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Terrace Waterproofing

In India, Terrace Waterproofing has always been done with very traditional materials. Typically systems like brickbat Coba, Lime terracing or the “Mud Fuska” technique are still very much in vogue. These systems have been offering waterproofing with some insulation against heat.

Some of the problems that these systems have are:

  • Heavy loading on the slab
  • Cracks on the surface, especially in the case of brick bat coba
  • Expertise levels required for lime terracing/mud fuska are not as good as in the olden days
  • Offers more insulation rather than a leak-proof or water-tight system
  • As they age, breaking and redoing the same system is risky for the slab; cracks caused in the slab increase the problem of leakage

Structural Issues


Cause of Leakage:
  • Cracks on the top surface of slab – Injection grouting as required; large cracks repaired with URP-modified mortar
  • Cracks on the bottom of slab due to excess deflection – Structural consultant’s opinion must be taken; if leaking, can be addressed with hydrophobic PU foam injection grout
  • Cracks at column supports – Structural consultant’s opinion must be taken
  • Excess porosity in the slab, poor quality concrete – Resort to injection grouting
  • Expansion joint in the slab – Polysulphide sealant application with proper detailing
  • Inadequate design of the slab – Structural engineer’s opinion is required
  • Spalling of concrete due to corrosion in the slab – Detailed repair using cathodic protection and appropriate repair materials
  • Cracks due to differential settlement of a building – Structural and soil experts’ opinions must be taken

Non Structural Issues:

  • Slope not proper – Slope must be provided for effective water drainage
  • Inadequate rainwater pipes – Provide additional drain water pipes as required
  • Parapet wall not in good condition – Repair parapet masonry/plaster using mortar with waterproofing compounds or polymer bonding agents
  • Internal cracks, honeycombs, porosity (not visible to the eye) – Inject grout at leakage points from top to bottom
  • Mechanical installations like cooling towers, AC units, etc., on the terrace – Foundations must be examined and repaired if necessary
  • Aggressive climatic conditions – Choose and apply a suitable protective coating or waterproofing system
  • Thermal extremes – Provide insulation treatment over the waterproofing layer