New shed

I’m currently finalising the details for a new steel portal shed to be used as a secure lockup for telehandler, quad bike, trailer, a car which isn’t used much, workshop area as well as general storage in cardboard boxes. Construction will be fibre cement roof with roof lights, box steel profile sides but with one cement panel all the way round for security. I really want to keep vermin out of this shed, the weak spot will be where the box steel profile sits over the top of the cement panel, this is the fabricators current proposed method. Can anyone make any suggestions please? Or have any experience to offer. Thank you.

Thank you very much both of you, I can see how these would work and know what to ask for now, thank you.