How to Install Interlock Pavers
The complete DIY guide to installing professional-quality paver patios and walkways in Northumberland County. From excavation to final compaction, learn the techniques that ensure lasting results.
Installing interlock pavers is one of the most rewarding DIY landscaping projects you can tackle. When done correctly, a paver patio or walkway will last decades, withstand Ontario's harsh freeze-thaw cycles, and add significant value to your Northumberland County home. This comprehensive guide covers everything from initial planning through final compaction, with specific tips for our local soil conditions and climate. While this project requires physical labor and attention to detail, a motivated homeowner with basic tools can absolutely achieve professional results.
Tools & Materials You'll Need
🔧 Essential Tools
- Vibratory plate compactor - Rent from Home Depot, Cobourg Rental, or similar
- Masonry saw or wet saw - For clean cuts on border pieces
- Shovels - Square and round point
- Rakes - Landscape rake and bow rake
- Hand tamper - For tight spots the compactor can't reach
- Rubber mallet - For tapping pavers into place
- Levels - 4-foot and torpedo level
- String line and stakes - For layout and slope
- Tape measure and chalk line
- Broom - Stiff bristle push broom
- Wheelbarrow - Or rent a mini skid steer for large projects
- Safety gear - Gloves, safety glasses, ear protection, dust mask
📦 Materials (Per 100 sq ft)
- Pavers: 110 sq ft (includes 10% waste factor)
- Edge restraint: Plastic or aluminum paver edging with spikes
- Granular A gravel: 1.5-2 tons (6-inch base)
- HPB (High Performance Bedding): 0.5 tons (1-inch bedding layer)
- Geotextile fabric: 120 sq ft (optional but recommended)
- Polymeric sand: 2-3 bags (swept into joints)
📍 Local Suppliers (Northumberland Area)
- Home Depot (Cobourg)
- Lowe's (Port Hope area)
- Local landscape supply yards
- Direct from paver manufacturers
Phase 1: Planning & Preparation
Check for Utilities & Permits
Before digging, contact Ontario One Call (1-800-400-2255) to locate buried utilities. Check with your municipality regarding permit requirements:
- Port Hope: Patios under 200 sq ft typically don't require permits
- Cobourg: Check zoning bylaws for setbacks from property lines
- Brighton: May require permits near waterfront areas
Call at least 5 business days before you plan to dig.
Plan Your Layout
Mark your project area with spray paint or stakes and string. Consider:
- Slope: Plan for 1/4 inch per foot slope away from structures for drainage
- Access: Ensure you can get materials to the work area
- Pattern: Choose paver pattern (running bond, herringbone, basketweave)
- Dimensions: Plan for full pavers where possible to minimize cutting
Use our Interlock Calculator to estimate materials accurately.
Assess Soil Conditions
Northumberland County has varied soil types:
- Clay soils (common inland): May require additional drainage
- Sandy soils (near Lake Ontario): May need geotextile to prevent base migration
- Rocky areas (northern parts): May encounter bedrock requiring adjustments
Proper drainage is critical—water trapped under pavers will cause frost heave and failure.
Phase 2: Excavation
🔺 How Deep to Dig?
Total excavation depth depends on your application:
| Application | Base Depth | Total Excavation |
|---|---|---|
| Walkways (foot traffic) | 4 inches | 7-8 inches |
| Patios (furniture/entertaining) | 6 inches | 9-10 inches |
| Driveways (vehicle traffic) | 8-10 inches | 12-14 inches |
*Total includes base + 1-inch bedding layer + paver thickness (typically 2-3/4 inches for standard pavers)
Excavation Tips
- Dig 6-12 inches beyond your finished paver dimensions
- Maintain consistent depth across the entire area
- Excavate to firm, undisturbed soil
- If you hit soft spots, over-excavate and fill with compacted gravel
- Call for bin rental or arrange topsoil removal
Establishing Slope
- Use a laser level or string lines to establish grade
- Slope 1/4 inch per foot away from structures
- For large areas, create a crown in the center sloping both directions
- Use stakes marked with desired finished height
Phase 3: Base Installation (The Most Important Step!)
💡 Why Base Matters
A properly constructed base provides:
- Load distribution - Spreads weight to prevent settling
- Frost protection - Reduces heaving from freeze-thaw cycles
- Drainage - Prevents water accumulation and ice damage
- Longevity - The difference between 5 years and 25+ years of service
Step 1: Install Geotextile Fabric (Optional but Recommended)
Lay woven geotextile fabric in the excavated area, extending up the sides. This prevents soil from mixing with your base material, especially important in Northumberland's clay soils.
- Overlap seams by 12 inches
- Don't use plastic sheeting—it traps water
- Secure with landscape staples if windy
Step 2: Add Granular A Gravel
Granular A (3/4-inch minus crushed stone with fines) is the Ontario standard for paver bases. It compacts well and provides excellent drainage.
- Add in 2-3 inch lifts (layers)—don't dump it all at once
- Rake each lift roughly level before compacting
- Spray lightly with water to aid compaction
- Compact each lift with the plate compactor
Step 3: Add and Screed HPB Bedding Layer
High Performance Bedding (HPB) is 3/8-inch clear stone that doesn't compact, allowing for precise leveling.
