One of the most common causes of interior doors not being straight is uneven hinges. Over time, hinges can become loose or worn, causing the door to sag and not sit properly in its frame. This can also happen if the door was not installed correctly in the first place.1. Uneven Hinges
Another reason for interior doors not being straight is warping. This occurs when the door is exposed to moisture or extreme temperature changes, causing the wood to expand or contract unevenly. Warping can also be a result of poor quality wood or improper storage before installation.2. Warping
If your house is settling, it can also cause interior doors to become crooked. As the foundation shifts, the door frame can become misaligned, making the door sit at an angle. This is a common issue in older homes, but it can also happen in newer houses due to soil shifting or poor construction.3. Settling of the House
In some cases, interior doors not being straight is simply due to poor installation. If the frame is not level or the door was not hung correctly, it can lead to the door sitting unevenly. It's important to hire a professional or follow proper installation instructions to ensure a straight door.4. Poor Installation
Like anything, doors can also age and wear over time. As they get older, they may start to sag or become misaligned. This is especially true for hollow core doors, which are more prone to warping and shifting. If your door is on the older side, it may be time for a replacement.5. Age of the Door
Interior doors that are constantly being opened and closed can also become crooked over time. The constant movement can cause the hinges to become loose or the door to shift in its frame. This is especially true for doors in busy areas of the house, such as the bathroom or kitchen.6. Heavy Use
If your door has been exposed to water, whether from a leak or high humidity, it can cause the wood to swell and become misshapen. This can lead to the door not sitting straight in its frame. It's important to address any water damage as soon as possible to prevent further issues.7. Water Damage
In some cases, interior doors not being straight can be a sign of larger structural issues in the house. If multiple doors are crooked or you notice cracks in the walls, it could be a sign of foundation problems. It's important to address these issues promptly to prevent further damage.8. Structural Issues
Proper maintenance is key to keeping your interior doors straight. This includes regularly tightening hinges, keeping the door clean and free of debris, and addressing any issues as soon as they arise. Neglecting maintenance can lead to bigger problems down the road.9. Improper Maintenance
Lastly, the quality of the materials used for your interior doors can also play a role in how straight they stay. Cheap or low-quality materials are more likely to warp or shift over time, while higher quality materials will last longer and maintain their shape. It's worth investing in good quality doors to avoid any future problems.10. Quality of Materials
How to Fix Interior Doors That Are Not Straight

Interior doors are not just functional elements in a house, they also play a major role in the overall design and aesthetic appeal of a home. However, one common issue that homeowners may face is having interior doors that are not straight. This can be a frustrating problem that affects the visual appeal and functionality of the doors. But don't worry, there are solutions to fix this issue and restore your doors to their proper position.
Identify the Problem

The first step in fixing a crooked interior door is to identify the root cause of the problem. It could be due to the door frame being out of alignment, loose hinges, or even warping of the door itself. By pinpointing the cause, you can determine the appropriate solution to fix the issue.
Adjust the Door Hinges

One of the main reasons for a crooked door is loose or misaligned hinges. To fix this, first, remove the door from its hinges by unscrewing the hinge pins and lifting the door off. Then, tighten the screws on the hinges or replace them if they are damaged. Next, place the door back on the hinges and test to see if it is straight. If not, you may need to add additional shims to the hinges to adjust the alignment.
Shim the Door Frame

If the door frame itself is the issue, you can use shims to adjust the alignment. Start by removing the molding around the door frame and then adding shims to the areas where the frame is not straight. Place the shims in between the frame and the wall until the frame is straight and then secure the shims in place with screws. Finally, cut off any excess shims and replace the molding.
Consider Replacing the Door

If the door is warped or damaged, it may be best to replace it with a new one. This is especially true for older doors that may have become misshapen over time. When choosing a new door, make sure to measure the opening accurately to ensure a perfect fit. You can also opt for a pre-hung door which comes with its own frame, making installation easier.
Conclusion

Having interior doors that are not straight can be a frustrating issue, but with the right approach, it can be easily fixed. By identifying the root cause and using the appropriate solutions, you can restore your doors to their proper position and enhance the overall design of your home. If the problem persists, it may be best to consult a professional for further assistance.