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Concrete Slab Foundation Repair
A concrete slab foundation is a single, thick layer of concrete poured directly onto the ground, serving as the base of a home or building. While this type of foundation is durable and cost-effective, it can develop issues over time due to soil movement, moisture changes, and structural stress. When problems arise, foundation repair is necessary to restore stability and prevent further damage.
Common Signs of Foundation Issues
Recognising early warning signs of foundation problems can help prevent costly repairs. Here are some common indicators that your concrete slab foundation may need attention:
Cracks in the Slab or Walls
- Small hairline cracks are common, but large or widening cracks could indicate foundation movement.
- Cracks accompanied by moisture leaks or uneven surfaces suggest more severe structural problems.
Uneven or Sunken Slab
- Portions of the slab may sink or become unlevel due to soil erosion, poor compaction, or water damage.
- This can lead to trip hazards, structural instability, and difficulty installing flooring.
Foundation Uplift or Heaving
- The slab may rise due to excess moisture, expansive clay soils, or frost heave.
- This often leads to bulging floors, cracked walls, and doors/windows that won’t close properly.
Gaps Between Walls, Floors, and Ceilings
- Noticeable separation of walls from floors or ceilings could indicate foundation shifting.
- In severe cases, wall cracks or drywall separation may develop.
Sticking or Misaligned Doors and Windows
- As the foundation moves, door and window frames can become distorted, making them difficult to open or close.
- This is a strong sign of foundation instability.
Plumbing Issues or Water Intrusion
- Slab foundations often have plumbing pipes embedded within them. When the foundation shifts, it can cause pipe leaks, water damage, and increased utility bills.
- Water pooling near the foundation can also weaken the structure over time.
Concrete Slab Foundation Repair Methods
Slab Jacking
- This method is used for lifting and leveling sunken slabs.
- It involves injecting a cement slurry or expanding polyurethane foam beneath the foundation to fill voids and restore elevation.
- Best for: Minor settling, uneven slabs, and voids under the foundation.
- Pros: Cost-effective, quick repair time, and minimally invasive.
- Cons: May not be a permanent fix for ongoing soil movement.
Piering or Underpinning
- This technique stabilizes foundations by driving steel or concrete piers deep into the soil until they reach stable ground.
- Types of piers used:
- Push Piers – Driven into the soil using hydraulic force.
- Helical Piers – Screwed into the ground like large screws.
- Drilled Concrete Piers – Require drilling and pouring concrete deep below the foundation.
- Best for: Severe settling, unstable soil, and structural reinforcement.
- Pros: Provides long-term stability, supports heavy structures.
- Cons: More expensive and requires professional installation.
Crack Injection
Used to seal foundation cracks and prevent water infiltration.
Epoxy is a strong adhesive that binds cracks, while polyurethane foam expands to fill voids.
- Best for: Minor to moderate cracks that are not due to serious structural failure.
- Pros: Prevents moisture damage, strengthens the foundation.
- Cons: Not suitable for major structural shifts.
Soil Stabilisation and Drainage Correction
- Many foundation issues arise from expansive clay soils, poor drainage, or soil erosion.
- Solutions include:
- Installing proper drainage systems (French drains, gutters, grading).
- Adding soil stabilizers (lime or chemical injections).
- Using moisture barriers to prevent soil expansion.
- Best for: Preventing future foundation movement.
- Pros: Cost-effective and prevents recurring damage.
- Cons: May not fix existing foundation damage.
Preventing Foundation Problems
Taking preventive measures can help protect your foundation and extend its lifespan.
Maintain Proper Drainage – Ensure that gutters, downspouts, and grading direct water away from the foundation.Standing water can cause soil expansion and foundation movement.
Control Soil Moisture Levels – Avoid extreme drying or excessive water saturation around your foundation.Consider using soaker hoses during dry seasons to maintain soil consistency.
Fix Plumbing Leaks Promptly – Slab leaks can erode soil and weaken the foundation. Monitor your water bill for unexpected spikes.
Limit Tree and Shrub Growth Near the Foundation – Large tree roots can absorb moisture and cause soil shrinkage, leading to foundation settling.
Schedule Regular Inspections – A professional foundation inspection every few years can catch minor issues before they become costly repairs.
Concrete slab foundation repair is essential to maintaining the stability and safety of your home or building. Whether you’re dealing with cracks, sinking, or severe shifting, early detection and professional repair can save you money and prevent further damage.
Get a FREE quote
Arrange a site assessment in 3 simple steps:
Step 1
Submit your enquiry using our online form. Include a brief message about the type of foundation issues you are experiencing.
Step 2
Our friendly customer service team will be in touch to schedule a site assessment that suits you.
Step 3
One of the Mainmark experts will visit your home or property, assess the damage, and ascertain the likely cause. They will establish the approach needed, creating a plan specific to the needs of your building and provide you with a detailed quote.
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Mainmark Ground Engineering Pty Ltd
ABN: 51 606 182 503
