It is a composite plastic product, polymer and wood dust. Not to be
painted with normal logic. Plastics need the proper paint products to
bond. See how the paint bonds use you finger nail or a screwdriver, does
it come off. What was it painted with, find out and talk to Timber
Tech. They may have done it right but its up to you to find out. I
would guess they used latex porch and floor paint. It wont wear well
and water may not do well on horizontal surfaces. What to put on now?
It depends on what they used.