Here's the industry's open secret: the paint on two competing bids is often identical. The gap between a finish that lasts four years and one that lasts twelve lives almost entirely in the days before anyone opens a can. Prep isn't a step of the paint job — prep is the paint job.
Wash, then wash again
Coastal homes wear an invisible coat of salt, mildew spores, and airborne grime, and paint applied over it bonds to the dirt, not the house. Proper prep starts with a real wash — cleaner chosen for the surface, mildewcide where the shade side needs it, then full rinse and dry time. On the Monterey Bay this step matters more than anywhere inland, because salt is hygroscopic: it keeps pulling moisture into the film forever if it's sealed in.
Scrape, sand, and feather
Every square inch of failing paint has to come off — not just what falls off easily. Edges of intact paint get feather-sanded so old and new film meet without a visible ledge. Glossy surfaces get scuffed so primer can bite. This is the slowest, least glamorous work on the project, and it's precisely the line item lowball bids quietly delete — a shortcut you can't see on day one and can't miss by year three.
Repair, prime, and seal the water out
Then the surgery: cracked boards replaced, soft wood consolidated or cut out, nail heads set and spot-primed, every joint re-caulked with a sealant that flexes through fog-swollen mornings and sun-baked afternoons. Bare wood gets primer matched to the species and exposure — tannin-blocking on redwood and cedar, bonding primer over old enamels. Primer is not optional white paint; it's the adhesive layer the whole system stands on.
How to buy prep like a professional
You can't supervise every hour of sanding, but you can buy prep the smart way: insist the estimate name the prep steps — wash method, scraping standard, repairs included, caulk and primer products by name. As we put it in our estimates guide, vague prep language is the most reliable tell of a thin bid. A contractor proud of their prep will happily put it in writing. We always do.
