I’ve not washed my patio for 15 years, what can I expect with Monty?

Monty Miracle Patio Cleaner eliminates organic growth regardless of the time it’s been there, a repeat application may be needed to tackle the more stubborn areas. For example heavy Black Spot, dampen the area first, spray your solution on the affected areas and and use a soft brush to gently agitate the solution to keep it active and evenly spread, this allows your cleaner to get into every nook and cranny and will help you achieve the best uniform clean.