Crack Stitching & Corner Reinforcement
High-tensile helical reinforcement bars to strengthen fractured masonry — along walls and at corners — without demolition.
The Problem
Brickwork cracks due to excessive moisture and temperature differentials causing shrinkage/expansion, as well as subsidence or ground heave. Vertical cracks at corners typically occur due to expansion of perpendicular walls, leading to rotation and cracking at the junction.
Thor Helical Solution
Thor Helical Crack Stitching bars are high-tensile helical reinforcement bars introduced into the bed joint to strengthen fractured masonry. Installing bars at regular intervals enhances the wall's tensile, shear and flexural capacity. Bars are installed 500mm beyond both sides of the crack at vertical spacings of 300–450mm (every 4–6 brick courses).
Thor Helical Solution
Crack Stitching Kit
Everything needed to reconnect and strengthen cracked walls:
- • 10× 6mm Stainless Steel Helical Bars
- • 1× 3L WHO-60 Grout
- • 1× Tooling set (Grout Applicator, mixing paddle, Pointing Tool)
Product Specification
- Diameters: 5–9mm
- Lengths: 1m, 1.5m, 2m (bespoke available)
- Material: Grade 304 Stainless Steel (316 on request)
- Spacing: 300–450mm vertical (every 4–6 courses)
- Extension: Min 500mm beyond crack
Related Applications
Test Results
Crack Stitching bar range is independently tested within Lucideon to conform to BS EN 845-1:2013+A1:2016 and test method BS EN 846-4:2002 when installed using WHO-60 Grout.
Crack Stitching Bar Performance Data
| Bars/Bed Joint | Bar Diameter (mm) | Mode of Test | Mean Load at 2mm Deflection (kN) | Ultimate Load Capacity (kN) |
|---|---|---|---|---|
| 1 | 6 | Tension | 6.26 | 8.39 |
| 1 | 7 | Tension | 6.41 | 9.57 |
| 1 | 8 | Tension | 8.73 | 11.06 |
| 1 | 9 | Tension | 8.45 | 11.50 |
| 2 | 6 | Tension | 10.86 | 16.00 |
| 2 | 7 | Tension | 11.99 | 17.65 |
| 2 | 8 | Tension | 10.67 | 17.65 |
| 3 | 5 | Tension | 6.89 | 14.34 |
*Test slot depth 40mm, bar embedded 400mm within bed joint
Bed Joint Installation — Step by Step
Rake out bed joint to 40mm depth, extending 500mm either side of crack
Clear debris and flush with water to ensure grout bonds to sound mortar
Pump WHO-60 grout bead to back of slot; ~10mm from exterior surface
Insert bars spaced equally (1 bar: 20mm / 2 bars: 15 & 25mm / 3 bars: 10, 20, 30mm)
Trowel back displaced grout and re-point. Ensure full bar encasement.
Thor Helical Additional Accessories
Crack Stitching Kit — Complete
10× Stainless Steel Helical Bars + 3L WHO-60 Grout + Tooling set (applicator, mixing paddle, pointing tool). Everything needed to reconnect cracked masonry.
Ø6mm Crack Stitching Bar
Standard single-bar installation. Available 1m, 1.5m, 2m lengths. Grade 304 SS. Most common for domestic brickwork crack repair.
Ø8mm Crack Stitching Bar
Heavy-duty option for wider cracks or higher loads. Use 2 bars per bed joint for enhanced performance (17.65 kN capacity).
WHO-60 Masonry Grout
Polymer-modified grout specifically formulated for helical bar crack stitching. High bond strength, low shrinkage. Available in 1.5L and 3L packs.
Thor Helical Grout Gun
Used with different nozzles to install grout for different applications. A flattened nozzle is used for applying grout to bed joints and a pinning nozzle is used for filling clearance holes with grout.
Grout Bags
A reusable alternative to a Grout Gun, used with disposable inserts for applying grout to bed joints and clearance holes.
Downloads
Full technical data, test results and installation guidance
TH Crack Stitching
Ø5–9mm bars — test results, bed joint installation, kit contents.
TH WHO-60 Grout
Polymer-modified, cement-based, thixotropic mortar for use in Crack Stitching, Lintel repair and Masonry Pinning Grout Ties