RETAINING WALLS
RECOMMENDED EQUIPMENT:
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Pressure Washer: 4 GPM or better, 2000 PSI or better
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Pressure Washing Wand with 0 Degree Turbo Nozzle
AVERAGE CLEANING RATE:
1000-1500 sq ft per hour
IMPORTANT NOTES:
Retaining walls tend to develop a hardened white residue. This is either efflorescence or calcium deposits. In either case, pressure washing or soft washing is not a viable solution. A chemical restoration process is needed for cleaning.
RECOMMENDED SCOPE OF WORK:
Before beginning, ensure you have completed all the steps in the Worksite Preparation Guide.
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PRE-RINSE
Use a wide mouth, large orifice nozzle (like a black soap nozzle or M5 Twist) to rinse the entire surface. The goal is to clear any loose dirt or debris and to cool down the surface before pre-treating it with chemical.
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APPLY PRE-TREATMENT CHEMICALS (Optional)
Apply a 3-4% mixture will begin to break down organics and clean the concrete. Apply a even coating across the entire surface and allow 15 minutes of dwell time before rinsing.
Pro Tip: Rinse the pretreatment chemicals before pressure washing. Vertical surfaces tend to bounce chemicals back toward the technicians which can cause minor chemical burns.
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PRESSURE WASH
Use a 0 Degree Turbo Nozzle to pressure wash the surface. Move the nozzle in a slow and controlled straight line along the concrete about 4-6 inches away from the surface in a single pass. Continue this until the entire surface is complete.
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RINSE & INSPECT
Once the entire surface has been cleaned, it's time to rinse. Use partially open ball valve or a M5 Nozzle to rinse the entire concrete clean. Inspect the concrete for any missed spots, post cleaning damage, or any other defects. Use the pressure washing want to touch up these spots or reapply the surface cleaner to larger areas.