How to Fix Cracks in Drywall
Thin cracks in a wall or ceiling, often near corners, door frames, or where a wall meets the ceiling.
DIY Cost
$10–$20
Typical Pro Cost
$100–$200
Tools Needed
- Utility knife
- 5-in-1 tool or putty knife
- Sanding sponge
Parts Needed
- Self-adhesive fiberglass mesh tape
- Joint compound (mud)
- Touch-up paint
⚠️ Safety Warnings
- Wear a dust mask when sanding dried joint compound, especially indoors with limited ventilation.
Step-by-Step Instructions
Widen the crack slightly
Run a utility knife along the crack to open it very slightly (a V-groove) — this gives the joint compound something to actually grip instead of just sitting on top of a hairline gap that will telegraph back through.
Clean out dust and debris
Brush or vacuum away any loose drywall dust from the widened crack so the compound bonds directly to solid material.
Apply mesh tape over the crack
Press self-adhesive fiberglass mesh tape directly over the full length of the crack — this is the step most DIY crack fixes skip, and skipping it is why the crack usually comes back within a year. The tape bridges the crack so future minor movement doesn't reopen it.
Apply joint compound over the tape
Using a putty knife, spread a thin, even layer of joint compound over the tape, feathering the edges a few inches out on both sides. Let it dry fully — usually overnight.
Sand and apply a second coat
Lightly sand the first coat, then apply a second, slightly wider coat to further feather the edges into the wall for an invisible transition. Let dry again.
Final sand, prime, and paint
Sand smooth, wipe away dust, prime the patched area, and paint to match the surrounding wall.
When to Call a Professional
A single crack that comes back repeatedly after proper taping, cracks wider than about 1/4 inch, or diagonal cracks at door/window corners across multiple rooms can indicate the house is settling or has a structural issue — worth having a contractor or structural engineer take a look rather than just re-patching.