What Florida Sun, Salt and Humidity Do to Exterior Paint, and the Prep That Slows It Down

Walk down any street in Palm Beach County and you can read the age of each house's paint from the curb. Chalky stucco, hairline cracks along the trim, peeling fascia boards, a green film creeping up the shady side of the garage. None of that happens because the homeowner picked a bad color. It happens because the house sits outdoors in sun, salt air and humidity, and the coating on it is doing a hard job. If you're thinking about repainting the outside of your home, it helps to know what that coating is up against and what a painter does to give a new one its best chance.

What the weather is actually doing

Three things wear on an exterior finish here, and they work together.

• Sun: strong ultraviolet light breaks down the binder that holds pigment in paint. The color fades, the surface turns powdery, and the coating gets thinner than it looks.
• Humidity: moisture sits on and in surfaces for much of the year. Mildew grows on it, and any gap in the coating lets water into stucco, wood and trim.
• Coastal salt: near the water, salt in the air settles on walls and fixtures. If it isn't washed off before painting, it can interfere with how new paint bonds.

A finish that looks tired is usually telling you one of those three has been winning for a while.

Washing comes first, and it's not just for looks

Paint sticks to clean, sound surfaces. It does not stick well to mildew, chalk, dirt or old salt. So the first step on a proper exterior job is a thorough pressure wash. That clears the film and the growth that has built up, and it shows the painter what the surface really looks like underneath. Walls then need time to dry before anything else happens. A surface that is still damp when primer goes on is a surface that will give trouble later.

Scrape, sand, caulk, repair

Once the walls are clean and dry, the real inspection starts. Loose and flaking paint gets scraped back to something solid, because new paint over old paint that's already letting go will simply let go with it. Rough edges are sanded so the old and new surfaces blend. Gaps around windows, doors and trim are caulked, since an open joint is where water finds its way behind the coating.

Then come the repairs. Cracked stucco is patched. Soft or rotted wood on fascia, soffits and trim is repaired or replaced, not painted over. Painting over rot hides it for a season while it keeps spreading underneath. It's the least exciting stage of the job and the one that decides how long the finish will last.

Prime, then use a coating built for the climate

Bare patches, repaired areas and stained spots get primed so the finish coat has an even base and takes up color the same way everywhere. After that, the coating itself matters. Premium exterior coatings are made to flex with temperature swings, shed water and hold their color against sun.

Stucco, siding, trim, fascia, soffits, doors and shutters each take paint a little differently, so a good painter treats them as separate surfaces. Trim and doors usually get a sheen that wipes clean and resists the elements. Walls get a finish that breathes and hides small flaws. The color you choose is up to you; getting the right product on each surface is the painter's job.

Questions worth asking before you hire

• Is pressure washing part of the job, and how long will the walls dry before priming?
• What happens to damaged stucco and rotted wood: patched and replaced, or painted over?
• Which products go on the walls, the trim and the doors, and why?
• Does the written scope list the sequence, the materials and the timeline?

How Brothers Painting handles it

Brothers Painting is a family-operated, licensed and insured painting contractor in West Palm Beach, with 15 years behind it and a 4.8 rating from 18 Google reviews. For exterior work the sequence is the one above: pressure wash, scrape, sand, caulk, repair, prime, then premium coatings. The estimate is free and done on site, it comes with a written scope, and once the team starts your job, they stay until it's complete.

More on this work is at /exterior-home-painting. To talk through your house, call (561) 633-3047 or request a free estimate.