I think most of the WW2 fleet destroyers (Tribals, J's, K's, N's etc) had steel decks with some sort of synthetic covering - 'cemtex' or 'corticene', there would have been some wood areas on the bridge near to the compass platform and other instruments. The larger units (cruisers) had planked decks though in some cases I've heard this was removed to save weight or more often painted over dark grey as part of the camouflage. I think I have seen wooden planked areas on some of the small vessels (eg. HMS Bramble, HMS Royal Marine) though I would need to check photos.
Hope this is helpful,
James