How much does it cost to clean and seal interlock?

Sealing runs $1.50 to $2 per square foot plus HST, pressure washing with fresh polymeric sand $1.40 to $2.25, and re-sanding alone about $2. A full clean, re-sand and seal package typically runs $2.90 to $4 per square foot plus HST. Re-sealing every 2-3 years protects colour and keeps the joints locked.