Pre-finished windowsill board?

[AlanD]

I'm after some pre-finished window sill board, the type with a water-proof top coating (plastic or otherwise).

It's to go in a bathroom, which currently has a glossed MDF sill which has gradually got damp and is now cracked & swollen.

I'd rather not fit another painted board (proper wood or otherwise) if I can find a suitable coated board that will be less vulnerable to damage by kids and damp.

Can anyone suggest a suitable product or supplier?

[rbel]

Most upvc stockists will have suitable lengths of plastic with a bull nose edge - the only problem is that you will need to buy a standard 3 metre length but they should cut it to your required size.