When homeowners get three exterior painting bids that range from $3,200 to $6,000 for the same house, the variance isn't the paint. Premium paint costs $60–$90 a gallon; the difference in materials between a low bid and a high bid on a 2,000 SF house is maybe $400. The rest of the gap is labor — and specifically, prep labor.
Prep is everything that happens before paint touches the surface: scraping loose paint back to a firm edge, sanding feathered edges smooth, wire-brushing rust from metal surfaces, recaulking every joint around windows, doors, trim, and flashing, repairing gouged or rotted wood, and applying primer to every bare surface. On a well-weathered Portland Craftsman, this can take two full days before a brush comes out. A crew that skips or rushes it can start applying paint on day one.
What gets cut on a low bid
We have repainted dozens of Portland homes where a previous contractor left behind legible evidence of what they skipped. The most common: feathered edges not sanded (paint edges show through the new coat within months), caulk gaps left open (water infiltrates and blisters the paint from behind), bare wood primed with diluted primer or not primed at all (the finish coat is directly on raw wood, which soaks it up unevenly and provides almost no adhesion), and nail heads left unpainted and unspotted (rust bleeds through within a year).
Each of these failures is repairable, but each one requires stripping back to a solid edge and starting over. The homeowner pays twice.
How to read a bid for prep
A legitimate itemized bid lists prep work separately from painting — scraping, caulk, spot prime, full prime where bare, repairs. If a bid is a single line item (e.g., "paint exterior — $3,400"), there is no accountability for what prep is included. Ask the contractor to break out hours spent on prep versus finish coat application. A well-prepped exterior job on a 2,000 SF Portland home should involve 16 to 24 hours of prep labor. If the math on their hourly rate doesn't support that, the prep isn't in the bid.
The cheap bid is not always wrong. Some houses are in very good condition and genuinely need less prep. But on a home that hasn't been painted in 10+ years, a bid that comes in 40% below the next-lowest should be asked to defend its prep scope in writing before you sign.