I want to place Belgian block pavers next to a concrete slab and need some advice. Is it important to keep water out from between the slab and the pavers? Some pavers may be buried as deep as the bottom of the concrete slab.

If I do need to keep water out, what's the best way to do that? A rubber strip? Caulk? Both?

Is it a good idea to attach the pavers to the concrete with landscaping stone adhesive to keep them in place?