20 Sep 2026

Kev Elliott
Owner Aspen Exterior Cleaning and Restoration

If your patio suddenly feels much more slippery once the weather turns, there is usually a simple reason.
Autumn brings more moisture, less sunlight and plenty of organic debris. That creates ideal conditions for algae and other organic growth to develop on paving, particularly in shaded areas.
The result can be a green or dark film across the surface that is not only unattractive but can become extremely slippery when wet.This is particularly common on patios surrounded by trees, north-facing areas and sections that remain damp for long periods.
Cleaning before winter can help remove that build-up and improve the appearance of the area, but the method matters.
Not every patio should simply be attacked with maximum pressure. The type of stone, the condition of the pointing and the age of the surface all need to be considered. Excessive pressure can damage softer materials or disturb joints unnecessarily.
At Aspen, we assess the surface first and then choose the most appropriate cleaning method and treatment. Sometimes pressure washing is ideal. Sometimes a gentler approach combined with the correct product gives a better and safer result.
The aim should always be to clean the surface properly without creating another problem in the process. So if your patio is starting to turn green or feels slippery underfoot, do not wait until the middle of winter to think about it. A little attention now can make the area cleaner, safer and much easier to maintain through the wetter months.
If you are unsure what your patio needs, we are always happy to give straightforward advice before recommending any work.


