You should pull up and remove weeds by hand as and when they appear. If it is a regular problem, you might need to reseal the paving. In extreme cases, the sub layer itself may need to be re-laid. You can use weed killer, however some paving can be discoloured by stronger weed killers.
Beaumaris
Beaumaris is a neighborhood, as well as the previous county town, of Anglesey, Wales, at the eastern entrance to the Menai Strait, the tidal waterway dividing Anglesey from the shore of North Wales. At the 2011 census, its population was 1,938. Beaumaris was the port of enrollment for all vessels in North West Wales, covering every harbour on Anglesey and all the ports from Conwy to Pwllheli. Shipbuilding was a significant market in Beaumaris. This was centred on Gallows Point-- a nearby spit of land expanding right into the Menai Strait regarding a mile west of the community. Gallows Point had originally been called "Osmund's Eyre" yet was relabelled when the town gallows was erected there-- together with a "Dead House" for the remains of bad guys dispatched in public executions. Later, hangings were performed at the town gaol as well as the bodies buried in a lime-pit within the curtilage of the gaol. One of the last detainees to hang at Beaumaris provided a curse before he passed away-- decreeing that if he was innocent the four faces of the church clock would never show the very same time.