Answer
Do not sand visible composite decking without testing. Use 220 or finer only if the material allows it.
Why it happens
Composite boards have a manufactured surface that may not blend like natural wood.
Recommended grit
Avoid sanding visible composite decking unless the manufacturer allows it. Test 220 or finer in a hidden area.
Wet or dry
Dry.
Success check
The test area does not show a mismatched color or texture.
What to do
- Clean the deck board first.
- Check whether sanding is allowed for that decking material.
- Test 220 or finer in a hidden area.
- Stop if color or texture changes.
Avoid: Do not sand a visible composite deck board without testing.