Waterproofing & Insulation of RCC Building Roofs

Buildings across India – homes, apartment buildings, office buildings, small workshop complexes (industrial galas), malls, hospitals, schools and other such civil structures have roofs cast in concrete. These roofs are waterproofed using many methods – brick bat coba, chemical waterproofing, wet applied membranes, APP membranes, EPDM membranes, spray applied membranes and so on. The selection of method of waterproofing depends on cost, expected service life, contractor experience, architect specification and finally the choice of developers / builders. Most of the times, these roof terraces are used for housing utilities – water storage tanks, lift systems, air conditioning units, heating units – with limited foot traffic.

With unavailability of skilled labour and demand for faster construction pace, several construction sites, today, suffer from poor workmanship, lack of supervision, resulting in waterproofing problems. Reinforced concrete, to begin with is porous and can have several capillary tracts inside the cast slab. Coupled with lack of skill – poor mixture of chemical system in the concrete or un-supervised addition of integral waterproofing compounds leads to improper waterproofing. Cracks develop over time, leading to water seepage throughout the slab, passing into walls, corroding the steel reinforcements.