Article in English: The combination of moisture and dirt/pollen will cause mold to start growing on your deck. To prevent this, keep the surface of your deck as clean and dry as possible. Make sure your deck has effective drainage around its perimeter and between the deck planks. Your deck should have, at minimum, 6 inches (15.24 cm) between the wooden planks and the ground beneath for ventilation. This allows the water to drain off the deck and into the soil without the wooden planks being forced to sit in the soggy ground. There should never be standing water underneath your deck. If you notice standing water underneath, you may need to use a different grade of soil around your deck to improve drainage. Pollen, leaves, dirt and other debris often get lodged in between the wooden planks. It’s easy to overlook this debris since it can’t be seen by glancing over the surface. Make sure you inspect the gaps and keep the spaces between the deck boards clean and free of debris.

Summary in Indonesian:
Jaga kebersihan permukaan dek. Pantau masalah drainase. Jaga celah antara dek bebas sesampahan.