Why Door Frames Crack
Doors and windows are holes in your walls. That's structurally significant. The framing around those openings carries load differently than a solid wall section, and stress concentrates at the corners.
When a house settles, and they all do, that stress shows up as cracks radiating from door frame corners. Usually diagonal, running at roughly 45 degrees from the upper corners toward the ceiling. Sometimes you'll see them at the lower corners too, heading toward the floor.
According to the International Association of Certified Home Inspectors, minor settling cracks around doors and windows are among the most common drywall issues in homes over 5 years old. They rank them as cosmetic in the vast majority of cases.
Settling vs Seasonal Movement
Settling is the house slowly compressing into the soil over years. It mostly stops after 5 to 10 years, though it never fully ends. Seasonal movement is the house expanding and contracting with temperature and humidity shifts. That one never stops.
Both cause door frame cracks. Settling creates cracks that appear and stabilize. Seasonal movement creates cracks that open in winter and close in summer, or vice versa. My hallway door frame crack gets wider every January and nearly disappears by July. I've measured it. About 1/16 inch difference between seasons.
When It Might Be Something More
A crack at a door corner isn't automatically harmless. Watch for these signs: the crack is wider than 1/4 inch, one side is higher than the other (displacement), the door no longer closes properly, or the crack appeared suddenly after being stable for years.
My neighbor Linda noticed her front door started sticking right around the time diagonal cracks appeared above both corners. Turned out her foundation had shifted on one side. The door frame wasn't square anymore. That repair cost her around $6,200 for foundation piers. The drywall cracks were symptoms, not the problem.
What You'll Need
Gather everything before you start. You won't need much.
- Utility knife
- 6-inch drywall knife
- 10 or 12-inch drywall knife
- Setting compound (45-minute or 90-minute)
- Pre-mixed all-purpose joint compound
- Paper drywall tape
- 120-grit and 220-grit sandpaper or sanding sponge
- Dust mask and safety glasses
- Drop cloth
- Primer and paint for touch-up
Total cost if you're starting from scratch: about $30 to $45. If you already have knives and compound from previous projects, the tape and sandpaper are maybe $8.
Step 1: Prep the Crack
This is where my first attempt went wrong. I just smeared spackle into the crack and painted over it. Looked great for about six weeks. Then the crack came right back, now with a visible bump of old spackle next to it.
You need to remove the damaged material first. Score along both sides of the crack with your utility knife, about an inch and a half out from the crack on each side. You're cutting through the existing paint and compound down to the tape layer, or to bare drywall if there's no tape.
Peel away any loose or cracked compound. If there's tape underneath and it's lifting or bubbling, pull it off too. Get back to solid, well-bonded material on both sides. The crack area should be slightly recessed compared to the surrounding wall when you're done prepping.
Widening Narrow Cracks
For hairline cracks, use the corner of your knife to open the crack slightly. A V-shaped groove gives the compound something to grab. A hairline crack filled with compound is just compound sitting on top of the crack. It'll fail. A small groove fills with compound that keys into both sides.
Step 2: First Coat with Setting Compound
Mix your setting compound to a peanut butter consistency. Not runny. You want it to stay where you put it without sagging, especially above a door frame where gravity is working against you.
Apply a thin bed coat into and over the crack with your 6-inch knife. Press firmly to work the compound into the groove. Then lay a strip of paper tape over the wet compound, centered on the crack. Press the tape in with your knife, squeezing out excess compound from underneath but leaving enough for a solid bond.
The tape should be fully saturated with compound underneath. Dry spots will bubble later. I learned this the annoying way on my bathroom door frame. Bubbled tape means doing the whole repair over again.
Skim a thin coat of compound over the tape to cover it. Don't build it up thick. This is just the first coat. Let it set fully according to the product timing.
Why Setting Compound for the First Coat
Setting compound (hot mud) cures by chemical reaction and bonds harder than pre-mixed joint compound. It won't shrink as much and it holds up better over stress points like door frames. The USG application guide recommends setting-type compounds for repair work at stress points for exactly this reason.
Pre-mixed is fine for the second and third coats where you need sandability more than strength. But the first coat against the tape should be the strong stuff.
Step 3: Second Coat
Wait for the first coat to fully cure. With 45-minute compound, give it at least an hour to be safe. The surface should feel hard and dry, not cool or damp.
Lightly knock down any ridges or bumps from the first coat with your knife or a quick pass of 120-grit sandpaper. You're not sanding smooth, just removing high spots.
Apply pre-mixed all-purpose compound over the first coat, feathering the edges out 4 to 6 inches beyond the first coat on each side. Use your 10-inch knife for this. Smooth, even strokes. You're building out a gradual transition from the repair area to the surrounding wall.
Let dry 24 hours. Pre-mixed compound dries by evaporation, not chemical reaction, so it needs more time.
Step 4: Third Coat and Feathering
Same process. Sand lightly to remove ridges. Apply another coat of pre-mixed compound, feathering even wider this time. You want the transition from repaired area to original wall to be so gradual that you can't feel it with your hand.
Steve told me that the difference between a visible repair and an invisible one is all in the feathering. "Nobody screws up the crack fill," he said. "They screw up the edges." He's right. A repair that's perfectly smooth in the middle but has hard edges where the compound meets the original wall will show through paint like a speed bump.
On most door frame cracks, two coats beyond the tape is enough. If you can still see or feel the transition, do a fourth skim coat feathered even wider. Better to spend 15 minutes on another thin coat than to live with a visible patch.
Step 5: Sand and Prime
Once fully dry, sand with 120-grit to smooth the surface, then finish with 220-grit. Use a sanding sponge for better control around the door frame edges. Sand less than you think you need to. Over-sanding exposes the tape and means recoating.
Wipe down with a damp cloth to remove dust. Let it dry.
Prime the entire repaired area with a PVA drywall primer or a quality primer-sealer. The compound absorbs paint differently than the surrounding painted wall. Without primer, the repaired area will flash, meaning it'll look different even with the same paint color.
After primer dries, paint the wall. For the best blend, paint the whole wall section from corner to corner rather than just spot-painting the repair area.
What I'd Do Differently Now
My first door frame crack repair used lightweight spackle and no tape. Failed in six weeks. Second attempt used pre-mixed compound and mesh tape. Better, but the crack reappeared after about eight months. Third attempt used setting compound, paper tape, and proper feathering. That was three years ago. Still holding.
The lesson is that door frames move. The repair has to be strong enough to handle some movement without cracking again. Spackle can't do that. Mesh tape can't do that. Setting compound with paper tape can.
The other thing I'd change is my timeline expectations. I wanted to fix and paint in one day. That leads to coating over compound that isn't fully dry, which leads to shrinkage and cracking. Three days is realistic. Apply tape coat one evening, second coat the next evening, third coat and sand the third day. Paint whenever it's dry. Short sessions. No rushing.
Preventing Future Cracks
You can't fully prevent door frame cracks in a house that moves. But you can slow them down.
Keep indoor humidity between 30% and 50% year-round. Wild swings in humidity cause more wood expansion and contraction, which means more stress at door frames. I added a whole-house humidifier to our furnace and the winter cracking slowed noticeably.
If you're doing a renovation and have the walls open, install corner bead around door frames instead of relying on tape alone. Metal or vinyl corner bead handles movement better than paper tape at these stress points.
Accept that some cracks are recurring. My hallway door will probably crack again in a few years. That's fine. A touch-up repair takes 30 minutes of actual work once you know what you're doing. Some things you maintain rather than permanently fix.