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.
Isle Of South Uist
South Uist is the second-largest island of the Outer Hebrides in Scotland. At the 2011 census, it had a normally resident population of 1,754: a reduction of 64 considering that 2001. The island, alike with the rest of the Hebrides, is just one of the last staying garrisons of the Gaelic language in Scotland and the population-- South Uist's residents are known in Gaelic as Deasaich (Southerners)-- is about 90% Roman Catholic. The island is residence to a nature book and also a number of sites of archaeological passion, including one which is the only area in Great Britain where primitive mummies have been found. In the northwest, there is a projectile testing range. In 2006 South Uist, together with neighbouring Benbecula and Eriskay, was involved in Scotland's biggest-ever area land buyout.