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.
Whitland
Whitland is a town and a neighborhood in Carmarthenshire, Wales, lying on the River Tâf. Whitland takes its name from its middle ages Cistercian abbey. The monastery pre-dates Tintern today is quite a wreck. The "white land" of the name (Latin: Albalanda) might describe the well-known Ty Gwyn (English: White House) where Hywel's parliament fulfilled, to the monks' unstained woolen capes, or to the abbey's sedimentary rock. Whitland was liquified during Henry VIII's conversion to a changed church. Much of its limestone was taken as well as used for various other buildings. The magnificent setting of the ruin and also the Abbey's format can still be viewed. An electoral ward of the very same name exists consisting of the Henllanfallteg neighborhood with a complete population of 2,272.