Is it worth repairing 15-year-old interlock or should I start fresh in Vancouver?

Whether to repair or replace 15-year-old interlock depends on the condition of the base and the extent of the problems — if pavers are settling, shifting, or have widespread base failure, replacement is usually more cost-effective than attempting repairs that won't last.

The key question is whether your interlock problems are surface-level (fixable) or structural (requiring replacement). After 15 years in Metro Vancouver's wet climate, many interlock installations begin showing their age, especially if they weren't built with adequate base depth or proper drainage for our 1,200mm+ annual rainfall.

Signs your interlock can be successfully repaired include isolated sunken areas affecting less than 20% of the surface, joint sand that has washed out but pavers remain stable, moss and weed growth in joints, surface staining or fading, and minor edge spreading where pavers have shifted slightly but the base remains solid. These issues typically cost $1,500-$4,000 to address on a 400 sq ft patio — lifting affected pavers, adding or removing bedding sand to correct levels, cleaning and re-sanding joints with polymeric sand, and installing missing edge restraints. If the majority of your pavers are still level and stable, repair makes financial sense.

Signs you need complete replacement include widespread settling where large sections have dropped unevenly, pavers that rock or shift when walked on, base material visible through widened joints, water pooling on the surface instead of draining, and organic growth (moss, weeds) covering more than 30% of the surface. These problems indicate base failure — either inadequate initial depth, poor compaction, or drainage issues that have saturated and destabilized the foundation. Attempting to repair base failure is like putting new shingles on a rotten roof deck — the underlying problem will destroy your repair work within 1-2 years.

Metro Vancouver's climate accelerates certain aging patterns that affect this decision. Our persistent moisture and mild temperatures create ideal conditions for moss growth, joint sand erosion, and organic matter accumulation. If your 15-year-old interlock was installed before polymeric sand became standard (early 2000s), it likely has regular sand that has washed out repeatedly, allowing weeds and moss to establish deep root systems that are difficult to eliminate without complete reconstruction. Additionally, many installations from that era used insufficient base depth by today's standards — 4-6 inches instead of the 6-8 inches we now specify for patios and 10-12 inches for driveways.

Cost comparison for a typical 400 sq ft patio: Comprehensive repair including releveling, new polymeric sand, edge restraint installation, and cleaning runs $3,000-$6,000. Complete replacement with proper base preparation, new pavers, and modern drainage design runs $6,000-$12,000. If repair costs exceed 60% of replacement cost, replacement usually provides better long-term value because you get a modern base, proper drainage, current edge restraint systems, and a fresh 20+ year lifespan.

The "15-year rule" for Metro Vancouver interlock: Installations from 2009-2010 were built during the transition to better installation standards. Earlier installations often lack geotextile fabric, adequate base depth, proper edge restraints, and polymeric sand — making them poor candidates for repair. Installations from 2012 onward are more likely to have solid bones worth preserving.

When to hire a professional for evaluation: Have an experienced interlock contractor assess your installation if you're seeing multiple problem areas, if water pools instead of draining, or if previous repair attempts have failed. A professional can probe the base depth, assess drainage, and determine whether the foundation is worth preserving. This evaluation typically costs $200-$400 but can save thousands in misdirected repair attempts.

The decision often comes down to whether you want a 3-5 year band-aid solution (repair) or a 20+ year permanent fix (replacement). In Metro Vancouver's challenging climate, investing in proper replacement usually provides better value than repeatedly repairing an inadequate foundation.

Need help finding an interlock contractor to evaluate your installation? Vancouver Interlock can match you with experienced professionals who understand the unique challenges of 15-year-old installations in our wet climate.

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Looking for experienced contractors? The Vancouver Construction Network connects homeowners with qualified professionals:

• Vancouver Safety Surfacing Ltd
• I love kitchens LTD
• Heilman Renovations