Leakage woes: Among the most complicated rectifications of a leakage is one caused by waterproofing membrane failure.
IF you live in a high-rise building and have an inter-floor water leakage issue, you can rest assured that you are not alone. Inter-floor leakages are, without a doubt, one of the biggest problems faced by many dwellers of high-rise buildings.
Building technology has progressed over the years and we can build high-rise buildings that can withstand earthquakes with seismic engineering, be fire-resistant with comprehensive fire prevention measures and green buildings with energy and water-efficient measures. Sadly, however, we do not have any provisions in building codes to look into an issue that bothers many building owners and occupants – a water leakage.
Following my article that was published in the StarBizWeek Buyers Beware column on Aug 22, the National House Buyers Association (HBA) has been inundated with numerous emails and calls seeking for avenues and possible remedies to the problem of a water leakage.
I have been inspired to write this in furtherance to identify the remedies and rectification methods. I had to do some research and source for some practical applications.
I chanced upon a professional leakage detection contractor who has numerous credentials over and above his 15-year experience, namely, as a mold remediation contractor and an infrared thermographic inspector. He is certified in both of these. He is known as a professional in concrete repair and rehabilitation and is licensed in waterproofing applicator. He teaches Building Survey students in University Malaya and uses all types of non-destructive instruments and testing methods to detect leakages in buildings, ie, infrared thermographic inspection, endoscopic inspection, ultrasonic inspection, pressure gauge testing kits, ASTM flood test, etc.
Having interviewed him with HBA’s team of intellectuals, he seems to have answers with practical solutions. The following are excerpts of his recommendations, although these are not exhaustive.
Dampness and Investigation
In many leakages, when a plumber is invited, he will tell you that the plumbing system has failed. If you invite a waterproofing contractor, he will tell you that the waterproofing membrane has failed. In some worst-case scenarios, these contractors would make wild guesses and start hacking to detect the leak. Hacking, if not done slowly and carefully, can cause vibration and breakage to the concealed pipes and waterproofing membranes.
As a result, the findings can be distorted by the hacking itself. Contrary to the conventional methods, non-destructive testing and inspection techniques are based on science and there are a number of widely accepted standards.
Indeed, leakages are the consequences of defects; they are not the cause of defects. Thus, leak detection requires understanding of the decaying mechanism of the multiple building components that transport and discharge the water in the buildings.
In the event of an inter-floor leakage, one needs to investigate the possible cause/s of the leak by interviewing the occupants and carrying out an inspection accordingly. (please refer to the flow chart)
Rectification methods
Upon inspection by experienced contractors, defects in roofing, gutters, pipes and building parts which are exposed can be easily identified. However, in the case where pipes and source/s of the leakage are concealed within concrete structures, experience and non-invasive inspection tools are critical.
For leaks where the source is not so easily identifiable, invasion inspection which involves hacking and demolition is unavoidable. Experienced contractors should try to make a reasonable hypothesis and conduct tests with the least cost and disturbance to the occupants in the relevant buildings.
Roof
Rectification of leaky roofs is pretty straightforward. The contractor must identify cracked and misaligned roof tiles and restore them to good order. In addition, they must ensure that the timber roof support is not rotten as a result of a leak or attack by termites. Should rotten timbers be found, they should be replaced with additional reinforcement like new vertical or diagonal support.
Pipes
Leaky domestic pipes can be identified systematically with a Pressure Gauge Test. If the spot is identified, we can either seal the area with epoxy compound or tighten the leaking portion with rubber as a short-term measure. The long-term solution is a thorough replacement of leaking pipes and fittings with Sirim-accredited material.
Cracked building structure
Cracks on a building structure, which includes the roof top, wall and base, are caused by settlement and thermal shock. Thus, the cracks may move and enlarge over time, subject to settlement and weather conditions. In order to seal cracks effectively, we must cut the crack into a “V” shape and fill it up with elastic sealant which can cater to minor movements in the future.
For powdery surfaces with chipping cement caused by water seepage, an adhesion promoting sealer must be applied. Smoothened the same with new cement, allow sufficient curing (seven days) before applying a coat of weatherproof finish. However, eliminating the source/s of the leak and re-waterproofing is vital to prevent further deterioration to the wall.
Waterproofing
Perhaps the most complicated rectification of a leakage is one caused by waterproofing membrane failure. This is due to inferior workmanship and non-elastic materials that cannot cater for the building settlement and concrete shrinkage. Inspection of waterproofing failure should start with the pipes and building structure, which include the roof top, wall and base.
If all measures to inspect other factors have been taken, we can conclude that waterproofing failure is the cause of the leak. Efflorescence with water dripping slowly is some evidence of waterproofing failure. This can be found at crack lines and cavities are found. Besides, cavities also appear along the edges of the ceiling and in areas where sewerage pipes penetrate the concrete ceilings.
> This information deals with complex matters and may not apply to a particular situation. This information should not be relied on as a substitute for specialised professional advice.
Conclusion
The developers’ warranty against leaks and building defects is limited to the short defect liability period of 18 to 24 months. It does not tally with the 10-year warranty offered by the original waterproofing applicators practised in the industry.
Some wayward developers compromise the construction quality for more profits, believing they can get away with it. Thus, a collateral warranty which transfers the warranty against leaking (meaning – corresponding warranty against leakage) should be in place for the benefit of house buyers. Perhaps, it is about time the Housing Ministry implemented new laws that make it mandatory for house buyers to “inherit” the warranties from the manufacturers.
So, instead of suing developers under the latent defects law (which is costly and time-consuming in the court of law), those warranties by manufacturers should be assigned to the house buyers.
Water leakage is not rocket science. It can be solved professionally and amicably if there is cooperation from all parties involved.
In the event the building managers or service engineers do not possess the relevant competency, for instance structural defects or cracked lines, consulting engineers with the relevant expertise and experience in the best interest of the occupants would be ideal.
Chang Kim Loong, AMN, is the honorary secretary-general of the National House Buyers Association (HBA) www.hba.org.my – a non-profit, non-governmental organisation manned purely by volunteers.
Universiti Malaya department of building surveying lecturer Dr Mohamed Rizal Baharum and an expert in leakage work, Kuan You Wai, contributed to this article.
The following blogs deal with technicalities of leaking, its remedies and indoor mold as a health hazard in Malaysia.
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