What Cleaners Are Safe to Use on Decking Near Water?

It’s good to see people taking a responsible attitude to their responsibilities in making sure that cleaning their decking doesn’t damage the surrounding environment. Cleaning, in particularly to stop the decking becoming slippery, should be a mixture of brushing and washing.

Causes of Slippery Decking

The slipperiness is caused by the surface deposits that cause the greening that you mention and can be a combination of mildew, moss and algae. In fact decking is no different to many other surfaces used in the garden in this regard, concrete and stone suffer from this slipperiness too.

If you have grooves in the decking this can exacerbate the problem though. Grooves are essential for draining so might well have been used for decking that’s close to water. Some people believe the grooves decrease slipperiness but this isn’t agreed universally. But grooves do make it easier for first the algae and then the moss to get a foothold and once that happens the weeds won’t be far behind.

Using a pressure washer with just water, as you have already discovered, will work and won’t damage the river, but the results don’t last for long. You need to brush the decking and scrub the railings frequently as well, to clear out any grooves and remove small debris and dampness that provide the right conditions for algal growth.

Decking Cleaning Products

There are many products on the market that will increase the effectiveness of the cleaning and prevent a build up of green growth in the future and many boast of their ecologically sound credentials. Look for a product that is bleach and acid free, organic and biodegradable for a start.

It can be tricky though. Something that declares itself safe for pets, for example, is probably safe in the sense of being licked by a cat or dog while you’re cleaning the decking. Whether this is safe when poured into a river is another matter.

As waterways rely heavily on microscopic growths as a vital part of the food chain, it is unlikely that any chemical that prevents microscopic growth on wood would be completely benign in water. A fungicidal cleaner or disinfectant should definitely be avoided.

Perhaps Better Safe than Sorry?

Unfortunately we cannot recommend any particular manufacturers, products or brand names here as this would jeopardise our impartiality, but it does look like elbow grease and water might be the safest bet in your circumstances.