Seal hairline cracks with paintable caulk

Run a thin bead of paintable acrylic latex caulk along hairline cracks where walls meet trim, ceilings, or corners. Smooth the bead with a wet finger and let it dry. Paint over it once cured.

Why It Works

Caulk remains flexible after curing, so it absorbs the seasonal expansion and contraction that causes cracks to reopen. Rigid spackle in these joints tends to crack again within months.

Tips

• Use paintable acrylic latex caulk, not silicone (silicone repels paint)
• Cut the caulk tube tip at a small angle for a thin, controlled bead
• Smooth the bead immediately with a wet finger — caulk skins over quickly
• Best for cracks along trim edges, ceiling lines, and corner joints where walls flex
• Not suitable for filling holes — caulk is for linear cracks and gaps only