When exterior paint fails in Massachusetts, the failure mode tells you why. Peeling looks different from alligatoring, which looks different from blistering. Reading the pattern points to the cause — and the right fix.
1. Peeling near the ground line
What you see: Paint flaking off in sheets on the lower 18–24 inches of siding, often worst where snow piles up.
Cause: Moisture wicking up through the substrate. Snowmelt, sprinklers, and rain splash hit this zone hardest. If the bottom edge of siding wasn't primed before installation (common pre-1990 construction), water enters from below.
Fix: Scrape to sound substrate, oil-bond prime the bare wood (Cabot Problem-Solver or equivalent), reseal the bottom edge with paintable caulk, then top coat. Don't paint over peeling paint — it'll fail in the same spot.
2. Alligatoring
What you see: Cracking pattern resembling alligator skin — small interconnected cracks across a paint surface.
Cause: Successive layers of paint with incompatible flexibility. Old oil-based paint under new latex is the classic example. The latex moves with temperature; the oil doesn't. The latex cracks.
Fix: The cracked layer has to come off — heat-strip, chemical-strip, or sand to sound substrate. Then bonding primer before the new coat. There's no shortcut. Painting over alligatoring guarantees you'll see it again in 2 years.
3. Blistering
What you see: Small bubbles in the paint, raised and often filled with moisture or air.
Cause: Painting in direct sun or on a hot surface (solvent flash-evaporated and trapped vapor under the film). Or moisture trapped in the substrate at paint time.
Fix: Open the blisters, scrape, sand, prime, repaint. Schedule the repaint for early morning or shaded side of the house, never the south wall at 2pm in July.
4. Chalking
What you see: White powder that rubs off on your hand when you touch the siding. Worst on south- and west-facing walls.
Cause: UV degradation of the paint's binder. The pigment is held together by a resin that breaks down over time. When the resin fails, pigment releases as powder.
Fix: Power-wash thoroughly, scrub south walls with a stiff brush + TSP substitute, prime with a chalk-binding primer (XIM Stix or Behr Drylok), then top coat. Painting straight over chalking guarantees coat adhesion failure.
5. Mildew on north/shaded walls
What you see: Dark green-black spots in shadowed areas. Often mistaken for dirt — but it doesn't rinse with water alone.
Cause: Mildew spores feed on paint surfactants in humid microclimates. The shade-side of MA homes near woods or wet yards is the perfect environment.
Fix: Soft-wash with mildewcide solution (sodium hypochlorite at 4%), let it dwell, rinse thoroughly. Then prime with a mildew-resistant primer and top with paint formulated with mildewcide additives (most premium exteriors include it). Don't skip the wash — paint over mildew traps it and it grows through.
The pattern that tells you something else is wrong
If you see two or more of these failures on the same elevation, the substrate has a deeper problem — usually moisture entry through the wall assembly. Address the building envelope (caulking, flashing, gutters, grading) before repainting. A new paint job over an unfixed moisture problem is a year-2 disappointment. See our exterior painting overview for our standard process, or our when to repaint guide.