Page 22 - Surveyor 50.2 2015

PPEEEERR RREEVVIIEEWW

The Malaysian Surveyor

Figure 16: Efficient flow of water after cleaning the dirt around RWDP 2 Acknowledgment

Based on the table, RWDPs 1, 3, 5, 9, 10, 5.0 Conclusion The authors would like to express our
and 11 are categorised as having low heartfelt thanks to Universiti Kebangsaan
criticality level due to the absence of The result of this survey shows that water Malaysia [Lestari Physical Development
water ponding and the presence of dirt ponding definitely occurs on this flat roof Research Group (LPhyD) and the
level between 1 mm–25 mm. RWDPs area after heavy rainfall. Watermark signs Evolutionary and Sustainable Urban Living
2, 4, 7, and 12 have medium criticality on the flat roof slab show that water does Research Group (EvoSUL)] for supporting
due to the absence of water ponding not efficiently flow through the RWDP this research. Credit also goes to various
and the presence of dirt reaching 26 during heavy rainfall, thus causing water organisations, which facilitated the
mm–35mm. Thus, it is possible for ponding. This survey also identified that successful completion of this research.
water ponding to occur near this RWDP the presence of dirt around the RWDP
because of the high amount of dirt in serves as a crucial factor that blocks References
these areas. to the efficient flow of water from the
roof surface to the drainage. Out of 12 1. Abdul Hakim Mohammad & Wan Min
RWDP 6 and 8 are categorised as having RWDPs surveyed, two have high level of Wan Mat. 1991. Teknologi Penyenggaraan
high criticality level due to the presence criticality, namely, RWDPs 6 and 8. The Bangunan. Dewan Bahasa dan Pustaka,
of water ponding and the presence most critical RWDP is RWDP 8, which Kuala Lumpur.
of dirt reaching more than 35 mm. has water ponding and dirt level of 40
Comparing the conditions of these two mm. Hence, regular cleaning of the areas 2. Blaauwendraad, J. 2006. Ponding on
RWDPs, RWDP 8 is in the most critical surrounding these RWDPs can mitigate flat roofs: A different perspective. HERON.
level because it shows high reading of this problem. Furthermore, to facilitate Volume 51 (2/3). 151-182.
dirt height, which is 40 mm. Thus, it is real-time monitoring of water ponding in
possible for critical water ponding to these areas, sensor technology can be 3. British Standard. 2000. Gravity drainage
occur near this RWDP during heavy used even during rainfall. It is important systems inside building. Part 3: Roof
rainfall. to prevent water ponding defect, which drainage, layout and calculation. London:
can lead to serious defects on the flat roof British Standard Institution. BS EN 12056-
that, in turn, can eventually weaken its 3:2000.
structure.
4. Eldridge, H.J. 1976. Common Defects
Table 1: Criticality level of all RWDPs in Buildings. 1st. Ed. Great Britain: H. M.
Stationery Off.
No. RWDP Water Presence of Height Criticality*
ponding dirt of dirt (Low, Medium, or High) 5. Lawson, J. 2012. Roof Drainage. Not my
1 RWDP 1 near RWDP (Yes or No) (mm) problem…Maybe. SEAOC 2012 Convention
2 RWDP 2 (Yes or No) Proceedings. 136-151.
3 RWDP 3 No Yes 25 Low •
4 RWDP 4 No Yes 30 Medium •• 6. Norfatiha Hamzani, The Eco-Labeling
5 RWDP 5 No Yes 25 Low • on Sustainable Roof Materials, Master
6 RWDP 6 No Yes 35 Medium •• Dissertation, Universiti Teknologi Malaysia,
7 RWDP 7 No Yes 25 Low • Skudai, 2008.
8 RWDP 8 Yes Yes 35 High •••
9 RWDP 9 No Yes 30 Medium •• 7. Snijder, H. H. 2006. Editorial. Special Issue:
10 RWDP 10 Yes Yes 40 High ••• Ponding of Roof Structure. HERON. Volume
11 RWDP 1 1 No Yes 25 Low • 51 (2/3).
12 RWDP 12 No Yes 25 Low •
No Yes 25 Low • 8. Wijte, S.N.M. 2006. Ponding collapse
No Yes 35 Medium •• analyses of light weight roof structures by
water raising capacity. HERON. 51 (2/3):
*Criticality: 97-113.
Low •
Medium •• 9. Wilen, J.P. 2012. Still Water Runs Deep -
High ••• Proper roof slope and drainage are important
to prevent excessive water accumulation,
22 Professional Roofing, July (2012) 34 – 38.

10. Zuraida Zaini Rijal, Productivity Rate
of Roof works for JKR School Project
Scheduling, Master Dissertation, Universiti
Teknologi Malaysia, Skudai, 2010.

: No water ponding, dirt 1 mm –25 mm
: No water ponding, dirt 26 mm –35 mm
: Water ponding, dirt more than 35 mm