Introduction to Helical Bars in Masonry Repair: what are the many ways in which they are used?

Helical bars are high-tensile stainless steel reinforcement bars that come in a variety of diameters and lengths. Specifically, the most commonly used are 6mm and 8mm that are usually sold in either 1m lengths or 10m lengths. They are designed to restore and enhance the structural integrity of masonry. They are versatile, easy to install, and provide a discreet, cost-effective solution for a wide range of masonry issues. Their unique helical design allows for excellent bonding with grout or resin, ensuring a strong, durable repair that blends seamlessly with existing masonry.

Crack Stitch Repairs

What is Crack Stitching?

Crack stitching involves inserting helical bars into bed joints across a crack to "stitch" the masonry back together. This method is ideal for both vertical and stepped cracks in brick, block, or stone walls.

How It Works

• Preparation: The bed joint is raked out to a depth of at least 30mm, and the crack is cleaned of debris.
• Insertion: Helical bars are inserted into the prepared joint, spanning the crack and extending at least 500mm either side for optimal load distribution.
• Bonding: The bars are bonded into place using a high-strength grout or resin, which fills the joint and secures the bar.
• Finishing: The joint is repointed to match the surrounding masonry, leaving no visible trace of the repair. For an extra finish if needed, you can even use our colour matching brick repair kit to patch up any cracks or broken brickwork. 

Applications

• Restoring bond strength between separated abutting walls
• Restoring integrity of general cracked brickwork or stonework within masonry structures.

Benefits

• Restores structural integrity and prevents further cracking.
• Minimal disruption and no need for costly rebuilding.
• Suitable for both residential and commercial properties.

Read more on crack stitch repairs by visiting the comprehensive guide here

The difference between masonry beaming and crack stitching 

The key difference between crack stitching and masonry beaming is simple:

• Crack stitching will restore the original integrity of the structure and evenly distributes the load across the width of the stitch (minimising potential for cracked brickwork to reoccur). 
• Masonry beaming will enhance the integrity of the structure and give it the ability to carry the load across openings or weakened areas of ground level. 

Masonry Beaming

What is Masonry Beaming?

Masonry beaming uses helical bars to create deep masonry beams within walls, redistributing structural loads and providing additional support. This technique is often used to reinforce large areas of masonry, such as above openings or in walls affected by subsidence.

How It Works

• Design: Two sets of twin bars are installed at a minimum of 40mm bed depth, with vertical spacing of between 3-8 courses of brickwork between the sets of twin bars. Typically above windows or doors, extending at least 500mm either side of the opening.
• Installation: The bars are bonded into the masonry, creating a "beam" that spans the opening and transfers loads to the surrounding masonry.
• Load Distribution: The reinforced section acts as a composite girder masonry beam, resisting bending forces, and preventing sagging or further cracking by increasing the tensile capacity of the masonry.

Applications

• Reinforcing lintels and arches.
• Stabilising walls affected by subsidence or ground movement.
• Creating retrofit masonry beams in existing structures.

Need some more guidance and advice about spacing and specifications? Get in touch with us- we're happy to help. 

Subsidence and Ground Movement

Addressing Subsidence

Subsidence can cause significant structural damage, including cracking and sagging in masonry. Helical bars are an effective solution for stabilising walls and redistributing loads in affected areas to other areas of the structure not affected by subsidence. 

How It Works

• Identification: Cracks and areas of movement are identified, and the cause of subsidence is addressed. Most commonly, these can be:

1. Drainage issues: failed or leaking drains causing erosion of soil and foundation dropping, resulting in cracking
2. Soil movement- such as tree induced shrinkage and expansion of clay soils

• Reinforcement: Helical bars are installed in bed joints to stitch cracks and create masonry beams, providing additional support and preventing further movement.
• Monitoring: The structure is monitored to ensure stability and address any ongoing issues.

Benefits

• Non-disruptive and cost-effective compared to underpinning.
• Preserves the original fabric of the building.
• Can be used in conjunction with other remedial measures.

Window Lintel Repair

Common Causes of Lintel Failure

• Replacement of traditional timber and steel (crittal) windows or doors with non load bearing UPVC frames, shifting support and causing cracks.
• Subsidence or structural movement.
  
• UPVC window installation: read more about this by our sister company here
• Poorly designed or inadequate replacement angle steel lintels. 
• Design defects in existing lintels (such as concrete boot lintels) 

How Helical Bars Are Used

• Lintel Reinforcement: Helical bars are installed in bed joints above the window, extending at least 500mm either side. This creates a reinforced masonry beam that supports the load above the opening.
• Crack Repair: Any existing cracks are stitched using helical bars, restoring structural integrity and preventing further damage.

Benefits

• Quick and simple installation with minimal disturbance.
• No visible marks on the wall’s exterior- providing repointing is done to a good standard 
• Permanent, reliable solution for lintel repair.

Read more about window lintel repair here

Heritage Building Restoration

Preserving Historical Structures

Helical bars have been used for over 30 years for preserving restoring heritage listed buildings and ancient monuments- where preserving the original appearance and fabric of the building is paramount. Their discreet installation and compatibility with traditional masonry make them ideal for sensitive repairs.

Applications

• Crack Stitching: Repairing cracks in historic brickwork or stonework without altering the building’s appearance.
• Lintel and Arch Reinforcement: Strengthening lintels and arches in heritage buildings, often affected by age, movement, or previous alterations.
• Masonry Beaming: Creating hidden support beams in walls to address subsidence or structural weaknesses.

Benefits

• Minimal visual impact, preserving the building’s character.
• Reversible and non-destructive.
• Compatible with a wide range of masonry types and historical construction techniques.

Helical bars and grout in lime mortar 

A common misconception is that helical bar grout cannot be used in lime mortar- this is not true. Helical bars can be bonded in lime mortar structures using polymer bound non shrink grouts such as Strucsol HS Masonry Grout. 

For guidance with structural repairs on lime mortar structures, get in touch with our team, we'd be happy to help.

Practical Considerations

Installation Tips

• If you are stitching on straight brickwork, consider using our Strucsol Ultrabar Composite bar: giving you 5 times more tension and shear strength than steel.
• Follow manufacturer guidelines for bar spacing, bonding, and finishing.
• Use appropriate grouts or resins for the specific masonry type and environmental conditions.

Maintenance

• Regularly inspect repaired areas for signs of new cracking or movement.
• Address any underlying issues (e.g., drainage, soil stability) to prevent recurrence.

Conclusion

Strucsol Helical bars offer a versatile, effective, and discreet solution for a wide range of masonry repair challenges. Whether addressing cracks, reinforcing lintels, stabilising subsidence-affected walls, or restoring heritage buildings, helical bars provide a reliable method for preserving and enhancing the structural integrity of masonry.

If you need further guidance or advice, please do not hesitate to get in touch with us directly, we're always happy to help.

Or, alternatively if you are looking for someone to complete this work for you, get in touch with our trusted contracting team over at JTC Structural repairs who are Strucsol Approved and carry out works with guarantees.