Before you clean the stains, you will need to get rid of dust and debris. This can be done using a stiff bristle brush and soapy mixture prepared using hot water. It is best to clean a freshly installed Trex deck using this technique.
Mill markings can often be seen on the side of a Trex deck. Such markings can be easily removed by rubbing alcohol over them. Rub the alcohol gently because you may end up damaging the deck if you are too vigorous. Alternatively, you can use a conventional deck wash that contains bleach in tandem with detergent.
It is important to remove oil and grease stains immediately. Clean the stains with household de-greasing agent and use hot water in order to rinse the deck.
If the stains you are cleaning are chalk markings, use hot soapy water with bleach. If the chalk markings are coloured, you will not be able to clean them. In such a situation, you will have to hide the markings with white chalk or baby powder.
Place ice cubes over the stains and sprinkle calcium chloride or rock salt over the cubes. Allow time for the ice cubes to start melting and rinse them off when that happens.
Ink stains can be best removed by first scrubbing the stained areas with hot soapy water and then rinsing thoroughly.
Rust stains and ground-in dirt can be removed from a Trex deck with a cleaning product that contains oxalic or phosphoric acid base.
It is common for a Trex deck to get pigmentation stains due to harsh weather conditions. Such stains can be removed easily using common rust cleaner.
Mix bleach in hot water, scrub the stains with it and then rinse the Trex deck in order to get rid of light wine and berry stains.