Damp / Moisture proofing bottom of shed ?

[STEVEROG]

I have built a floor / base for my new shed using 18mm WBP plywood sitting on 3" x 2" tannalised timbers. This will all be sitting on 2" thick paving slabs.

Before I put the shed onto the base I wondered if it was worth applying any sort of damp/moisture treatment to the timber and or plywood?

Any ideas?

 

[oilman]

The shed on the floor will keep it dry. Put gutters on the shed or water will splash on the ground and wet the shed.