On a proper exterior repaint, we spend roughly four hours preparing each surface for every one hour of actual paint application. Homeowners are sometimes surprised. Here's why it has to be that way.

Prep is what paint adheres to

Paint doesn't bond to chalking, mildew, loose wood fibers, or old caulk. It needs a clean, sanded, sealed substrate. Every shortcut on prep is a shortcut on how long the paint will actually stay attached.

The prep sequence

  • Wash. Soft-wash or pressure-wash with mildew killer.
  • Scrape. Remove any paint not firmly attached.
  • Sand. Feather the edges of scraped areas and scuff glossy surfaces.
  • Spot prime. Oil-bond on bare wood, stain-block on water stains, bonding on slick substrates.
  • Caulk. Every joint inspected; failing caulk removed and replaced with siliconized acrylic.
  • Fill. Nail holes, gouges, small defects filled and sanded smooth.
  • Mask. Plastic, tape, and drop cloths everywhere paint could land.

The 80/20

On a 5-day exterior repaint, days 1–3 are prep. Painting is days 4–5. On a 5-day interior repaint, day 1 is often pure prep. That ratio is the single biggest difference between a finish that photographs well for a month and one that still looks sharp in 2030.

What you can check

On any estimate you're considering, ask the painter to walk you through prep by surface type. If they skip to color selection, keep shopping.