Drywall cracks are common in homes and commercial buildings. A small crack may seem like a simple cosmetic issue, but the location, size, and pattern of the crack can sometimes point to a larger problem.
Some drywall cracks develop because a building naturally settles. Others can result from changes in temperature and humidity, poor installation, moisture, movement in the structure, or damage to the drywall. Knowing what caused the crack is important because simply filling it with joint compound may only provide a temporary fix.
In this guide, HighStyle Painting explains the most common causes of drywall cracks, how to identify different types of cracks, how they can be repaired, and when it is better to have the wall professionally inspected.
Why Does Drywall Crack?
Drywall is a rigid material, while the structure around it can move slightly over time. Changes in the framing, temperature, humidity, moisture levels, or foundation can place stress on drywall and its joints.
Common causes include:
- Normal building settlement
- Temperature and humidity changes
- Poor drywall installation
- Joint compound or tape problems
- Structural movement
- Moisture or water damage
- Impact or physical damage
- Improperly supported drywall
- Movement around doors and windows
- Seasonal changes in the building
The appearance of the crack can provide useful clues about the underlying cause.
1. Normal House Settlement
One of the most common reasons for drywall cracks is natural settling.
New construction materials can shift slightly as a building settles into its foundation. Even older homes can experience minor movement over time. This movement can create small cracks around drywall seams, corners, doors, windows, and ceilings.
Small, narrow cracks that remain stable are often less concerning than cracks that continue to grow or appear alongside other signs of structural movement.
What Do Settlement Cracks Look Like?
Settlement-related drywall cracks may be:
- Thin and narrow
- Located near drywall joints
- Found around doors or windows
- Visible near ceiling and wall intersections
- Relatively short
- Stable over time
If a crack continues getting wider or longer, it is worth having the area inspected rather than repeatedly covering it with paint.
2. Temperature and Humidity Changes
Drywall and the materials supporting it can respond to changes in temperature and humidity.
During seasonal changes, wood framing can expand and contract. Drywall joints may also experience stress as indoor conditions change.
This can lead to small cracks, especially around seams and corners.
Maintaining relatively consistent indoor humidity and temperature can help reduce excessive movement, although some seasonal movement is normal.
3. Poor Drywall Installation
Installation problems can also contribute to cracking.
For example, drywall may crack when:
- Panels are not properly secured
- Fasteners are spaced incorrectly
- Joints are poorly finished
- Too little joint compound is used
- Drywall tape is installed incorrectly
- Panels are improperly fitted
- Seams are placed in areas prone to movement
If the underlying installation problem is not corrected, repairing the visible crack may not provide a lasting result.
4. Problems With Drywall Tape or Joint Compound
Many cracks occur directly over drywall seams.
Drywall panels are joined together using joint tape and joint compound. If the tape is loose, improperly installed, or damaged, cracks can develop along the seam.
Joint compound can also crack if it is applied too thickly, dries too quickly, or is subjected to movement before it has properly bonded.
In these cases, simply applying another layer of compound over the existing crack may not be enough. The damaged area may need to be opened, retaped, and refinished.
5. Structural Movement
Not every drywall crack is simply a cosmetic problem.
Movement within the building can place stress on walls and ceilings. Cracks associated with structural movement may become larger over time or appear in several areas.
Pay closer attention to cracks that are:
- Wide or rapidly growing
- Diagonal and extending from corners
- Appearing across multiple walls
- Accompanied by doors or windows that suddenly stick
- Associated with uneven floors or ceilings
- Appearing along with other visible signs of movement
A painting contractor can repair the drywall finish, but suspected structural issues should be evaluated by an appropriately qualified professional before cosmetic repairs are completed.
6. Moisture and Water Damage
Water is another important cause of drywall problems.
A leaking roof, plumbing problem, overflowing fixture, condensation, or other source of moisture can weaken drywall. As the material becomes wet and then dries, it can swell, shrink, soften, stain, or deteriorate.
Water-damaged drywall may show:
- Cracking
- Bubbling paint
- Brown or yellow stains
- Soft spots
- Swollen areas
- Peeling paint
- Sagging
If moisture is the cause, repairing the crack alone will not solve the problem. The source of the water should be identified and corrected first.
Damaged drywall may then need to be removed and replaced before the surface is primed and painted.
7. Impact or Physical Damage
Drywall can crack when it is hit or subjected to pressure.
