When tying cracks in face brickwork these high strength bars are grouted into slots cut into mortar beds, ensuring the rein­for­cement is discreetly concealed once the mortar joint is pointed. Tensile forces are redis­tri­buted along the wall to dissipate load and minimise the risk of further cracking.

Method Statement

• Remove mortar along selected bed joints.
• Flush with clean water and bond helical bars (should extend 500mm each side of crack) into each slot using WHO-60 grout. Where several cracks in close proximity they can be stitched in tandem using one continuous bar.
• Fill and seal fissure to prevent the ingress of water
• Depth of the slots should be 30mm on single leaf brickwork and 45mm on a solid double brick wall. Thicker walls should be stitched from both sides.
• Bars should be spaced at 300mm to 450mm intervals

When repairing fractures in rendered walls the reinforcing bars can be installed directly into the brick units to bind them together and, where shear strength is an issue, to permit the use of diagonal rein­for­cement. Stitching offers a quick, easy and reliable method of restoring the structural integrity of cracked walls at cost effective prices.

Product Specifi­cations

• Helical Bars: 304 Grade stainless steel
  • Diameter: 5, 6, 7, 8 and 9mm
  • Available Lengths: 1.0, 1.5 and 2.0 metres and in 7metre coils.
  • Tensile strength: 1050-1200N­/mm2
• Bonding Grout: Polymer modified cement based formulation
  • Compressive Strength:­55N/­mm2
  • Tensile Strength: 5N/mm2
  • Flexural Strength:­12N/­mm2
  • Youngs Modulus:­13N/­mm2

As a market leader in the supply of the best retrofit rein­for­cement products in the UK, Twistfix are able to offer technical advice on crack stitching techniques that repair cracks permanently, irrespective of whether they are built from brick, block or stone. Simply call our help line to speak to a masonry crack repair expert.

• Crack Stitching Guide (PDF)
• Crack Stitching Specifi­cation (PDF)