Cracks in plaster walls are a common issue for homeowners in both new and older homes. Whether these cracks are the result of natural settling, temperature fluctuations, or other causes, understanding when to address them yourself and when to seek professional help can save you time and money in the long run.
This guide provides a comprehensive look at plaster wall cracks, including common causes, types of cracks, and when it’s time to call in an expert.
Let’s get straight to the point
Plaster cracks can be caused by settling, temperature changes, vibrations, or structural issues.
Minor cracks are usually DIY repairs, but larger or widening cracks, especially near doors/windows or with moisture, need professional attention. Look for crack patterns (vertical, horizontal, stair-step) to assess severity.
Professionals ensure proper diagnosis, quality repairs, and long-term solutions. If in doubt, hire a pro to prevent future damage.
What Causes Plaster Cracks?
Plaster cracks can appear in any home, but they are more noticeable in older houses with traditional plaster finishes. There are several reasons why cracks form in plaster walls. Some of the most common causes include:
1. House Settling
Over time, all houses settle into their foundations. This natural settling process can cause minor cracks in plaster walls, especially in older homes. These cracks are often harmless and can be repaired easily.
2. Temperature Changes
Temperature fluctuations, such as the heat from a wood-burning stove or the cold air from an open window, cause plaster to expand and contract. Over time, this movement can lead to cracks, particularly in homes that experience extreme weather conditions.
3. External Vibrations
Vibrations from nearby traffic, trains, or construction work can cause cracks in plaster walls. Homes located in busy urban areas are more likely to experience this issue, particularly if the plaster is already weakened.
4. Structural Shifts
If a building’s foundation is compromised, the entire structure may shift, putting additional stress on the plaster. These shifts can cause significant cracks, often leading to structural issues in the long term.
Types of Plaster Cracks
Understanding the type and severity of plaster cracks is crucial when determining whether you need professional assistance. Cracks vary in size, shape, and cause. Here are the most common types of plaster cracks and their potential implications:
1. Hairline Cracks
Hairline cracks are typically very thin (less than 1/4 inch wide) and are often a result of normal settling or minor temperature changes. These cracks are generally not a cause for concern and can be easily fixed using a patching compound.
2. Moderate Cracks
Cracks between 1/4 and 1/2 inch wide are more noticeable and may require a bit more attention. While these cracks could still be due to normal settling, it’s a good idea to consult a professional to determine if a simple patch will suffice or if further repairs are necessary.
3. Large Cracks
Any crack wider than 1/2 inch may indicate significant structural problems. Large cracks are often associated with foundation issues or shifting walls, which need to be assessed by a structural engineer or professional plasterer.
Identifying Serious Cracks: When to Seek Help
Certain cracks in plaster are more than just cosmetic issues. If left untreated, these cracks can lead to further damage and potentially jeopardise the structural integrity of your home. Below are warning signs that may indicate it’s time to call in a professional:
1. Crack Movement
If a crack continues to widen over time, this is a clear sign of ongoing structural issues. Cracks that change or grow in size should be addressed promptly.
2. Misaligned Doors or Windows
Cracks that cause doors or windows to become misaligned or stick are often a sign that the walls or foundation are shifting. These cracks may indicate significant movement, and professional intervention is required to assess the problem.
3. Moisture Around Cracks
Water seeping through cracks can worsen damage and lead to mould growth. If you notice moisture around a crack, it’s critical to call a professional immediately to prevent further damage and health issues related to mould.
4. Cracks Larger Than 5mm
Cracks larger than 5mm should always be inspected by a professional. Large cracks may indicate issues with the foundation, framing, or other structural elements that require expert evaluation and repair.
5. Diagonal Cracks
Diagonal cracks often suggest foundation movement or severe structural shifts. These types of cracks are more serious and should not be ignored.
Common Crack Patterns and What They Mean
The pattern of a plaster crack can also help determine the severity of the issue. By understanding different crack patterns, you can better assess the potential causes and decide whether to call a professional.
1. Vertical Cracks
Vertical cracks are common and are often a result of the house settling. These cracks are generally not serious but should be monitored over time. If they begin to widen or change shape, it may be time to consult a professional.
2. Horizontal Cracks
Horizontal cracks are more concerning and can indicate structural issues, such as foundation problems. A professional should inspect these types of cracks as soon as possible to determine their cause and fix the issue before it worsens.
3. Stair-Step Cracks
Stair-step cracks appear along the edges of walls and often indicate serious structural movement, such as foundation shifting. These cracks require immediate professional attention.
4. Multiple Cracks in One Area
If several cracks appear in the same area, it could indicate widespread stress on the wall or foundation. Multiple cracks often signal a more significant issue, and a professional should assess the situation to prevent further damage.
How to Repair Minor Cracks in Plaster
While professional help is often required for large cracks, minor cracks in plaster can often be repaired by homeowners themselves. Here are some tips for repairing smaller cracks:
1. Clean the Crack
Before beginning any repair work, ensure the crack is clean and free of dust or debris. Use a brush or vacuum cleaner to remove any dirt or loose plaster from the crack.
