Wall Tie Replacement
In properties with cavity walls, wall ties must be used to connect the two leafs together. In older properties, or properties that were built incorrectly, additional wall ties or replacement wall ties may need to be added.
During the 1970's, a report established that "fish tail" wall ties only had a life expectancy of 30 years and "butterfly" wall ties only had a service life of 15 years. Following this report, new wall ties were developed as a remedial measure. Expansion wall ties were found to induce additional stress into masonry and rebar was forbidden after it was established that a flexible wall tie should be used to allow for natural building movement.
To replace wall ties, we use Target Fixings' Dri Flex or Retro Flex ties, which conform to the guidance issued in BRE Digest 329 and the more recent BRE Digest 401. These stainless steel wall ties can be installed with very little disruption to the structure and usually only require access to the outer leaf.