Best Paint for Coastal Homes: Salt Air, Sun and Humidity

Quick answer: The best paint for a coastal home is a premium 100 percent acrylic exterior latex with a mildew inhibitor, applied over a surface that has been washed free of salt and fully dried, with every joint caulked and every bare spot primed. On the coast, the prep, the primer and the metal details matter as much as the paint, and a regular wash keeps the finish going longer.

Salt air, sun, wind driven rain and humidity all work on a coastal house at once. No paint makes a seaside home maintenance free. What you can do is choose a paint that handles moisture and sun well, prepare the surface so salt is not trapped under the new film, and detail the house so water and corrosion do not push the paint off from behind. This guide covers all three, and it applies to hot, humid inland climates as well, because mildew and moisture are the same problems there.

Why the coast is hard on paint

• Salt. Salt deposits on every surface facing the water. Paint applied over salt does not bond well, and salt draws moisture to the surface.
• Corrosion. FEMA says in its coastal construction guide (Home Builders Guide to Coastal Construction, Technical Fact Sheet 8) that coastal environments encourage metal corrosion, and that corrosion is most pronounced on homes within about 3,000 feet of the ocean. Rusting nails, screws and hardware stain paint and lift it from below.
• Moisture and decay. The same FEMA fact sheet notes that end grain cuts absorb moisture up to 30 times faster than the sides of a wood member. Unsealed ends are where coastal paint often fails first.
• Sun and wind. Open shorelines get strong sun and wind blown sand, which fade and wear the finish on the most exposed walls.
• Mildew. Sherwin-Williams notes in its article on mildew that mildew forms on surfaces that stay damp or get little direct sun. Humid coastal air gives it plenty of both.

What type of paint to use

A premium 100 percent acrylic exterior latex is the standard choice for coastal homes, for these reasons:

• Acrylic film stays flexible, so it moves with wood and siding through heat, cold and wetting without cracking.
• It holds color and resists chalking in strong sun better than lower grade paints.
• It lets some moisture vapor escape, which helps on wood.
• Premium lines include mildew inhibitors. Sherwin-Williams recommends using a product that contains agents that inhibit mildew growth on the paint film, while its exterior troubleshooting FAQ is honest that mildew can eventually return on any paint under the right conditions.

Some paint makers sell lines marketed for coastal or harsh climates. They can be good choices, but read the data sheet rather than the label: what you want is a 100 percent acrylic binder, a mildew inhibitor and the right sheen for the surface. Treat any named brand as an example rather than the single best paint for the beach.

Sheen and color by the sea

• Siding and walls: satin or low luster usually works best. It sheds salt and dirt better than flat and is easier to rinse clean. See the paint sheen guide for the full range.
• Trim, doors and railings: satin or semi-gloss. The harder film stands up to wind blown sand and frequent cleaning.
• Color: lighter colors reflect more sun and run cooler on south and west walls, and they show fading less. Deep, saturated colors fade fastest in strong sun. Picking a palette that suits the setting is covered in how to choose exterior paint colors.

Prep: get the salt off first

1. Wash every surface. Rinse the house with fresh water and a suitable cleaner to remove salt, dirt and chalk. Work from the top down. Engineered wood siding should be washed by hand, not pressure washed, as covered in best paint for LP SmartSide siding.
2. Treat mildew separately. Sherwin-Williams recommends a solution of one part liquid bleach to three parts water, scrubbed on and left for about 10 minutes, then rinsed thoroughly. It warns never to add ammonia or detergent to the bleach solution, and to wear eye protection, gloves and protective clothing.
3. Let it dry completely. Coastal humidity slows drying. Give wood siding enough time that it is dry inside, not just on the surface.
4. Scrape and sand any loose or peeling paint and feather the edges.
5. Prime every bare spot, with extra attention to cut ends and the bottom edges of siding and trim.
6. Caulk joints at trim, corners and openings with a paintable exterior sealant, so wind driven rain cannot get behind the paint. See how to caulk before painting.

Paint as soon as practical after washing. A house left for days near the water starts collecting salt again. If you are pricing this prep as a contractor, how to price pressure washing before painting covers the wash step.

Metal details: fasteners, railings and hardware

On the coast, rust is often what spoils a paint job, not the paint. FEMA recommends hot-dipped galvanized or stainless steel hardware, and warns against joining dissimilar metals such as copper and steel, which corrode where they meet.

• Rust streaks from nails. Sink and spot prime rusting nail heads, or replace them with corrosion resistant fasteners, before painting. Painting over them without treatment brings the streaks back.
• Galvanized railings and hardware. Use an acrylic paint. Sherwin-Williams explains that oil or alkyd paint reacts with the zinc on galvanized metal and peels. The full method is in how to paint exterior railings.
• Steel and wrought iron. Remove loose rust and prime with a rust inhibitive primer before the topcoat. More in best paint for metal.

Surface by surface on a coastal house

Timing and weather on the coast

• Paint when surfaces are dry and the forecast is clear for the cure time on the label.
• Sherwin-Williams advises avoiding painting on hot, humid days with significantly cooler evening temperatures, because dew can form on the fresh film.
• Start after the morning dew has dried, and stop early enough for the paint to set before evening moisture returns.
• Avoid windy days, which blow sand and salt onto wet paint.

More detail on temperature, humidity and dew is in best weather conditions for exterior painting.

Maintenance that makes coastal paint last

The most useful thing a coastal homeowner can do is rinse the house regularly. Gentle washing removes salt and mildew before they damage the film, and it costs far less than an early repaint. Check caulk and the bottom edges of siding each year, touch up chips before rust or moisture gets in, and repaint the most exposed walls when they need it rather than waiting for the whole house. How long exterior paint typically lasts, and the signs a repaint is due, are covered in how long does exterior paint last.

If the home was built before 1978, the paint may contain lead. Contractors working on it must follow the EPA Renovation, Repair and Painting rule.

Frequently asked questions

What is the best exterior paint for a coastal home?

A premium 100 percent acrylic exterior latex with a mildew inhibitor, in a satin or low luster sheen for walls. The paint matters, but washing off salt, priming bare spots and caulking joints matter just as much.

How do you remove salt before painting?

Wash every surface with fresh water and a suitable cleaner, working from the top down, then let everything dry completely. Paint soon afterward, because salt builds up again on a house near the water.

Is elastomeric paint good for coastal homes?

On stucco and masonry it can be, because it bridges hairline cracks and resists wind driven rain. It is not usually the right choice on wood siding, which needs a coating that lets moisture escape.

How do I stop mildew on a coastal house?

Clean existing mildew with a diluted bleach solution, rinse and dry, then use a paint with a mildew inhibitor. Regular washing is still needed, because mildew can return on any paint in damp conditions.

Why do nails rust through the paint near the beach?

Coastal air speeds up corrosion. Fasteners that are not hot-dipped galvanized or stainless rust and stain the paint. Treat or replace them and spot prime before painting, or the streaks return.

What color paint lasts longest on a beach house?

Lighter colors generally show fading less and stay cooler in strong sun. Deep, saturated colors fade fastest on south and west facing walls.