Mould, algae and slippery decks
Black spots and green film are common on shaded Singapore decks, and a real slip risk after rain.
Why it happens
Shade, humidity and organic dirt (leaves, soil from planters) feed mould and algae. Uncapped composite and unsealed timber hold moisture on the surface, so growth comes back quickly.
How we fix it
- Composite-safe or timber-safe mould treatment and soft-brush scrub
- Low-pressure rinse, not a high-pressure jet
- For timber: sand and seal so water beads off
- Move planters onto feet so the boards under them can dry
Get it quoted
Send us photos of the affected area on WhatsApp and we will reply with a quote. More on our composite and timber deck cleaning service.
Questions about this problem
Should I pressure wash my deck?
High pressure can raise timber grain and fray composite fibres, which gives mould more places to grow. A low-pressure rinse after a cleaner is safer.
How do I stop mould coming back?
Keep the surface sealed (timber), clean twice a year (composite), and improve airflow under planters and furniture.
Other deck problems
Not sure if your deck needs a repair or a full replacement?
Send us photos on WhatsApp. We will tell you honestly whether a sand-and-oil, a few new boards, or a full re-lay makes sense, and send you a quote.