How to Prep Your Home for Exterior Painting

Prep determines how long an exterior paint job actually lasts. Paint sticks to clean, sound, dry surfaces, and falls off everything else. A premium $90 gallon of Sherwin Emerald on bad prep will fail in 18 months. A mid-grade paint on great prep will last 10 years. This guide covers what your painter should handle, what you can do to make the job go faster, and what good prep actually looks like in Portland's wet climate.

What homeowners can do before the painters arrive

None of this is required. But every hour you do is an hour your painter is not billing you for.

• Trim back vegetation. Anything within 3 feet of the siding should be pruned back so the painter can reach the wall without fighting through shrubs. Pay attention to climbing roses, ivy, and lilac.
• Move outdoor furniture and decor. Patio sets, planters, grills, hose reels, garden ornaments. Move them at least 6 feet from the house.
• Take down hanging items. Wreaths, address numbers if they are easily removable, exterior light covers if you want them painted around (or removed).
• Clear gutters and downspouts. Especially if they will be painted. Painters do not clean gutters.
• Park cars away from the house. Driveway parking risks overspray and drop cloths in the way.
• Plan for pets. Containment plastic and ladders are not pet-friendly. Plan to keep dogs and cats indoors during work hours.

What good prep looks like (painter's side)

A proper Portland exterior prep sequence looks like this:

1. Wash. Pressure wash the entire structure (typically 1,500-2,500 PSI for siding; lower for older wood). Removes dirt, mildew, chalk, loose paint. Soap applied first if mildew is present. Surfaces need to dry for 24-48 hours after washing before any other work.
2. Scrape failed paint. Any peeling, flaking, bubbled, or alligatored paint comes off. Hand scrapers, carbide scrapers, and (on pre-1978 homes) HEPA-attached sanders. The goal is sound paint at the edges; the painter is not necessarily stripping back to bare wood unless the paint is failing throughout.
3. Sand transitions. Where scraped paint meets sound paint, sand the edge smooth so the new coat does not show a ridge. Feather-sanding is mandatory on visible elevations.
4. Carpentry repair. Soft wood from rot or water damage gets cut out and replaced. Common Portland spots: bottom of door trim, lower corners of window casings, fascia behind failing gutters, anywhere a downspout has dripped onto siding. Wood epoxy is fine for cosmetic fill; structural rot needs replacement.
5. Caulk. All seams between siding, trim, windows, and doors get sealed with paintable exterior caulk (typically siliconized acrylic or polyurethane). Old failed caulk is removed and replaced, not painted over.
6. Spot prime. Bare wood gets an oil-based or bonding primer. Tannin-bleeding woods (cedar, redwood) need a stain-blocking primer to prevent brown bleed-through on light-colored topcoats.
7. Mask. Windows, light fixtures, deck boards, A/C units, hose bibs. Plastic and tape on everything that should not be painted.
8. Paint. Two full coats, brush or roller for cut lines, spray on broad surfaces back-brushed for adhesion. Cured 4 hours minimum between coats.

Portland-specific failure points to watch for

Portland's wet climate creates predictable trouble spots that cheap prep will skip:

• North and east elevations hold moisture longer and grow more mildew. They almost always need a soap wash, not just a water rinse.
• Cedar siding bleeds tannins for years. Skipping stain-blocking primer guarantees brown patches by year two.
• Behind downspouts where gutters have overflowed: rotten fascia is the rule, not the exception, on Portland homes older than 30 years.
• Ground-level skirt boards wick moisture from soil splash. Need real prep including a moisture-tolerant primer at the bottom course.
• South-facing window sashes get sun-baked and the existing paint is often chalky. Solid scrape and prime, not just topcoat.

What "two coats" really means

Some quotes will say "two coats" but in practice the painter is doing one full coat plus touch-up on thin spots. That is not two coats. A real two-coat job is two full applications across the entire substrate, each at the manufacturer's recommended mil thickness. Ask whether the second coat is full-surface or just touch-up, and get the answer in writing.

On dark colors over light substrates (or vice versa), a third coat may be needed for full coverage. Reputable painters will tell you that up front and price accordingly.

How long good prep adds to the timeline

On a typical 2,000 sq ft two-story Portland home, the prep stages take 2 to 4 days before any paint goes on. Painting itself is 2 to 3 more days. Total: 4 to 7 days for the job, plus 1 to 2 weather buffer days. A painter quoting a one-day exterior job is either skipping prep or quoting only a touch-up.

Ready to get a quote with proper prep included? Start a free quote request and we will match you with vetted Portland painters who can walk you through their prep approach.

Common questions