Case 2
- Introduction
- Causes of Defects
- Good Practices
- Standards
- Maintenance and Diagnostics
- Remedial
- Similar Cases
- References
Good Practices
Design
It is essential for the designer to have an understanding of the effect of joint movement in order to select specifications which eliminate the risk of movement being transmitted to the waterproofing covering. Figure below shows a typical thermal joint between concrete panels which provide for adequate movement within concrete panels.
Construction
The width of the joint should be in accordance with BS 6093. 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. Correct sealant should be used to reduce sealant deterioration:
- Metal – metal = urethane, polysulfide, acrylic
- Metal – concrete = urethane, polysulfide, acrylic, silicone
- Metal – glass = silicon, urethane, polysufide
- Concrete – concrete = urethane, polysulfide, polyurethane