Why does stucco crack here?
Some cracking is normal — stucco is cement, it moves, and hairlines at the corners of windows and doors are where that movement concentrates. What is not normal is leaving them open near salt water.
Salt penetrates the crack, reaches the metal lath, and rusts it. Rust expands, which widens the crack from the inside. That is the mechanism behind the rust stains bleeding down a wall below a window, and by the time the stain is visible the repair is bigger than a patch.
What a proper stucco patch involves
The failure mode of a bad patch is a rectangle you can see from the street, in a slightly different colour and a slightly different texture. Avoiding that takes four things:
- Cut back to sound material — a patch over a delaminated edge fails at the same edge
- Treat or replace corroded lath rather than covering it
- Build back in layers with the correct mix, not one thick fill
- Match the finish texture — sand float, dash, lace and smooth all read differently in raking light
Should stucco be sealed or painted?
On the coast, elastomeric coatings on stucco dramatically outperform standard exterior paint, because they bridge hairline movement instead of cracking with it. The material costs more per gallon and the lifespan difference is measured in years.
The caveat matters: elastomeric traps moisture if it goes over a wall that is already wet, or over a crack that is still feeding water in behind. Repair first, dry, then coat. In that order it is the best product available for a Gulf Coast wall — in the wrong order it seals the problem in.
Where this comes up most
Older block-and-stucco housing stock in Fort Walton Beach and Pensacola cracks along the same hairlines every cycle, so patching before paint is what separates a repaint that lasts six years from one that opens again in two.
On condo and association buildings it is a reserve-study item rather than a repair: see HOA and community painting.
How long does a stucco repair need before it can be painted?
7 days minimum, and 14 is better. Fresh stucco is alkaline while it cures, and paint applied over it burns — the colour shifts and the film fails early. This is the single most common corner cut on a coastal repaint, because it is the one nobody can see being skipped.
The repair itself is quick by comparison: cutting back to sound material and building the patch in 2 or 3 layers is a half day for a typical window corner. It is the wait that has to be scheduled, which is why stucco repairs get booked ahead of the paint rather than discovered on the first morning of it.
On a whole elevation, allow 2 to 3 weeks from first repair to finished coat. On a 5 to 7 year coastal repaint cycle that is a rounding error, and it is the difference between a wall that lasts the cycle and one that opens up in year two.