Why the Crack Keeps Coming Back
Most interior corner cracks, the ones between a wall and a ceiling or between two interior walls, aren't structural issues. They're movement cracks. The wood framing behind your drywall responds to seasonal humidity changes by shrinking and swelling. According to the American Wood Council, dimensional lumber changes moisture content measurably across seasons, which translates to real movement across a framed wall assembly.
The wall and ceiling drywall panels are attached to separate framing members. When those members move at slightly different rates, the joint between them gets pulled apart. A thin layer of compound can't stretch. It cracks instead.
This is why patching a movement crack with more compound is temporary at best. You're putting a rigid material across a joint that moves. You already know how that ends.
Identifying Your Type of Corner Crack
Before picking a repair approach, figure out what kind of crack you have. The treatment is different depending on the cause.
Wall-to-Ceiling Joint Cracks
These run horizontally where the wall meets the ceiling. They open and close seasonally. If you look closely, you may notice the crack is slightly wider in winter than summer. These are almost always movement cracks and should be fixed with paintable latex caulk, not compound.
Corner Bead Cracks
These run vertically or diagonally along outside corners, often starting at a point and spreading outward. They're usually caused by damaged or improperly installed corner bead, or by compound applied too thickly over the bead. These require compound and proper feathering, not caulk.
Stress Cracks
Diagonal cracks that radiate from corners of door and window frames are stress cracks from structural loading or settling. Fixing these correctly often requires addressing the underlying framing issue. If a stress crack is getting longer or wider over time, get a structural inspection before trying to patch it again.
Fixing Wall-to-Ceiling Cracks with Caulk
This is the fix that actually works for seasonal movement cracks. You're replacing rigid compound with a flexible material that can move without cracking.
What you need: Paintable latex caulk (not silicone, which won't accept paint), a caulk gun, a putty knife, and damp rags.
Step 1: Remove all the old compound from the crack. Use a putty knife to scrape out any loose material from the joint. Putting caulk over old compound won't stick properly.
Step 2: Prime the area if it's bare drywall. Caulk adheres much better to primed or painted surfaces than to raw compound or paper. This is the step most people skip, and it's why their caulk pulls away from the wall within a year.
Step 3: Apply a thin bead of paintable latex caulk along the joint. Tool it smooth with a wet finger in one continuous motion, keeping a damp rag handy to clean up as you go.
Step 4: Let the caulk cure for the manufacturer's recommended time before painting. Most paintable caulks need 24 to 48 hours. Painting too early causes wrinkling.
Step 5: Paint normally. Paintable latex caulk accepts paint without issues once cured.
The result is a joint that flexes slightly as the seasons change without cracking. I've had caulk repairs hold for four-plus years in my house on the same joint I patched three times with compound.
Fixing Corner Bead Cracks
If the crack is along an outside corner and involves the corner bead, caulk isn't the answer. These need compound.
First check whether the corner bead itself is loose. Push on it near the crack. If it flexes, resecure it before patching. Drive drywall screws every 8 inches along both sides of the bead to pull it tight against the corner, then patch.
For the patch: apply setting-type compound in a thin first coat, feathering it out 4 to 5 inches from the corner on both sides. Let it set fully. Sand lightly. Apply a second coat of all-purpose compound with a wider knife, feathering even further out. Sand again.
The Association of the Wall and Ceiling Industry recommends feathering corner repairs out a minimum of 6 inches from the bead for a quality Level 4 finish. Most DIY repairs I've seen are feathered maybe 2 or 3 inches, which is why you can see them from across the room.
When the Crack Is in the Middle of a Wall
Cracks that appear in the middle of a wall, not at corners, are usually at seams between drywall panels. These require digging out any loose compound, applying tape if the original tape has failed, and re-coating with compound properly feathered. If the tape is bubbling or pulling away, remove it and apply new tape before patching. Patching over failed tape delays the same crack by a season or two, nothing more.
Seam cracks that keep returning may indicate the panels weren't properly supported during installation or that the framing has significant movement. For repeated seam failures, use paper tape embedded in compound rather than mesh tape. USG's Gypsum Construction Handbook recommends paper tape for areas prone to cracking because of its superior tensile strength compared to mesh.