What is best material when replacing floorboards under WC?

[chainsaw_masochist]

A leaking WC has caused the supporting floorboards to become wet and begin to decay. I have to remove this section of flooring which measures about half a square metre. When I have cut out and removed the affected timber is it necessary to replace the boards like-for-like or is it possible to use a suitably sized piece of chipboard/WBP/fibreboard?

Thanks for any help.

 

[Alastairreid]

wbp ply would be the sensible choice for a wc!

ideally the same thickness as your existing boards.