My 30-year-old concrete driveway in Gloucester has deep heaves — is polyjacking worth trying at this age?

Polyjacking (polyurethane foam injection) can temporarily level heaved concrete sections, but on a 30-year-old driveway in Gloucester with deep heaves, you're likely looking at a short-term fix on a surface that's approaching replacement anyway.

Polyjacking works by drilling small holes through the concrete and injecting expanding polyurethane foam beneath the slab to lift and level settled or heaved sections. The process costs $8 to $15 per square foot in Ottawa and can restore a level surface within hours. However, the underlying cause of your heaving — Ottawa's deep frost penetration and Gloucester's prevalent clay soils — remains unchanged. The clay beneath your driveway will continue expanding and contracting with moisture changes, and frost will keep penetrating below the original base layer.

At 30 years old, your concrete driveway is also dealing with accumulated freeze-thaw damage throughout the slab. Three decades of Ottawa winters mean the concrete has endured over 1,500 freeze-thaw cycles, likely causing micro-cracking, surface scaling from road salt exposure, and general deterioration of the concrete matrix. Even if polyjacking levels the surface temporarily, the aged concrete may develop new cracks or spalling within 2 to 3 years.

Gloucester's clay soil conditions make heaving particularly problematic because the clay extends well below the frost line in many areas. Your 30-year-old driveway was likely built with minimal base preparation by today's standards — possibly just 100 to 150mm of granular base rather than the 450mm+ depth recommended for modern driveways on clay subgrade. Polyjacking can't address this fundamental base deficiency.

Consider polyjacking only if you need 2 to 3 years of additional service life while planning for full replacement, the heaved sections are isolated to small areas (under 20% of the total driveway), and the rest of the concrete is in good condition with minimal cracking or spalling. The cost should be weighed against putting that money toward a new driveway with proper base preparation for Ottawa's climate.

For a permanent solution, full removal and replacement with a properly designed base (300mm Granular B sub-base, 150mm Granular A base, geotextile fabric over clay subgrade) will cost $10 to $16 per square foot but provide 25 to 30 years of service life. Given your driveway's age and Gloucester's challenging soil conditions, replacement is likely the more cost-effective long-term investment.

Need help finding a concrete contractor to evaluate your options? Ottawa Driveways can match you with local professionals who understand Gloucester's soil conditions and can assess whether polyjacking makes sense for your specific situation.