Roof, gutters & exterior

Caulking gaps around exterior trim or windows

Cracked or missing caulk around windows, doors, and trim lets water and air behind the siding, and is one of the easiest and most valuable exterior fixes.

Difficulty
Easy
Time
1–3 hours
DIY cost
$10–$40
Pro cost
$150–$400

Symptoms

  • Visible gaps or cracked caulk lines around window and door trim
  • Drafts felt near windows in winter
  • Water staining just below a trim joint

Likely causes

  • CommonAged or dried-out caulkExterior caulk typically lasts 5–10 years before it cracks and needs replacing.
  • PossibleBuilding movement opening small gapsNormal seasonal expansion and contraction can widen joints over time.
  • PossibleWrong caulk type used originallyInterior-grade or low-flexibility caulk fails faster outdoors.

What to do

  1. Inspect all window, door, and trim joints for cracked, shrunk, or missing caulk.
  2. Remove old, failing caulk with a scraper or caulk removal tool.
  3. Clean and dry the joint fully before applying new caulk so it adheres properly.
  4. Apply a paintable, exterior-grade, flexible sealant (like siliconized acrylic or polyurethane) in a continuous bead.
  5. Smooth the bead with a wet finger or caulk tool for a clean, water-shedding profile.
  6. Let it cure per label instructions before painting if needed.
  7. Recheck caulking every couple of years, especially on the sunniest side of the house where it degrades fastest.

Tools and parts

  • Caulking gun
  • Caulk removal tool or scraper
  • Rag
Exterior paintable caulkSearch: “exterior window and trim caulk”

When to call a pro

Call a painting or handyman service for whole-house recaulking if you have many windows or limited time.

Safety

Use caution

Use a stable ladder for second-story windows and trim.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.