i’m laying a concrete base (120mm wide) which will extend approx 50mm above ground level for a 100mm wide wooden frame to sit on outdoors in the garden.

will a DPC between the two protect the tanelised wood from the damp in the concrete?

(its only a chicken run – but i have some 100mm DPC i could use

Technically the wood should be 150mm above the ground level, and should sit on a DPC. This is because anything below 150mm above GL is susceptible to getting damp from water splashing up.

To answer your question directly: Yes, the DPC will protect the wood from the moisture in the concrete, but it will still be subject to other types of moisture, as mentioned above.

It’s tanalised for a reason!

Tanalised wood is still susceptible to mould growth and surface deterioration caused by moisture.

for a chicken run it’ll be fine and use a dpc if you’ve got it.

I put a few ‘sacrificial’ strips of tanelised wood under my shed beams (at 90 degrees to the ones on the shed floor to help air circulate) – if there are any issues I can just replace them rather than the shed floor.