Common examples include:
- Furniture hitting a wall
- Moving large objects
- Door handles striking walls
- Children or pets causing accidental damage
- Installing or removing fixtures
- Moving electrical or plumbing components
These cracks are usually easier to identify because there may be a visible dent, hole, or impact mark around the damaged area.
8. Cracks Around Doors and Windows
Cracks around doors and windows deserve attention because these areas experience movement from both the building and the openings themselves.
A small crack at the corner of a door or window can sometimes result from normal movement or drywall joint stress.
However, large, diagonal, or repeatedly returning cracks should be investigated to determine whether movement is occurring behind the drywall.
Different Types of Drywall Cracks
The pattern of a drywall crack can provide clues about what may be happening.
Hairline Cracks
Hairline cracks are very thin and are often caused by minor movement, drying, settling, or changes in temperature and humidity.
Small stable cracks may be repaired with suitable joint compound and refinished.
Vertical Cracks
Vertical cracks can occur along drywall seams or because of movement in the wall.
Their significance depends on their size, location, and whether they are changing over time.
Horizontal Cracks
Horizontal cracks can result from drywall joint problems, movement, moisture, or other issues.
A long horizontal crack should be evaluated rather than automatically treated as a simple cosmetic defect.
Diagonal Cracks
Diagonal cracks, especially those extending from the corners of doors and windows, may be associated with movement.
They do not automatically indicate a serious structural problem, but larger or worsening diagonal cracks deserve closer attention.
Ceiling Cracks
Ceiling cracks can develop because of drywall joint movement, building settlement, moisture, or other causes.
Cracks accompanied by sagging, staining, or soft drywall should receive prompt attention because moisture or another underlying issue may be involved.
How to Repair a Small Drywall Crack
A small, stable drywall crack can often be repaired as part of normal wall maintenance.
Step 1: Inspect the Crack
Start by examining the crack.
Check its:
- Width
- Length
- Location
- Direction
- Surrounding paint
- Nearby drywall condition
Also check whether the crack appears to be getting larger.
Step 2: Remove Loose Material
Loose paint, drywall compound, or damaged material should be removed carefully.
The surface needs to be stable before applying new repair material.
Step 3: Prepare the Surface
The damaged area should be cleaned and prepared so the repair material can properly adhere.
For a simple hairline crack, preparation may be minimal. Larger cracks may require opening the crack slightly and addressing the drywall joint or tape underneath.
Step 4: Apply Joint Compound
Apply an appropriate drywall joint compound over the prepared area.
For larger repairs, drywall tape may be necessary to reinforce the joint and reduce the chance of the crack returning.
Step 5: Let It Dry
Allow the compound to dry according to the product instructions.
Trying to sand or repaint the repair too soon can affect the finish.
Step 6: Sand the Repair
Once dry, lightly sand the repaired area until the surface is smooth and blends with the surrounding wall.
Avoid excessive sanding because it can damage the drywall surface.
Step 7: Prime the Repaired Area
A primer helps seal the repaired surface and provides a more consistent base for paint.
Skipping primer can sometimes cause the repaired section to absorb paint differently from the surrounding wall.
Step 8: Repaint the Wall
After the repair and primer are fully dry, repaint the area.
For the best appearance, painting the entire wall may provide a more uniform finish, especially if the existing paint has aged or faded.
How Do You Repair a Large or Repeatedly Cracking Area?
Larger cracks often require more than surface filling.
Depending on the cause, the repair may involve:
- Removing damaged material
- Checking the drywall underneath
- Replacing damaged drywall if necessary
- Securing loose drywall
- Replacing damaged or loose tape
- Applying joint compound
- Sanding and smoothing the surface
- Priming the repaired area
- Repainting the wall or ceiling
The correct repair method depends on why the crack developed in the first place.
If the underlying movement continues, even a properly finished repair may eventually crack again.
When Should You Call a Professional?
Not every drywall crack requires professional service. Small cosmetic cracks can sometimes be handled as a DIY project.
Professional help becomes more useful when:
- The crack keeps coming back
- The crack is getting wider
- Several cracks are appearing
- The drywall is soft or damaged by water
- The crack is large or difficult to repair
- Drywall tape is separating
- The wall has significant dents or holes
- The repair needs to blend with a large painted surface
- You are unsure what caused the crack
If there are signs of possible structural movement, the underlying structural concern should be evaluated by an appropriately qualified professional before cosmetic drywall repairs are completed.
