Helical Beaming: Strengthening Masonry from the Inside Out

Words: Tiffany Tillema
Photos: Tillema & Sons Masonry

In the world of masonry restoration and retrofit, the goal is always the same: preserve the character and craftsmanship of historic structures while ensuring their long-term stability. But anyone who has worked on century-old brick or stone buildings knows that’s often easier said than done. Over the decades, shifting foundations, moisture intrusion, corrosion, and natural settling all take their toll. Cracks appear, lintels sag, and load paths change, sometimes dramatically.

Traditional repair methods like rebuilding sections of the wall or installing external supports can be invasive, costly, and time-consuming. In many cases, they also compromise the original aesthetic that makes historic masonry so valuable. That’s why helical beaming has become such a game-changer in restoration work. It offers a minimally invasive way to restore structural integrity from within the wall, using modern engineering that respects traditional craftsmanship.

What Is Helical Beaming?
Helical beaming is a retrofit strengthening technique that uses stainless steel helical bars embedded into horizontal slots cut directly into the masonry bed joints. These bars (sometimes referred to as helical rods or tendons) are bonded in place with high-strength, non-shrink grout, effectively creating a hidden reinforced beam within the existing masonry.

When properly designed and installed, this concealed reinforcement redistributes loads and bridges across weakened or cracked areas of a wall. Think of it as installing a tensioned skeleton inside the masonry, one that restores continuity without changing the visible face of the wall.

Unlike steel plates or external lintels, helical beams work in tension rather than compression. The stainless-steel profile provides exceptional tensile strength and flexibility, allowing the wall to handle load redistribution without rigid cracking or visible stress.

Where It’s Used
Helical beaming is ideal for repairing a wide range of structural issues found in older buildings, including:

Cracked masonry over windows and doors where lintels have failed or corroded.
Bowed or bulging walls caused by movement or settlement
Separation cracks from thermal expansion or differential foundation movement.
Arch and gable-end repairs where horizontal stresses need redistribution.
Retrofit reinforcement for structures undergoing adaptive reuse

It’s also being used more frequently in mid-century and modern masonry, where older steel lintels have corroded or expanded, causing displacement in the surrounding brickwork. In many of those cases, removing and replacing the steel would require extensive demolition, whereas a helical beam can be installed seamlessly through a much.

The Installation Process
The installation process begins with identifying the problem areas through structural assessment and crack monitoring. Once the appropriate beam position and design are determined, narrow horizontal chases, typically 25-35mm deep, are cut along the mortar joints at the designated height.

Stainless-steel helical rods are then laid into these chases in pairs, spaced a few inches apart vertically, and fully encapsulated with polymer-modified grout or cementitious anchoring compound. In larger spans, multiple beams may be tied together or anchored into sound masonry at each end to provide full load transfer.

Because the process uses existing mortar joints, the visual impact is minimal. After the grout has cured, the chases are repointed with color-matched mortar, leaving the wall's appearance virtually unchanged.

Material Considerations
While helical beaming systems are commercially available from several manufacturers, material selection and compatibility are critical. The stainless steel must meet appropriate grades (typically 304 or 316) for corrosion resistance, and the bonding grout should be compatible with the existing masonry’s permeability and compressive strength.

In historic brick, a lime-based or polymer-modified grout is often preferred to allow for breathability and movement. Testing is essential before large-scale application to prevent salt migration or incompatibility issues.

Why It’s Becoming the New Standard
What makes helical beaming so attractive to the masonry trade is its efficiency. Installation requires minimal demolition, there’s little downtime for curing, and repairs can often be completed with smaller crews. For contractors, that translates to faster project turnaround and reduced cost. For owners and architects, it means the building’s historical character is preserved while gaining new life.

In retrofit applications, the ability to conceal the reinforcement entirely within the wall gives helical beaming an edge over more visible methods like carbon fiber or steel plating. And because the system can be tailored to nearly any wall thickness or configuration, it’s incredibly versatile across both heritage and contemporary masonry systems.

Looking Ahead
As sustainability becomes an increasingly important aspect of construction, repair methods that extend the life of existing structures rather than replacing them are gaining traction. Helical beaming aligns perfectly with that philosophy, preserving embodied energy, minimizing material waste, and protecting the architectural heritage we can’t afford to lose.

Helical Beaming: Strengthening Masonry from the Inside Out

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