You notice it first along the edge, where the corner meets the soffit or near the bottom of a shaded wall. A hairline crack that wasn’t there last month, maybe a blister forming under the paint, or a sandy feel where the finish used to be smooth.

That’s the Florida weather working its way into the plaster around your home.

How Florida Weather Impacts Plaster: Longevity and Maintenance Tips

Sun Doesn’t Just Fade Paint, It Bakes the Surface

Direct summer sun in Florida isn’t just hot; it’s relentless, and west-facing walls take the worst of it. On stucco or exterior plaster, that means daily expansion and contraction. The material swells in the heat, shrinks overnight, and repeats until fine cracks start to spread.

White plaster might hold up longer, especially if it’s been sealed well. Dark-colored finishes absorb more heat, and over time, even a well-done finish will start to craze with those spiderweb cracks that don’t go all the way through but still leave the surface weak.

Inside, that heat changes the way a room holds moisture. Plaster walls in a sun-facing room can dry out too quickly, especially if the AC is on full blast. That kind of dryness can cause dusting, where the surface starts to powder off when touched.

Humidity Seeps in Even When the Walls Look Dry

Florida’s humidity doesn’t stop at ruining the surface of your plaster. It lingers in the air, gets pulled into walls through windows, vents, and cracks in the paint layer. When moisture hits the lath or backing under plaster, that’s when problems start.

In older homes with wood lath, you might notice plaster beginning to bulge in places. That’s the moisture warping the lath underneath or breaking down the bond between the plaster and its base. It might hold for a while, but you’ll hear it before you see it: a dull, hollow sound when you knock near the crack.

Cement-based plaster doesn’t crumble easily, but it absorbs moisture like a sponge. If your exterior hasn’t been resealed in the last five years, it’s probably letting in more than you think, especially after hurricane season.

Storms Bring More Than Just Water

It’s not just the rain, it’s the pressure changes, and the way wind pushes against walls for hours, or the way everything gets soaked, then baked the next day under a blistering 95 degrees. Even good plaster starts to show signs of decay in those conditions.

After a major storm, run your hand along the inside corners of rooms on exterior walls. If they feel gritty or soft, the finish coat might be starting to separate. If you see dark patches near the baseboards that weren’t there before, water has found a way in.

What You Can Do to Keep Plaster Holding Up

You don’t need to wait until there’s visible damage. Start by watching what the seasons do to your home. Look at the walls in June, then again in late August. That’s when the real damage happens, when moisture and heat combine and stick around.

Reseal the exterior every five years if you’re close to the coast, and every seven if you’re further inland. Use a breathable masonry sealer, not paint. You want moisture to escape, not get trapped.

Inside, keep a stable temperature. Ceiling fans circulating air keep walls from staying damp. If your AC pulls too much moisture from the room, a small humidifier in the winter months can keep the plaster from getting brittle. If you’re seeing fine cracks or surface wear, lime wash is a better fix than latex paint; it binds with the plaster and lets it breathe. Paint just traps the problem underneath.

Florida Weather Will Test Every Surface—Plaster Included

If a crack keeps reopening, or you tap a wall and it sounds hollow over a large area, it’s time to call in the pros, especially if the home was built before 1970 and still has its original walls. Plaster failure doesn’t always lead to a full replacement, but the longer you wait, the more it costs to stabilize.

It’s not the kind of damage you notice right away. It sneaks in subtly through heat, salt air, and weeks of high humidity. The trick is staying ahead of it.

United Plastering in Florida

Specializing in interior and exterior finishes including: Stucco, hardcoat, drywall, plaster, cornice, metal framing, and decorative work. Schedule a Plaster Inspection with United Plastering
At United Plastering, we specialize in protecting and restoring plaster in Florida’s most demanding climates. Whether you’re dealing with surface cracks, moisture damage, or full exterior restoration, our team has the expertise and tools to preserve the integrity and beauty of your walls.

Contact us today for an inspection or maintenance consultation—and let’s keep your plaster looking flawless, no matter what Florida throws at it.