The failure of brick or other masonry arch lintels is a serious issue but can easily be remedied with the use of helical bars. Once properly installed, these bars provide strong reinforcement to damaged lintels and give the property a new lease of life. Installation is complete in seven easy steps, which are listed below.
Helical bars are highly profiled and, extending 500mm beyond the window openings, forms tendons that represent two flanges of a beam; the upper and lower. The upper tendon is designed to seamlessly combine with the two brick courses that surround it, enhancing its compression abilities. The other tendon acts in the opposite way, significantly increasing both the tensile and flexural capacity of the brickwork or masonry.
Load capacity of reinforced brick lintel has been published by BRE in factored load tables that show it to be 2.6 tonnes for openings of up to 3.2m wide. The helical bars, which are cold-rolled, have been shown to exhibit a nominal tensile strength that is double that of rebar and four times that of epoxy glass-fibre. Compared to wound helix plate, helical bars are a massive seven times stronger. As the helical trough is deep and continuous, maximum interlock with the grout is ensured; the reinforcement accumulates progressively as more bars are added, redistributing stress forces are preventing sudden or catastrophic failure of the lintel.
We recommend thixotropic WHO60®, which is a cement-based grout featuring added polymers. SHrink-compensated, the grout effortlessly bonds the bars to the masonry, setting in and around the troughs of the helix and delivering compressive strength. This restricts any deflection of the bar when under stress load.