Just bought 2nd hand aluminium green house - Eden 8 x 10

I am pouring a concrete base for this tomorrow ... all plants will be
grown in containers/pots.

Just thinking about what/how to fit base to slab.

Previous owner has it fitted to 2x1 battens.

Thinking is that I fix 2"x2" treated wood to slab and then fit frame
to that ........ as it won't be in contact with ground, hoping it will
have a long life.
I could chamfer edges to help water shedding.

Not sure whether I would gain anything by fitting a DPC under the
timber.

Only other option would be to lay a course of bricks ... but would
seem a lot of faff.

Any better ideas.