How To Use Power Washers On Exterior Wood

As the weather is getting better, now is the perfect time to get outside and clean any mould, algae or residual dirt from your exterior wood decking or fencing.

Power Washing Decking

Typically our customers use a power washer as the easiest option to clean their wood. This tends to be problematic due to the stresses on the wood fibres when sprayed. Wood fibres swell causing a furry type of finish. Not only will this effect the lifespan of your timber, but it can also potentially remove any coatings such as stains or paints.

We’ve recently had feedback from a client that had applied Owatrol Aquadecks on top of a softwood deck that had been laid for around 3 years. The following Spring the customer used a power washer to clean the wood and noticed that the colour was being removed while it was cleaned.

We contacted the technical team at Owatrol to discover what was happening so we could help the customer and any other clients that may require advice. Owatrol advised that the incorrect head had been used on the pressure washer – a fan lance should be used in a sweeping motion rather than an aggressive turbo head / dirt killer lance. Distance between the lance head and the wood is also important, we recommend a minimum of 30cm distance when using a power washer to prevent damage.

A better way to clean exterior timber surfaces is with a quality wood cleaner or restorer. Timber can be easily cleaned by the use of a dilute solution of Owatrol Net-trol. Promain would suggest a 1:2 dilution with water, followed by a light scrubbing. Thereafter rinsing with a hose is usually quite sufficient. Alternatively to speed up the rinsing process you could have used the power washer with a fan lance and in sweeping action.

To ensure your exterior wood lasts the test of time, combine regular maintenance with a wood cleaner or restorer such as Net-trol.  Bear in mind a power wash lance that works when cleaning your car may not be appropriate for other surfaces.

As usual, if you have any enquiries in regards your exterior wood maintenance be it for a summerhouse, deck, fence or pergola, contact our technical team for the best advice for your individual circumstance.