Permeable laneways and patios
Water-permeable landscaping surfaces
...roofing the joints. If weeds can't come up then water can't seep down.
To maintain permeability at this point, you'd want to go with either pure sand in the joints, or pea gravel, which as the name suggests, is gravel about the size of peas. This will fill the joint but still allow water to flow through and inhibit wee...