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.
Ferryside
Ferryside is a village in the neighborhood of St Ishmael, Carmarthenshire, Wales. It is 8.5 miles (13.7 km) south of Carmarthen near the mouth of the River Tywi. Initially a ferryboat crossing, then becoming an angling town, it has actually established as a holiday as well as retirement area. The town has its own lifeboat terminal and was the first town in the UK to switch over from analogue to digital television. Stemming as a landing-place on the ferryboat course to Llansteffan (the ferry was utilized by Giraldus Cambrensis in 1188), Ferryside established as a fishing village. In 1844 the population of the parish was 895. Much of the town created after 1852, when it became linked to Carmarthen as well as Swansea by Isambard Kingdom Brunel's South Wales Railway.