Twistfix

Remedial Wall Ties for Existing Walls

The failure of wall ties compromises the structural integrity of a building, leading to severe problems from cracking and bowing to complete collapse in stormy conditions.  It is a common problem in the UK, as it is wherever cavity walls feature in existing construction and requires installing remedial wall ties to correct.  A comprehensive collection of these crucial retrofit components is available from Twistfix.  This blog edition looks more closely at three primary types of replacement wall ties for the remediation of existing walls.

Helical Wall Ties

Stainless steel wires are work-hardened through the production processes that form helical wall ties.  The wire deforms into a cruciform-like shape through a series of cold-rolling processes.  Subsequent twisting gives the roll-profiled wire its helix form.  This type of tie anchors the inner structure of a building to its outer wall.

Helical ties are driven into pilot holes using light blows from an SDS hammer drill fitted with a setting tool.  Following the angle of its helix, the tie corkscrews into blockwork, concrete or brick, its helical fins undercutting threads into the masonry.  A precise undercut provides a mechanical interlock anchorage, gripping the masonry firmly on either side of the cavity.  The innovative precise-helix design maximises grip and offers multiple drip points, ensuring that no water can migrate across the tie and cause damp issues.

Mechanical Wall Ties

Also made from strong, corrosion-resistant stainless steel, mechanical wall ties are partly-threaded studs equipped with expanding mechanisms at both ends; these mechanisms comprise radially-expanding sleeves operated between a set of washers and nuts.

To install the mechanical wall tie, push it into a pre-drilled clearance hole and tighten its torque nut.  The nut rotates the tie bar and squashes the neoprene sleeve between the washers and nuts at the tie's far end.  As the compressing sleeve radially expands, it creates a tight grip on the wall within the masonry.  Once setting the distal anchorage, the torque nut moves down the bar and squeezes the neoprene sleeve at the other end.  A drip ring located in the bar's central portion prevents the passage of water across the bar.

Resin-Fix Wall Ties

Stainless steel pins with significant deformation combined with cementitious brick adhesives or resins create a lasting bond in cavity wall masonry.  Installation begins by drilling a hole through one wall and into the backup material, then removing dust and debris from the bores by blasting with compressed air.  Next, inject a bonding agent into the remote-leaf bore before pushing the bar into the brick adhesive.  Once the bonding agent has fully set, dispensing a further dose of resin around the buried section of the tie in the near most leaf completes the anchoring process.

Twistfix supplies a comprehensive collection of remedial wall ties for exiting walls, many of which can be bought as part of a kit to enhance cost-effectiveness. Please browse our website to discover our complete collection of remedial wall ties, where you will also find a professional guide to wall tie replacement. If you need further information or advice, please get in touch with a member of our expert technical team.

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