2. Apply Plaster Patch
For small cracks, you can use a plaster patching compound. Apply a thin layer over the crack, using a putty knife to smooth it out. Allow it to dry completely before sanding it smooth.
3. Repaint the Wall
Once the plaster repair is complete, you may need to repaint the wall to match the surrounding area. Choose a paint that is appropriate for plaster walls and ensure the surface is smooth before applying the new coat.
Why Hire a Professional for Plaster Crack Repairs?
While DIY repairs may be sufficient for minor cracks, larger or more complicated issues require professional attention. Here’s why hiring a professional plasterer is beneficial:
1. Expert Diagnosis
A professional can accurately diagnose the cause of the crack, whether it’s due to settling, temperature changes, or a more serious structural issue. This ensures the problem is addressed correctly and not just patched over.
2. Quality Repairs
Professionals use high-quality materials designed for durability and flexibility. These materials are often more robust than what you can buy at the hardware store, ensuring the repair lasts longer.
3. Seamless Finish
A skilled plasterer will ensure that the repair blends seamlessly with the existing wall, leaving no visible signs of damage. This ensures that your home remains aesthetically pleasing and maintains its value.
4. Peace of Mind
Hiring a professional ensures that the repair is done according to industry standards, with proper techniques and materials. Most professionals offer warranties on their work, giving you peace of mind that the issue won’t reoccur.
How to Choose a Professional Plasterer
Finding the right plasterer to repair your cracks is crucial. Here are some tips to help you make the right choice:
1. Get Recommendations
Ask family, friends, or neighbours if they have any recommendations for a reputable plasterer. Word-of-mouth referrals are often the best way to find someone trustworthy.
2. Check Online Reviews
Online reviews can provide insights into a plasterer’s quality of work. Look for consistently positive feedback to help you narrow down your options.
3. Request Multiple Quotes
It’s always a good idea to get quotes from several professionals before making a decision. Comparing pricing and services can help you find the best deal.
4. Verify Credentials
Ensure the plasterer is licensed and insured. This protects you in case of any accidents or issues that may arise during the repair process.
Preventing Future Plaster Cracks
Although you can’t completely prevent plaster cracks, there are steps you can take to minimise the chances of them occurring:
1. Maintain Consistent Humidity
Plaster can expand and contract with changes in humidity. Keep humidity levels consistent in your home by using a humidifier or dehumidifier as necessary.
2. Fix Foundation Issues Early
If you notice signs of foundation problems, such as uneven floors or doors that stick, address them immediately. Early intervention can prevent plaster cracks from recurring.
3. Regular Inspections
Check for any new cracks or changes in existing cracks periodically. Monitoring these issues can help you catch problems early before they become major.
Conclusion
Plaster cracks are a common concern for homeowners, but most are harmless and can be repaired with simple DIY methods. However, larger cracks or cracks that show signs of movement or moisture should be addressed by a professional. By recognising the signs of serious damage early, you can prevent further issues and keep your home in top condition.
If you’re ever unsure about the severity of a plaster crack, don’t hesitate to consult a professional plasterer. Their expertise can save you time, money, and stress in the long run.
Frequently Asked Questions
Are All Cracks In My Plaster Walls A Cause For Concern?
No, not all cracks are a cause for concern. Hairline cracks (less than ¼ inch) are quite common and often result from natural settling or minor temperature fluctuations. However, larger cracks, cracks with specific patterns (diagonal, stair-step), or cracks that show signs of movement require professional evaluation.
Can I Fix Plaster Wall Cracks Myself?
For small hairline cracks, a DIY approach might be possible using a patching compound specifically designed for plaster. However, for larger cracks, cracks with unusual patterns, or if you’re uncomfortable with DIY repairs, it’s always best to consult a professional for a proper assessment and lasting repair solution.
What Are The Benefits Of Hiring A Professional To Repair Cracks?
Hiring a professional plasterer offers several advantages. They can diagnose the root cause of the crack to prevent future occurrences. They use proper techniques and high-quality materials for long-lasting and virtually invisible repair. Additionally, professionals provide peace of mind, knowing your home’s structural integrity is secure.
How Can I Find A Qualified Professional To Repair My Plaster Wall Cracks?
Seek recommendations from friends, family, or neighbours who have recently had similar repairs done. Online review platforms can also be helpful in researching local plasterers and structural engineers, allowing you to compare their experience, professionalism, and customer reviews. Always get quotes from multiple qualified professionals and verify their licensing and insurance before signing any contracts.
What Other Factors Can Cause Cracks In My Plaster Walls Besides Settling?
Traffic vibrations from busy roads or replacing old windows without proper support (lintels) can also contribute to plaster wall cracks. Additionally, moisture damage around cracks can exacerbate them and lead to mould growth. If you notice moisture around a crack, don’t attempt a DIY repair – call a professional to address both the crack and the moisture source.
