Helifix CemTie

CemTie is the default specification on TRSC heritage masonry remediation projects where in-plane and out-of-plane wall continuity must be re-established without visible surface alteration. Its principal advantage over through-bolted alternatives is heritage compatibility: there is no plate, no nut, no resin smear visible on the external face after grout pointing. Heritage Queensland and equivalent authorities in NSW and VIC accept CemTie installations under heritage consent frameworks subject to evidence of structural adequacy and reversibility. The most common specification pitfalls TRSC encounters are (1) tie length selection — the tie must extend through both leaves of cavity-wall masonry and engage the inner leaf by at least three brick courses; selecting a tie that bottoms out in the cavity provides no load transfer; (2) grout selection — only Helifix HeliBond (or a HeliBond-equivalent polymer-modified cementitious grout) provides the mechanical interlock with the helical tie profile; substituting a generic non-shrink grout reduces pull-out capacity by typically 60-70%; (3) drilling through bed joint vs. brick — the standard installation drills through the bed joint to preserve the brick face, but on stretcher-course brickwork or where bed joint mortar has been previously repointed with hard-cement mortar, drilling through brick may be required and the engineering check changes. TRSC specifies tie diameter, tie length per location, drill orientation (perpendicular to the wall plane vs. inclined for crack stitching), grout material, and a pull-out testing regime per AS 3700 Appendix A. Site inspection includes witness of the first 5% of installations, pull-out test verification at agreed frequency, and photographic record of each tie position correlated to a wall elevation.