Accommodation is one of our basis necessities. Houses make up the biggest portion in our investment and assets that we have been working for throughout our life for the enjoyment of ourselves and our family.
Protecting our houses is always our major concern. However, fire, water, Act of God and tempests are perhaps the most detrimental threats to the safety of the physical structure and appearance of our houses. Are you aware of the fact that according to Micheal T. Kubal in his book, Construction Waterproofing Handbook, water damages more structures and building than wars collectively. (Page 1.1)? Indeed, WATER, although overlooked in most cases, is the key component that bring damages to our houses and disturb the peace in our mind.
The author is a maintenance contractor with specialization in finding leak. He is a licensed applicator in waterproofing and structural repair, a certified mold/ fungus remediation contractor, an experienced plumber and a building envelop coating contractor. Now, he would like to share his experiences and knowledge in the how water can damage our houses. The scopes covered include sources of leaking, impact, laws/ regulations and the various type of solutions to cater for different conditions.
To contact him, you may call 016-2185196 or send an email to him at firstname.lastname@example.org.
1) Sources of Leak/ Water Intrusion
- Roof tiles – Misaligned roof tiles either caused by stepping or strong wind
- Concrete flat roof – Failure in Waterproofing Membranes or Damp Proof Course
- Flashing – Improper installation, short flashings and peeling sealant
- Cracked building envelop – Shrinkage during the curing of concrete structures and plastering, thermal shock and soil settlement that cause cavity
- Condensation – Thermal leakage and Dew Point
- Leaking Toilet Slab – Cavity and Waterproofing Failure
- Pipe leaking – Different lifespan of various piping materials, blockage, breakage and wear and tear
a) Domestic water pipes
b) Waste water pipes
c) Rain Water Down Pipes
d) Air Conditioner Pipes and/or ducts
- Rising dampness – capillary suction of water from ground or damp spots (toilets, balconies, and places exposed to water) via porous materials in anti gravity direction
- Improper design of windows/ doors that allow water to seep or stay at the windows/ doors
- Detached construction joints
- Flood and/ or storm
2. Impact of Leaking
Leaking causes damages to the authenticity of the building and its structures. In addition, it causes inconvenience and unhygienic living condition to the occupants.
Surfaces with water seepage can be easily identified with the evidence of peeling paint, rusty reinforcement steel bars, chipping cement, fungus and efflorescence. All these signs of leaking are awful and they can negatively affect the authenticity of the buildings.
Seepage of leaking water to the cement rendered surfaces and concrete structures causes exposure of the various chemical components in the cement, binder and reinforcement steel bars to oxidation. Such incident is known as waterproofing failure which can be viewed with the evidence of efflorescence. The efflorescence is indeed the Calcium Oxide derived from the chemical reaction of the Calcium Hydroxide in the lime (in the cement) and water. When the Calcium Hydroxide encounters water, it will be dissolved, carried away and emerges on the surface with least resistance or flows down together with the water due to gravity pull below the concrete slab. When the water evaporates, the Calcium Oxide will appear in crystallized form as efflorescence. Please be reminded that Calcium Hydroxide serves as a “binder” to hold masonry compound in the RC structure. Loss of such ingredient in considerable quantum overtimes (perhaps a decade or two) will cause the loss of the inherent strength of the cement concrete. Furthermore, water seepage to the reinforcement bars causes corrosion to the steel which in turn reduces the strength to the RC structures. Such a situation is known as “Concrete Cancer”.
Dampness, if stay within a building, will accumulate and effectively increase the Relative Humidity (“RH”). Should the RH exceed 60%, fungus, bacteria and other microorganism will thrive on surfaces with conducive environment for germination, i.e. on carpet, wall paper, drywalls, timber cabinets. Such unhygienic condition is detrimental to people with low immune system and allergenic respiratory symptoms. Foul odour produced by such microorganism also produces another health hazard to the occupants.
Leaking pipes especially pipes for domestic consumption, if unattended, causes water meter to run 24/7 and financial loss continously. The running water also cause soil corrusion which will destabilizes the building structures eventually.
3. Laws and Regulations
Strata Title Act 1985 and Building and Common Property (Maintenane and Management) Act 2007
Strata Title Act 1985 stipulates that the Parcel Proprietors have the duties to keep their Parcel in good repair and maintenance. On the other hand, the Management Corporations or JMBs have the duties to repair and maintain facilities in the common areas used collectively by other occupants within the same building. These facilities include roofs, external walls, common walkway, pump rooms, rain water down pipe, main domestic water and waste pipes, tanks, pool, etc. Looking to the complexity various sources of leaking, we can find rain water down pipes and waste pipes in our toilets which many Management Corporations disclaim their liability.
Common Laws – Duties of Care
In the event of leaking floor slab, the occupants who suffer from the leak occasionally encounter uncooperative neighbors in the Upper Units who refuse to carry out proper rectification work. In order to assert the right of the victim under the Common Laws – Duties of Care but such litigation process is both costly and time consuming.
Uniform Building By- Laws 1984
Local Councils have the duties to ascertain all Building Codes including Piping, Drainage and Damp Proof Course (BS 743) is properly constructed before issue of Certificate of Fitness. However, little is known to the public particularly in Malaysia about such rights and the enforcement of such duties is questionable.
