Abstract:
Waterproofing is a critical aspect of building construction, ensuring longevity, durability, and
structural integrity. There are several waterproofing methods used for buildings around the
world. Among these, integral waterproofing, surface coating, and sheet membrane systems are
the most commonly used methods in Sri Lankan building projects. The prevalence of water
leakage issues in buildings throughout Sri Lanka has become a significant concern. In order to
address this problem effectively, it is essential to thoroughly investigate the causes of
waterproofing failures occurring during the various phases of a structure's lifecycle, namely
design, construction, and maintenance.
To this end, the research was conducted along three strands. Firstly, the provisions available
for waterproofing in the design standards were studied and the findings were summarised, with
the intention of promoting these among the practicing engineers and identifying any gaps that
require further research. It was found that British, Australian, Indian and European codes
provide guidelines on carrying out effective waterproofing for different parts of a structure.
Secondly, industrial professionals were interviewed during field surveys and were presented
with a questionnaire to identify the issues related to waterproofing when constructing and
maintaining the structures. Some of the key issues that were highlighted include using unskilled
laborers, not following proper procedures for waterproofing systems, high installation cost,
high cost of waterproofing materials and poorly sought joints and can lead to structural related
problems in the Sri Lankan building construction sector. As such, this highlighted the
prevailing gaps in terms of the specified standards and the existing practices. Thirdly, a
laboratory experiment was conducted to assess the performance of some of the existing
waterproofing materials available in the Sri Lankan market. A comparison of integral
waterproofing materials and surface coating materials was done based on the water absorption
test. There were 4 surface coating materials and 2 waterproofing admixtures used as integral
waterproofing materials. The water absorption test was done with oven drying procedure and
without oven drying procedure. Cementitious waterproofing material gave the best results
compared to the control cubes, in terms of the 7-day average water absorption percentage. The
bituminous coating material gave the best result after the completion of the oven drying
procedure. Overall, recommendations to improve the standards and practices of waterproofing
structures in Sri Lanka were concluded based on data collected from the three research strands.
