WHY YOU NEED TO KNOW ABOUT STRUCTURAL CRACKING AND HOW IT IS ADDRESSED
CRACKING AND FRACTURING DUE TO STRUCTURAL MOVEMENT
Cracking in walls / cracking in ground floor concrete slabs – If cracking observed is not a result of concrete cancer it may be a result of differential settlement in the ground foundation below these elements. We see these issues typically resulting from:
Poor compaction at time of construction.
‘Dirty fill’ used rather than clean, compacted sand at time of construction.
Excessive vibrations / movement from recent nearby construction
Landscaping in the adjacent area.
‘Active’ water sources in the adjacent area (such as leaking plumbing / pipes, soakwells, etc.)
Inability of elements to cope with pressures resulting from thermal expansion and contraction.
a. Minor cracks shall be repaired by chasing out with mechanical grinder, and patching with epoxy-based filler.
b. Severe cracks repaired with ‘Helifix’ wall reinforcement system. This system requires the installation of stainless steel bars embedded in the mortar joints of the wall at every 3 – 4 courses. This reinforces the wall against future cracking where substantial settlement in the foundations has stopped.
c. In order to be prevent future cracking due to on-going settlement in the area, the foundations beneath the wall may require stablisation using a variety of systems such as micro-fin grout injection prior to the Helifix being installed.