Patio cleaner formula used by pressure washing and exterior cleaning contractors - 5L.
 
15% Sodium Hypochlorite & Surfactants.
Concentrate - this product can be diluted up to 4 parts water to 1 part solution. Test diluted product, if too weak adjust the dilution ratio.
 
How to use: Wear protective equipment, apply to surface by sprayer / brush / watering can.
Leave to dwell, once dry product will decompose, keep damp.
Rinse with water, repeat treatment if needed.
For best results pressure wash the surface prior to application.
In rare cases with bad algae growth / black spots can turn white or green/brown
after application, this should be removed with pressure washer and treatment
re-applied if needed until algae is fully gone. 
                             Warning: This product will discolour and damage fabric
 
Applications:
Sandstone
Block Paving
Imprinted Concrete
Porcelain
Render
Concrete / Flags
Resin Bound
Brick
 
Do not use on:
Tarmac
Black Limestone
Wood
 
Always test a small area first!