Cracks in walls are a common concern for homeowners and can sometimes signal underlying issues with the home’s structure. While minor cracks may be easily repaired, others could point to more significant problems. Recognising the types of cracks in plaster, plasterboard, brick, and concrete walls, and knowing how to address them, is crucial for ensuring your home remains safe and visually appealing.
Identifying Different Types of Cracks in Walls
Before diving into the solutions, it’s important to understand the different types of cracks you may encounter in your home. These include:
- Hairline Cracks
These small, thin cracks typically appear in plaster and are caused by natural settling or minor shifts in the building. Hairline cracks rarely cause significant structural issues and can usually be patched up easily. - Vertical Cracks in Walls
Vertical cracks often occur in brick or plaster walls and are typically a result of the house settling over time. They are generally not a major concern unless they widen significantly. - Horizontal Cracks in Walls
Horizontal cracks can indicate structural issues, especially if they occur in the foundation or load-bearing walls. These should be addressed promptly by a professional. - Cracks in Plaster or Plasterboard
Cracks in plaster and plasterboard walls are common in older homes. These cracks may be due to poor installation, age, or natural movement. In some cases, they may also be caused by moisture damage. - Settlement Cracks
Settlement cracks happen as the foundation of the house shifts over time. These cracks can be seen as diagonal or zig-zag patterns on brick walls, and if they grow larger, they may require professional repair.
When Should You Worry About Cracks in Walls?
Cracks in walls can be a common issue in many homes, but it’s important to know when they signal a more serious problem. Minor cracks can often be repaired with basic DIY fixes, especially if they are cosmetic, such as small plaster cracks or drywall cracks. However, larger cracks, particularly vertical cracks or horizontal cracks, may indicate structural issues that require immediate attention.
If you notice that the cracks in your walls are wide, especially if they are accompanied by sagging floors, sticking doors or windows, or visible shifting in the walls, it’s time to be concerned. These could be signs of a foundation problem. Over time, homes can settle, leading to changes in the structure that result in cracks in the plaster or drywall. When foundation settlement is significant, it can cause the stumps or supports under your home to deteriorate, leading to more severe structural issues and worsening cracks.
In cases like this, restumping (or reblocking) the house is often necessary to restore the foundation’s stability. This process involves replacing old, deteriorating stumps with concrete stumps, which can provide a more stable base and help prevent future cracks in the walls. If you’re renovating or already working on your home, this may be an ideal time to address any potential foundation problems to avoid more costly repairs later on.
How to Fix Cracks in Walls
The method for fixing cracks in walls depends on the type of crack and the material of the wall. Here’s a step-by-step guide for the most common types of wall cracks.
1. Fixing Cracks in Plaster Walls
Plaster cracks are common, especially in older homes. To fix plaster cracks:
- Clean the crack: Use a scraper to remove loose plaster and dust from the crack.
- Apply plaster filler: For smaller cracks, use a plaster repair compound. For larger cracks, you may need to apply a bonding agent first.
- Smooth the surface: Once the filler is dry, sand it down to match the surrounding wall.
- Paint over the patch: Once the crack is filled and smooth, repaint the wall to blend the repair.
2. Repairing Cracks in Plasterboard Walls
Plasterboard cracks are also common but easier to repair than plaster walls. Here’s how to fix cracks in plasterboard:
- Prepare the crack: Use a utility knife to cut along the crack to create a clean edge.
- Fill the crack: Apply a plasterboard joint compound or spackling paste into the crack.
- Smooth the compound: Use a drywall knife to smooth out the compound and ensure it is level with the rest of the wall.
- Sand and paint: After the compound dries, sand it smooth and apply touch-up paint.
3. How to Fix Cracks in Brick or Concrete Walls
Cracks in brick or concrete walls require a more involved repair process. Follow these steps for larger cracks:
- Clean the crack: Remove any dirt, debris, or loose material from the crack.
- Apply a masonry crack filler: Use a concrete crack filler or hydraulic cement to fill the crack. This will help prevent water from seeping in and causing further damage.
- Smooth the filler: Once applied, smooth out the filler to match the wall’s surface.
- Seal the crack: For added protection, apply a sealant over the repaired area to prevent future moisture damage.
4. How to Fix Structural Cracks in Walls
Structural cracks, especially those in load-bearing walls or foundations, require immediate attention. These cracks can compromise the stability of your home and should not be repaired by homeowners without professional assistance. A structural engineer will assess the damage and recommend appropriate repairs, such as:
- Reinforcing the foundation: This may involve installing piers or using underpinning techniques to stabilise the foundation. In cases of deteriorating or compromised stumps, restumping may also be necessary to replace old supports with more durable concrete stumps.
- Repairing load-bearing walls: These repairs often involve adding support beams or braces to stabilise the structure.
Addressing foundation issues at the early stages can prevent further structural damage and reduce the risk of more severe cracking or shifting in the future.
When to Call a Professional
If you notice large cracks in walls, especially structural ones affecting your home’s stability, it’s essential to call a professional. A contractor or structural engineer can assess the damage and recommend the best course of action. Restumping may be necessary if foundation issues are involved. D.J. Baker and Son specialises in restumping and foundation repairs to ensure your home remains structurally sound.
Cracks in walls are common, but addressing them early can prevent costly damage. Whether it’s minor plaster cracks or significant structural issues, seeking professional help is crucial to keeping your home safe and stable for years to come.