Can You Just Paint Over a Drywall Crack?
Painting directly over a crack usually does not solve the problem.
Paint may temporarily hide a very small hairline crack, but the crack can remain visible or reopen as the wall moves.
For a proper repair, the damaged area should generally be prepared, repaired, smoothed, primed, and then painted.
This approach creates a cleaner finish and addresses the visible damage instead of simply covering it.
How Can You Prevent Drywall Cracks?
Some drywall cracking is difficult to prevent completely because buildings naturally move.
However, homeowners can reduce avoidable problems by:
- Keeping indoor humidity reasonably consistent
- Addressing plumbing leaks quickly
- Fixing roof or exterior water intrusion
- Maintaining proper ventilation
- Avoiding unnecessary impact to walls
- Having drywall installed correctly
- Using proper materials for drywall joints
- Monitoring cracks that repeatedly return
- Repairing damaged areas before they become larger
Regularly checking walls and ceilings can also help you identify moisture or movement problems early.
Should You Repair Drywall Before Painting?
Yes, drywall should generally be repaired before painting.
Painting over damaged drywall can make imperfections more noticeable rather than hiding them. Cracks, dents, holes, uneven patches, and damaged seams can all affect the final appearance of a painted surface.
Proper preparation may include:
- Crack repair
- Hole repair
- Joint repair
- Sanding
- Surface cleaning
- Priming
- Caulking where appropriate
Once the surface is smooth and properly prepared, paint can provide a much more consistent finish.
Drywall Repair and Painting Should Work Together
A successful wall repair is about more than filling a crack.
The repaired area needs to blend with the surrounding surface. Differences in texture, sanding, primer, or paint can make a repaired section stand out even after the crack itself has disappeared.
That is why drywall preparation and painting are closely connected. A properly prepared surface gives the paint a smoother and more consistent base.
HighStyle Painting can help homeowners address wall preparation and painting needs when drywall repairs are part of a larger painting project.
Frequently Asked Questions
Are drywall cracks normal?
Small drywall cracks can occur because of normal building movement, settling, temperature changes, humidity, or joint movement. However, cracks that are large, worsening, recurring, or accompanied by other building problems should be evaluated.
How do I know if a drywall crack is serious?
The size, location, pattern, and progression of the crack all matter. A crack that continues to grow, appears in multiple areas, or is accompanied by sticking doors, uneven surfaces, water damage, or other changes deserves closer inspection.
Can I repair drywall cracks myself?
Small cosmetic cracks can often be repaired with basic drywall repair materials and careful preparation. Larger, recurring, or water-damaged cracks may require professional repair or evaluation.
Why does my drywall crack after I repair it?
The original cause may still be present. Building movement, seasonal changes, loose drywall, damaged tape, moisture, or an underlying structural issue can cause a repaired crack to return.
Do I need to replace drywall because of a crack?
Not always. Small cracks can often be repaired. Replacement may be necessary when drywall is extensively damaged, softened by moisture, broken, or unable to provide a stable surface for repair.
Should I repair cracks before painting?
Yes. Repairing cracks and other surface imperfections before painting helps create a smoother and more uniform finished surface.
Can humidity cause drywall cracks?
Changes in humidity can contribute to movement in drywall and the materials supporting it. Repeated expansion and contraction can place stress on joints and finishes.
Why are cracks appearing around my windows?
Cracks around windows can result from normal movement, drywall joint stress, settlement, or other forms of building movement. The size, direction, and progression of the crack help determine whether further evaluation is appropriate.
Can water damage cause drywall to crack?
Yes. Water can weaken drywall and cause swelling, shrinking, softening, staining, peeling paint, and cracking. The source of moisture should be corrected before damaged drywall is repaired.
Final Thoughts
Drywall cracks can have many causes, from normal settling and seasonal movement to installation problems, moisture, impact, and structural movement. The most important step is to identify the likely cause before deciding how to repair the visible damage.
Small, stable cracks may only require basic preparation and drywall compound. Larger, recurring, or moisture-related cracks may require more extensive repair and investigation.
If your walls need drywall repair, surface preparation, or a fresh coat of paint, HighStyle Painting can help prepare the surface for a clean, finished result. Proper preparation is an important part of any successful painting project, and repairing wall imperfections before painting can make a noticeable difference in the final appearance.