Lintel Repair & Forming Masonry Beams
Install helical bars above openings to create or repair brick lintels, or below openings to form deep masonry beams that redistribute loads.
The Problem
Shallow or flat brick lintels can fail due to inadequate buttressing. Concrete lintels can rotate. Timber and non-galvanised steel lintels degrade due to rot or corrosion. When replacing older window frames with uPVC units, support from the frame is lost and brickwork may begin to sag and crack.
The Solution: Deep Masonry Beams
Thor Helical reinforcement bars form deep masonry beams that strengthen existing walls. Non-reinforced masonry panels are strong in compression but weak in tension and shear. The deep masonry beam is installed into the bed joint with a minimum 500mm bearing either side of the opening, spanning areas of masonry failure and redistributing applied loads.
The Solution: Deep Masonry Beams
Product Specification
- Diameter: 6mm
- Lengths: 1–10m
- Material: Grade 304 SS (316 on request)
- Min bearing: 500mm each side
- Grout: WHO-60 required
BRE Factored Load/Span Data
For 102mm & 215mm thick brickwork using 6mm Thor Helical bars encased in WHO-60 Grout (kN/m run of beam)
BRE Factored Load Data — Safety factors per BS 5628-2:2000. BRE tests were carried out using pair of 6mm Helical Bars installed in weak materials in 1:3:12 cement, lime, sand mortar to provide lower bound values
| Opening Span (m) | 0.30m depth | 0.45m depth | 0.60m depth | 0.75m depth | 0.90m depth |
|---|---|---|---|---|---|
| 0.8 | 32.8 | 32.8 | 32.8 | 32.8 | 32.8 |
| 1.2 | 21.8 | 21.8 | 21.8 | 21.8 | 21.8 |
| 1.6 | 16.4 | 16.4 | 16.4 | 16.4 | 16.4 |
| 2.0 | 13.1 | 13.1 | 13.1 | 13.1 | 13.1 |
| 2.4 | — | 10.9 | 10.9 | 10.9 | 10.9 |
| 2.8 | — | 9.4 | 9.4 | 9.4 | 9.4 |
| 3.2 | — | 8.2 | 8.2 | 8.2 | 8.2 |
| 3.6 | — | — | 7.3 | 7.3 | 7.3 |
Table Assumes:
• Compressive strength of bricks >8.5N/mm² · Horizontal shear strength >0.07N/mm²
• No slip planes (e.g. damp-proof course) within the beam
Safety factors (BS 5628-2:2000): 1.5 masonry compression · 1.5 Masonry in Shear and Vertical Shear · 1.0 steel · 2.0 serviceability
How the Beam Works
The diagram illustrates the structural principles behind the load/span data above. Two layers of helical bars are embedded into the bed joints above and below the opening, forming a deep masonry beam that redistributes the applied load safely into the surrounding masonry.
- Applied Load is carried by the reinforced beam rather than the opening below.
- Span corresponds to the opening widths in the table (0.8m–3.6m).
- Depth of Beam maps to the depth columns (0.15m–0.90m) — deeper beams carry greater load.
- Minimum 500mm bearing either side of the opening ensures load transfer into solid masonry.
Thor Helical Additional Accessories
Ø6mm Masonry Beam Bar
Standard bar for forming deep masonry beams. 1–10m lengths. Two pairs installed top and bottom of beam to form tensile/compressive faces. Grade 304 SS.
WHO-60 Masonry Grout
Required for masonry beam formation — bonds bars into bed joints to transmit forces. Used in combination with bar pairs for structural beam formation.
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 Lintel Repair & Forming Masonry Beam
BRE factored load/span tables, 6mm bar specification.
TH WHO-60 Grout
Polymer-modified, cement-based, thixotropic mortar for use in Crack Stitching, Lintel repair and Masonry Pinning Grout Ties