- Spread 1 inch of HPB over the compacted base
- Use two 1-inch diameter pipes as screed rails
- Drag a straight 2x4 across the pipes to level
- Work in sections, removing pipes and filling gaps as you go
⚠️ Critical: Don't walk on or disturb the screeded HPB. Lay pavers immediately after screeding each section.
Phase 4: Laying the Pavers
Starting Pattern
- Start from a straight edge or corner
- Work from multiple sides toward the center if possible
- Lay pavers hand-tight against each other
- Don't walk on the bedding layer—work from laid pavers
- Check level frequently; tap down high pavers with rubber mallet
Maintaining Straight Lines
- Use string lines as guides
- Check every few courses with a level
- Small deviations compound—correct early
- For running bond patterns, offset joints by half a paver
Cutting Pavers
Border pieces and around obstacles require cutting:
- Wet saw: Cleanest cuts, rent from most equipment rental shops
- Masonry saw with diamond blade: Good alternative
- Hammer and chisel: For a few cuts only
Safety: Always wear eye protection and a dust mask when cutting.
Common Paver Patterns
Simple offset pattern, easy to lay, good for beginners
Interlocking 45° pattern, strongest for driveways
Pairs of pavers alternating direction, classic look
Multiple paver sizes for natural stone appearance
Phase 5: Edge Restraint & Final Compaction
Installing Edge Restraint
Edge restraints prevent pavers from spreading and maintain your pattern. Options include:
- Plastic edging: Most common, affordable, spike-in installation
- Aluminum edging: Lower profile, longer lasting
- Poured concrete edge: Permanent but less flexible
- Existing structures: Can serve as restraint where applicable
Installation:
- Place edging tight against pavers
- Drive spikes through edging into base every 12 inches
- Ensure edging is level with paver tops
- Backfill with soil to hide edging if desired
Final Compaction & Sanding
This final step locks everything together:
- Sweep in joint sand: Use polymeric sand (not play sand). Sweep dry sand into joints until full.
- Remove excess: Sweep all sand off paver surfaces.
- Compact: Run plate compactor over surface (use cardboard to protect pavers from compactor scratches).
- Re-sand: Fill any joints that settled.
- Activate: Lightly mist with water to activate polymeric sand binder (follow product instructions exactly).
Common Problems & Solutions
❌ Pavers Settling or Sinking
Cause: Insufficient base depth or poor compaction
Solution: Remove affected area, add base material, compact thoroughly, re-lay pavers
❌ Pavers Heaving After Winter
Cause: Water trapped under pavers freezing and expanding
Solution: Ensure proper drainage slope, check that joints aren't allowing water infiltration, may need to improve drainage system
❌ Weeds Growing Between Pavers
Cause: Joint sand washed out or organic matter accumulation
Solution: Re-sand with polymeric sand, maintain joint fill, spot-treat weeds with vinegar solution or pull by hand
❌ Pavers Becoming Uneven
Cause: Edge restraint failure, base erosion, or heavy loads
Solution: Check and repair edge restraints, verify drainage, re-level and compact affected areas
❌ Efflorescence (White Haze)
Cause: Natural salts in concrete rising to surface
Solution: Usually weathers away naturally over time. Can be cleaned with efflorescence cleaner if desired.
Ongoing Maintenance
Annual Tasks
- Inspect and refill joint sand as needed
- Check edge restraints for damage
- Clean with pressure washer (carefully—don't dislodge sand)
- Seal every 2-3 years (optional but recommended)
Seasonal Care
- Spring: Inspect after frost heave, re-sand joints
- Summer: Keep joints filled to prevent weed growth
- Fall: Remove leaves to prevent staining
- Winter: Use plastic shovels, avoid de-icing salts
Calculate Your Project Materials
Get precise quantities for your paver project. Our calculator accounts for waste, base materials, and edging.
Frequently Asked Questions
How long does paver installation take?
A 12x12 patio typically takes a full weekend for two people: Day 1 for excavation and base, Day 2 for laying pavers and finishing. Larger projects scale accordingly. Bad weather can extend timelines.
Can I install pavers over existing concrete?
Yes, if the concrete is in good condition without significant cracks or settling. You'll need 1 inch of bedding sand and edge restraints anchored through to the concrete. However, proper base preparation always yields better long-term results.
What's the best time of year to install pavers in Ontario?
May through October is ideal. Avoid installation when ground is frozen or saturated. Spring installations should wait until soil has dried sufficiently (usually mid-May in Northumberland). Fall installations should complete before hard frosts.
How much does DIY paver installation cost vs. hiring a pro?
DIY material costs run $8-18 per square foot depending on paver quality. Professional installation typically costs $15-30 per square foot. For a 200 sq ft patio, DIY savings are roughly $1,400-$2,400, but factor in tool rentals and your time.
Should I seal my pavers?
Sealing is optional but beneficial. It enhances color, prevents staining, and stabilizes joint sand. Wait at least 60 days after installation before sealing to allow efflorescence to escape. Re-seal every 2-3 years.