Case 1

Good Practices

Design

Ensure that there are enough thermal and expansion joints running across the slab. For expansion joints, an upturn should also be provided not less than 150mm high with metal capping [Seeley-Building Technology]. The detailing of the expansion joints should be accurate to accommodate any movement in the slab.

Construction

The width of the joint should be in accordance with BS 6093 but the maximum expansion joint width should be 300mm in trafficked areas [FOSROC manual]. Also, all dust in the joint sealing slots should be blown out with dry, oil-free compressed air. Ensure that the expansion joint filler is tightly packed into the slot. Before sealing the slot insert the backer rod caulked tightly into the base of the sealing groove to prevent the sealant adhering to the base of the slot.

Materials

Sealant should be tolerant of climatic variations and have high movement accommodation. An elastomeric sealant would be suitable for movement.