Introduction: Why Paver Stability Matters
Interlocking Pavers are a popular choice for driveways, patios, and walkways because they combine durability with timeless appeal. But sometimes, homeowners notice an issue: their once-smooth surface begins to shift or sink unevenly.
This raises the important question: What causes pavers to shift or sink? Understanding the causes—and how to prevent them—can help you keep your paved surface strong and attractive for decades.
What causes pavers to shift or sink? The Short Answer
The three most common causes are:
- Improper base preparation
- Poor drainage beneath the pavers
- Missing or weak edge restraints
Each of these factors plays a critical role in the long-term stability of your paver installation. Let’s explore them in detail.
Improper Base Preparation Explained
Inadequate Excavation Depth
If the base isn’t dug deep enough, the pavers won’t have the support needed to handle heavy loads or natural soil movement.
Wrong Type of Base Material
Using soil or sand alone instead of crushed stone creates an unstable foundation that shifts over time.
Lack of Proper Compaction
Uncompacted base layers eventually settle, leading to sunken or uneven pavers.
Drainage Problems That Lead to Shifting
Water Pooling Beneath the Surface
Standing water weakens the foundation, washing away joint sand and loosening pavers.
Soil Erosion and Washouts
Improper grading or missing drainage channels can erode the subsoil beneath pavers.
Freeze-Thaw Cycles in Cold Climates
Water that freezes and expands under the surface can lift pavers, only to have them sink again when it melts.
The Role of Edge Restraints in Paver Stability
Why Edge Restraints Are Essential
Edge restraints lock pavers into place, preventing lateral movement under pressure.
Common Mistakes in Edge Installation
Using weak materials or skipping edge restraints altogether almost guarantees shifting over time.
Long-Term Benefits of Proper Edging
Strong edge restraints protect against spreading and preserve the overall pattern of the pavers.
Other Contributing Factors to Sinking Pavers
- Heavy Loads Beyond Design Capacity – Parking large trucks on a patio designed for foot traffic.
- Tree Roots and Natural Ground Movement – Can push pavers upward or cause soil to settle.
- Poorly Installed Joint Sand – Without polymeric sand, joints wash out easily.
How to Fix Shifted or Sunken Pavers
Step-by-Step Paver Re-Leveling Process
- Remove the affected pavers.
- Excavate and re-compact the base.
- Add fresh bedding sand.
- Reset the pavers and reapply joint sand.
Tools and Materials Needed
- Rubber mallet
- Level
- Compactor
- Polymeric joint sand
When to Call a Professional
If a large area has shifted or drainage issues are severe, professional help ensures a lasting solution.
Preventing Paver Shifting During Installation
- Proper Excavation and Base Compaction: At least 6–12 inches of compacted base for driveways.
- Installing Drainage Solutions: French drains or slope grading.
- Securing Strong Edge Restraints: Concrete or durable plastic edging.
Frequently Asked Questions (FAQs)
Q1. Why do my pavers keep sinking in one spot?
Most likely due to poor drainage or a weak base in that area.
Q2. Can sunken pavers be repaired without replacing the whole area?
Yes, individual pavers can be lifted, the base reset, and then reinstalled.
Q3. How do I stop weeds from making pavers shift?
Use polymeric sand between joints to lock them in place.
Q4. Will sealing pavers prevent sinking?
No, sealing protects against stains but doesn’t stabilize the base.
Q5. Do pavers last longer than concrete?
Yes, because they can flex and be individually repaired, pavers often outlast concrete slabs.
Q6. How often should I check for shifting or sinking?
Inspect annually, especially after heavy rains or winter seasons.
Conclusion: Building a Stable, Long-Lasting Paver Surface
So, what causes pavers to shift or sink? The main culprits are improper base preparation, poor drainage, and missing edge restraints. With correct installation and routine maintenance, pavers can remain stable for 30–50 years without significant issues.
👉 The key takeaway: invest in quality installation upfront to avoid costly fixes later.
