damp storage . Advice

My first storage is basically a large timber workshop with window bars . Security gates , inside i have metal cabinets for the product.

It Seems to be very damp....

Building is elevated off the floor a good 1ft. Guttering all round, brand new roof. So there is no water ingress at all.

Am I right in thinking more air flow through my store is needed. I.e air vents need installing