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.
Leyburn
Leyburn is a market community as well as civil parish in the area of Richmondshire, North Yorkshire, England, sitting above the northern bank of the River Ure in Wensleydale. Historically in the North Riding of Yorkshire, the name was originated from 'Ley' or 'Le' (clearing up), and also 'burn' (stream), indicating clearing up by the stream. The community boasts two markets, numerous bars, one bank with atm and also the Co-op supermarket with an atm within, and also numerous little speciality stores. Market day is Friday. It is served by regional buses that connect to Richmond, Hawes, Bedale as well as Northallerton. Leyburn has been included in the Tour de France and the 2012 Olympics lantern relay. The cyclists in Stage 3 of the Tour de Yorkshire in May 2018 took a trip through Leyburn. An electoral ward in the same name exists. This ward consists of Harmby with a total population of 2,554.