bulb reading folds heat and humidity into one number. These are small counts of warm, humid hours at the station. On their own they say nothing about rain, fog or cool damp days, and this page doesn't fill that gap with guesses. For an exterior job, the deciding questions are the ones printed on every paint label: how warm the air and the surface are, whether the siding is dry, and whether dew or rain will reach the coat before it sets.
Moisture in the wood
Siding and trim hold water after a wet spell, and paint applied over damp wood is a common cause of blistering and peeling later. Many painters check boards with a moisture meter before priming, and wait for the wood to dry out after washing. Questions worth asking:
- How long will the house dry after washing, and how do you decide it's ready?
- Will you meter the siding before primer goes on?
- How will you treat mildew before painting over the area?
Mildew should be cleaned off and killed, not covered; it grows back through a fresh coat. Our exterior painting page covers washing and priming.
Washington's registration rule
Washington requires all construction contractors to register with the Department of Labor & Industries, and painting is one of the specialties L&I registers; a specialty contractor may only do work in the specialty it is registered in.
That is the department's own wording, and this page reads nothing further into it. You can ask a painter which specialty they are registered in with L&I and keep that answer with the proposal. If your job also involves something other than painting, such as replacing rotted trim before paint, ask who will do that part. We pass your request to an independent painter and don't look anything up on your behalf.
Lead-safe work
EPA runs the RRP program in states it has not authorized; Washington appears on EPA's list of the states that run their own EPA-authorized programs. Where old paint will be scraped or sanded, ask the painter how dust and chips will be contained and cleaned up, and look for that step in the written proposal.
Inside: ventilation and patience
Interior paint follows the same chemistry. In a closed house on a cool day, walls take longer to dry between coats, and the finish takes longer to harden enough for furniture, pictures and cleaning. Good practice indoors:
- keep rooms being painted heated to a level the label allows;
- open windows or run fans when the weather allows, to move air;
- respect the recoat time on the can even if the surface feels dry;
- wait before hanging things on fresh paint or pushing furniture back against it.
Cabinet and trim enamels take the longest to cure. See cabinet painting and refinishing and paint sheens and finishes.
Planning the job
- List the rooms or sides of the house that are in, and the ones that aren't.
- Ask for a written scope with prep, primer, coats and products named.
- Agree on how weather delays are handled for outside work.
- Agree on who repairs any rot found under old paint, and how it's priced.
- Ask for the product data sheets, so you can see the recoat and cure times yourself.