1. Ensure adequate ventilation under and between decking boards to prevent mould growth.
2. Improve drainage or grade soil to eliminate standing water under decks. Direct downspouts, downspout extensions and splash guards away from composite decks.
3. Keep your composite deck dry. Standing water overtime could stain your deck
4. Clean your composite deck as often as needed, at least twice each year. If you decide to use a pressure washer, use extreme caution and use at pressures less than 2,500 psi at 12” above the deck surface.
5. Keep debris out of gaps between the decking boards to ensure proper drainage. Dislodge accumulated dirt with a broom or by using soap, water and a scrub brush, scrubbing in the direction of the grain pattern.
6. To remove tar or asphalt, use Citrus Solution. Be sure to follow the manufacturer's recommendations.
7. For oil and grease stains, speedy clean up is the best. The longer the oil or grease sits on the surface the most likely it is to soak into composite wood fibres. If soap and water don't do the trick, test an inconspicuous area using a cleaner.
8. Use polypropylene or colourfast woven rugs on your composite deck only. Any mat with a rubber, vinyl or latex backing could mark your deck. Although the marks can usually be removed, we recommend avoiding these materials.
9. Never use shovels or sharp edges to remove snow and ice from your deck. Never use sand either. Instead, use a calcium chloride-based “ice-melt” or rock salt. Do not use ice melt with an added colourant. The dyes can stain your composite decking.
Article reference source: http://diyonlinemag.com/product-news