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Crack Stitching

Structural Repair - Helifix HeliBar Remedial


The Helifix HeliBar is a helical stainless steel reinforcing bar, with substantial tensile properties, used for strengthening and stabilising masonry in both new build and remedial situations.


Helifix HeliBar Remedial

The Helifix HeliBar is a helical stainless steel reinforcing bar, with substantial tensile properties, used for strengthening and stabilising masonry in both new build and remedial situations.






Helifix HeliBars are bonded into cut slots at pre-determined levels in the masonry using Helifix HeliBond thixotropic cementitious grout, it is the composite action between the Helifix HeliBars and Helifix HeliBond that provides the core element of the Helifix Helibeam System, making it such a versatile, reliable and successful masonry repair system.


The length of the Helifix HeliBar varies depending upon the application. Longer lengths are used, normally in pairs, to form masonry beams that secure large areas of masonry, distributing the structural loads and overcoming various problems caused by foundation movement. They are also installed in the existing masonry to unobtrusively create or reinstate failed lintels. In shorter 1m lengths, Helifix HeliBars are used individually to perform reliable and permanent crack stitching.


Helifix HeliBar starts as round stainless steel wire with a typical 0.2% proof stress of 500N/mm² but after the cold forming manufacturing process that creates the helical hi-fin design, this more than doubles to around 1100N/mm². This means that Helifix HeliBar, with its relatively small diameter, provides substantial tensile properties to the masonry, particularly when combined with Helifix HeliBond grout which locks between the fins and bonds to the masonry. Consequently, the well proven Helifix Helibeam System has a variety of remedial and new build applications.



Creating or repairing flat arch lintels



Features:

  • Austenitic stainless steel helical reinforcing bars

  • Combines great axial strength with flexibility

  • Accommodates differential building movement

  • Generates high tensile strength with mortar (new build only) or Helifix HeliBond grout

  • No additional stresses introduced into the structure

  • Spreads structural loads to avoid secondary cracking



Crack stitching in a corner of a stone wall



Benefits:

  • Extremely economical compared with alternative methods

  • May remove or reduce the need for mass underpinning

  • Fully concealed once installed

  • Avoids expensive and disruptive taking down and rebuilding

  • Minimal disruption to the building’s fabric or occupants

  • Reduces the potential for cracking in shrinkable materials


Creating movement joints



Using 400mm long bars, installation is very similar to crack stitching. The bar is installed across the joint, as with cracks, but is only bonded at one end. The other end is allowed to move freely by inserting it into a sleeve which is bonded into the masonry.


Applications:

  • Crack stitching

  • Lintel repair and creation

  • Forming deep masonry beams

  • Horizontal structural restraint (when used with BowTie systems)

  • Reconnecting separated walls

  • Securing parapet walls

  • Support existing masonry when creating new openings

  • For reinforcing new build masonry

  • Creating movement joints

  • Seismic upgrades for existing masonry

  • Repairing bridges, tunnels and arches



Crack Stitching



Lintel Reinstatement



Securing Parapet Walls



Reconnecting separated walls




Installation:


Step 1

Step 2

Rake out or cut slots into the horizontal mortar beds, a minimum of 500mm either side of the crack.

Clean out slots and flush with clean water and thoroughly soak the substrate within the slot.


Step 3

Step 4

Using the Helifix Pointing Gun, inject a bead of Helifix Helibond along the back of the slot

Using the Helifix HeliBar insertion tool, push one Helibar into the grout to obtain good coverage.



Step 5

Step 6

Insert a further bead of Helifix Helibond over the exposed Helifix HeliBar, finishing 12mm from the face and 'iron' firmly into the slot using the Helifix HeliBar insertion tool.

Re-point the mortar bed and make good the vertical crack with Crackbond TE3




Products mentioned:


Helibar



HeliBond Grout



Crack Stitching Kit



Learn more about Helifix structural repair systems:


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