Yellow rolls are PVC waterbars (or waterstops) used to seal construction and expansion joints in concrete structures.
They create a watertight barrier within concrete to prevent water ingress in basements, tunnels, and dams.
Commonly available in Kenya in sizes such as 160mm by 30 meters, with prices typically ranging from KSh 22,000 to KSh 27,000 depending on the profile.
The material is designed to be weldable and flexible to accommodate natural movement in concrete. [1, 2, 3, 4, 5, 6]