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.
Gaerwen
Gaerwen is a town on the island of Anglesey in the community of Llanfihangel Ysgeifiog. It lies in the south of the island 4 miles (6.4 km) west of Llanfairpwllgwyngyll as well as 4 miles (6.4 kilometres) southeast of Llangefni. The A5 goes through the village, and also the A55 runs just a few hundred metres north. According to the 2011 Census Gaerwen is currently listed by the Office for National Statistics as Llanfihangel Ysgeifiog. The population of the area is 1,551. An important Bronze Age stockpile was located near Gaerwen in the 19th century. Making up 2 gold lockrings as well as 2 penannular arm bands, it is now in the collections of the British Museum. Facilities in Gaerwen consist of 4 public houses, one vehicle dealership, and also 4 churches. It is very much a town of the old as well as brand-new with 2 obsolete windmills in the north of the town as well as a modern industrial estate making up the south west section of the town. With along a primary school and a football pitch in the center of the town. There is also a fish as well as chip shop with a barber shop next door. A scientific research park on the south of the A55 Junction was opened in 2018.