HeliBar is a helical stainless steel reinforcing bar, with substantial tensile properties, used for strengthening and stabilising masonry in both new build and remedial situations.
HeliBars are bonded into cut slots at pre-determined levels in the masonry using HeliBond thixotropic cementitious grout, it is the composite action between the HeliBars and HeliBond that provides the core element of the Helibeam System, making it such a versatile, reliable and successful masonry repair system.
The length of the HeliBar varies depending upon the application. Longer lengths are used, normally in pairs, to form masonry beams that secure large areas of masonry, distributing the structural loads and overcoming various problems caused by foundation movement. They are also installed in the existing masonry to unobtrusively create or reinstate failed lintels. In shorter 1m lengths, HeliBars are used individually to perform reliable and permanent Crack Stitching.
HeliBar starts as round stainless steel wire with a typical 0.2% proof stress of 500N/mm² but after the cold forming manufacturing process that creates the helical hi-fin design, this more than doubles to around 1100N/mm². This means that HeliBar, with its relatively small diameter, provides substantial tensile properties to the masonry, particularly when combined with HeliBond grout which locks between the fins and bonds to the masonry. Consequently, the well proven Helibeam System has a variety of remedial and new build applications.
Creating or repairing flat arch lintels
Crack stitching in a corner of a stone wall
Creating movement joints
Using 400mm long bars, installation is very similar to crack stitching. The bar is installed across the joint, as with cracks, but is only bonded at one end. The other end is allowed to move freely by inserting it into a sleeve which is bonded into the masonry.
Cut slots into the masonry (typically the horizontal mortar joints), to the specified depth (typically 40-50mm) and vertical spacing (typically less than 800mm apart).
Clean out slots with a blow pump and apply HeliPrimer WB or flush with water.
Using a Helifix Pointing Gun, inject a bead of HeliBond to the back of the slot.
Push a length of HeliBar into the grout before injecting a second bead of HeliBond grout to cover. Push a second length of HeliBar into the slot, followed by a third bead of HeliBond. Repoint to match
- Crack stitching
- Forming deep masonry beams
- Tying corners and wall junctions
- Reconnecting separated walls
- Lintel stabilisation and creation
- Horizontal structural restraint
- Reinforcing new build masonry
- Providing seismic upgrades
- Creating movement joints
- Austenitic stainless steel helical reinforcing bars
- Combines great axial strength with flexibility
- Accommodates differential building movement
- No additional stresses introduced into the structure
- Generates high tensile strength with mortar (new build only) or HeliBond grout
- Extremely economical compared with alternative methods
- May remove or reduce the need for mass underpinning
- Fully concealed once installed
- Avoids expensive and disruptive taking down and rebuilding
- Minimal disruption to the building’s fabric or occupants
- Spreads structural loads to avoid secondary cracking
- Reduces the potential for cracking in shrinkable materials