Industrial Practice for 5 to 10 years Warranty by Applicator
It is a common industrial practice in waterproofing industry that the Applicators warrant 5 to 10 year limited warranty for new projects. However, too few house buyers can identify the applicator and assert their right for such warranty. The issue will become more complicated when the main contractor has left the site or Developer has passed the management right to the newly formed Management Corporation or JMB under the Strata Title Act 1985 or Building and Common Property (Maintenance and Management) Act 2007.
Short Defect Liability Period (“DLP”) by the Developers
DLP is the period where the Developer will rectify any identifiable defect launched by house buyers when they hand over the houses to the buyers. It normally last for 12 to 18 months in Malaysia. However, sign of dampness for failed waterproofing membranes in toilets and concealed pipes normally will be visible after a year or two. Thus, short DLP represents a loophole where the Developers avoid their liability after the said period.
Looking of the analysis of various Laws, Regulations and Industrial Practices related to the leaky house, house buyers are always at the losing end.
4. Rectification Methods
Upon the inspection by experienced contractors, defects in roofing, gutters, pipes and building parts which are exposed can be easily identified. However, in the cases where pipes and damp proof course which are concealed inside the concrete structures, experiences and none invasive inspection tool is critical. For leaking with unidentifiable sources, invasion inspection which involves hacking and demolition is unavoidable. Experienced contractors should try to make reasonable hypothesis and conduct tests with least costs and disturbance to the occupants in the relevant buildings.
Rectification of leaky roofs is pretty straight forward. The contractor must identify cracked and misaligned roof tiles and restore them in good order. In addition, they must ensure that the timber roof support is not rotten as a result of leaking water or attacked by tempests. Should rotten timbers are found, they should replace them with additional reinforcement like new vertical or diagonal supports.
Leaking of domestic water pipes can be identified systematically with Pressure Gauge Test. If leaking spot is identified, we can either seal the leak with epoxy compound, tighten the leaking portion with rubber as short term measures. The long term solution is a thorough replacement of leaking pipes and fittings with materials accredited by the SIRIM.
Cracked building envelop
Cracks on building envelop are caused by settlement and thermal shock. Thus, the cracks may move and enlarge overtimes subject to settlement and weather condition. In order to seal crack effectively, we must cut the crack into “V” shape and fill up the cracks with elastic sealant which can cater for minor movement in future.
For powdery surfaces with chipping cement caused by water seepage, adhesion promoting sealer must be applied, smoothened the same with new cement render layer, allow sufficient curing (7 days) before application of weatherproof finish coating. However, elimination of the leaking sources and re-waterproofing is vital to prevent further deterioration to the wall in future.
Perhaps the most complicated rectification of leaking caused by waterproofing failure. Inspection of waterproofing failure should start with the inspection of various pipes and building envelop. If all measures have been taken to inspect other factors are completed, we can reach a conclusion that waterproofing failure causes the leak. Efflorescence with water dripping slowly is some evidence waterproofing failure. This can be found at crack lines and cavity is found. Besides, it also appears along the edges of the ceiling and around the areas where sewerage pipes penetrate the concrete ceilings.
There are four (4) common methods in rectifying waterproofing failure, namely Polyurethane Grouting (Chemical Grouting), coating, membranes and penetrable sealant. In addition, different materials can be used particularly in the coating and penetrable sealing methods. Each of these methods has their respective strengths and weaknesses.
Polyurethane Grouting involves drilling, installation of mechanical packers and pumping of chemical. For concealed areas, the packers are normally left undetached. However, for exposed areas, the packers can be removed overnight, seal and touched-up. The warranty is normally one (1) year at the area of injection with radius of 6 inches only. Since the cured polyurethane hardens overtimes, it does not provide elasticity to bright future crack. Moreover, Polyurethane Grouting fill the crack without removal of the leaking sources can cause build-up of water in other areas where leak will appear later on.
Coating systems comprise of methods and materials of different type like Cementitious, Bituminous, Polyurethane and Acrylic. Each material has their respective strengths and weaknesses, too. Before application of coating, angle fillets with width and height of 25mm must be installed to avoid sharp edges. All cracks and gaps must be filled up with engineering repair mortar or None Shrink Grout. Then, subject to the conditions and locations, one must choose a system that is economical and able to cater for the threat the integrity of the system. For instance, rooftop which is exposed to thermal factor, wind and water corrosion and settlement requires elastic and weatherproof system. Polyurethane coating is suitable but it is the most expensive coating materials compared to its rivals. Bituminous or cementitious system is sufficient for toilets but cementitious system is not flexible enough to bridge any crack.
Torched bituminous membranes are used in flat concrete rooftop. A layer of bituminous coating is applied before torching and installing the membranes. The uniformity of thickness is the most important advantage. However, the lapping joints post potential failure because it will peel off overtimes due to the degradation by ultra violet and thermal shock.
Penetrable Sealer is the latest product in waterproofing where the products are allowed to penetrate the masonry surfaces and concrete compound. The depth of penetration is subject to the porosity of the concrete. The major advantage of such products are no hacking is needed in tiled areas. However, it does not possess the elasticity which is important to cater for cracks in future.
There are Laws that allow us to assert our rights with regards to leaky houses. The author has spent a great deal of time to look into these issues and has got a handful solutions for you, both in the technicality and legality.
Due to the complexity, please contact the author at 016-2185196 or email at email@example.com and let him know more about your condition so that we can share ideas and exchange opinions. A site inspection can save a lot of time for this purpose…