Replacement Wall Tie Selection
Variations in substrate call for corresponding variations in remedial fixing techniques.Traditional brick inner and outer leaves are usually retied by mechanical expansion in each leaf.
The Mactie replacement tie comprises two parallel expander sleeves assembled on a central rod, each being set to a predetermined torque with a pre-set torque device giving fast, controlled installation at low in-place cost.
Where the inner leaf is lightweight block, or suspect material incapable of sustaining expansion stresses, secure fixing is achieved by injecting polyester or vinylester resin. It is preferred that mechanical fixing is retained in the outer leaf to allow vertical and horizontal differential movement of the walls due to thermal movement.
The SPIT Product Selector recommends the most suitable product for the site substrates concerned.
The location and density of replacement wall ties is the responsibility of the structural engineer. Site tests should be carried out to obtain actual pullout values of the selected tie in the particular site substrate.
As a general guide, ties are fixed at 900mm horizontal
centres and 450mm vertical centres, staggered to give a domino five pattern. Around openings the density is normally
increased to 300mm centres and max 225mm from opening.