Cair-o-thene Backing Rods


Cair-o-thene Backing Rods are a closed-cell polyethylene back-up cord for the use in elastormeric joint sealant applications. Flexible, readily compressible, supplied in circular cord lengths.
Lightweight and moisture resistant rods for expansion joints. Easily fixed in place using glue.



Rods are available in various diameters and can be made to order
Diameter: 6mm up to 30mm


  • Readily compressed
  • Non-absorbent
  • Rot proof
  • Easily installed
  • Provides minimum strain shape for joint sealants
  • Compatible with all leading sealants.
  • Available in a full range of diameters from 6mm to 50mm.
  • Round profile enables sealant to form correct profile for optimum movement.
  • Saves money by minimising the amount of sealant required. Suitable for horizontal and vertical joints, sealing of internal wall joints, draft proofing and sealing windows.



When used as a back-up cord Cair-o-thene backing rod serves both to regulate the depth of the sealing slots required and to ensure that sealants are forced against the sides of the joint during application.  Cair-o-thene backing rod also functions as a bond breaker at the back of the seal preventing additional stress on the sealant during movement.
The diameter of the cord should be approximately 20-25% greater than the joint width, and depressed sufficiently to provide the required sealing slot dimensions. The circular sections of the backing rod cords provide a convex face giving an optimum seal configuration. They also overcome any problem of twisting which can occur with square or rectangular sections.


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