FLAGSTONE

RECOMMENDED EQUIPMENT:

• Pressure Washer: 4 GPM or better, 2000 PSI or better

• Pressure Washing Wand with 25 Degree Fan Tip and Turbo Nozzle

• 16" Surface Cleaner or Larger with 25 Degree Fan Tip Nozzles

AVERAGE CLEANING RATE:

1800-2000 sq ft per hour

IMPORTANT NOTES:

Flagstone and the mortar holding it together can be extremely brittle; especially at the edges. Use the unloader to relieve the pressure under 1800 PSI to minimize risk of damage. To prevent damage to the stones and the material holding the stones in place, consider the soft wash scope of work below.

PRESSURE WASH SCOPE OF WORK:

Before beginning, ensure you have completed all the steps in the Worksite Preparation Guide.

1. CLEAN EDGES

   Use a 40 Degree Nozzle (Green or the high pressure fan tip in the Jrod configuration) to pressure wash the edges of the concrete.

   If you are pressure washing concrete next to landscape, stand on the landscaping and aim the wand into the siding of the concrete. This will prevent the nozzle from blasting the landscaping and minimize damage.

   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 outline of the surface is complete.

2. CLEAR CRACKS

   Use a 0 Degree Turbo Nozzle to pressure wash joints and cracks in the concrete. This should be used to remove weeds and built up dirt. Move the nozzle in a slow and controlled straight line along the lines about 4-6 inches away from the surface in a single pass.
   
   BE MINDFUL THAT YOU DO NOT FURTHER DAMAGE ANY CRACKS IN THE CONCRETE. STAMPED CONCRETE CAN BE BRITTLE. KEEP THE TURBO NOZZLE AS FAR AWAY AS POSSIBLE WHILE MAINTAINING PRESSURE. IF YOU ARE NOT CONFIDENT THAT THE CRACK CAN BE CLEARED WITH HIGH PRESSURE WITHOUT DAMAGING THE CONCRETE, REMOVE THE DEBRIS BY HAND.

3. APPLY PRE-TREATMENT CHEMICALS

   If there are stains that need to be addressed, now is the time to do so. If degreaser is needed, apply the appropriate amount as indicated on the instructions. It's best to agitate with a stiff bristle brush and allow to dwell. Rinse and repeat if necessary.

   Another pretreatment option is a soft wash solution. A 1-3% 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 surface cleaning. Surface cleaners tend to fling water and chemicals around. These can get on your boots, legs, or pant legs causing minor chemical burns. 

4. SURFACE CLEAN

   Place a surface cleaner on one of the edges of the concrete that has been cleaned with the pressure washing wand. Engage the surface cleaner and move it forward slowly and steadily.

   DO NOT ALLOW THE SURFACE CLEANER TO REST WHILE ON. THIS CAN CAUSE CONCRETE SCARRING.

   Once a single path has been cleaned, move the surface cleaner to the next path alongside the cleaned area. Try not to overlap the cleaned area as cleaning an area twice with high pressure may remove concrete material and leave streaks.

   Continue moving the surface cleaner in straight paths until the entire surface has been cleaned.

5. 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.

6. POST TREAT

   In the final step, you may apply a post treatment soft wash solution. The 1-3% Sodium Hypochlorite, surfactant, and water mixture will continue to kill organics and brighten the concrete. Allow 1 hour of post treatment dwell time before cars or people are allowed on the concrete.

SOFT WASH SCOPE OF WORK:

If the pavers have sand and redistribution is not an option, soft washing can be a good solution instead of pressure washing.

Before beginning, ensure you have completed all the steps in the Worksite Preparation Guide.

1. APPLY SOFT WASH SOLUTION

   After the surface has been properly cleared, you may apply a soft wash solution with a pump sprayer or a dedicated soft wash system. Use a 4-6% sodium hypochlorite dilution with a medium surfactant level. 

2. ALLOW TO DWELL

   Allow the soft wash solution 15-20 minutes of dwell time. In warmer weather, the soft wash solution may dry too fast and multiple applications may be needed.

3. RINSE & INSPECT

   Once the entire surface has been cleaned, it's time to rinse. Being careful not to move the binding solution around to much, lightly rinse the surface to remove access soft wash solution. Use partially low pressure fan tip or M5 Nozzle to rinse the entire concrete clean. Inspect the Pavers for any missed spots, post cleaning damage, or any other defects. Re-apply the soft wash solution as needed. If the stains persist after two treatments, consider going to a stronger soft wash solution. Do not exceed 6% sodium hypochlorite.