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Waterproofing Your Bathroom

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In modern buildings, bathrooms are visualized as personal spaces to get refreshed and rejuvenated and as a matter of fact, a substantial amount of time and investment is put in to make-over or build bathrooms as per individual’s choice. But, the failure to correctl waterproof bathrooms hampers the look of the space as also lead to major problems.

The whole visualization gets disturbed when welldesigned bathrooms look damp and get frequently exposed to water penetration through walls, window joints, floors etc. Though wet areas occupy less than 10% of the gross floor area, the annual maintenance cost for such bathrooms area can range from 35% to 50% of the total maintenance cost depending on the type of facility.

Normally the materials and components used in bathroom to make its floor, wall, architectural finishes etc. including service pipes and sanitary fittings are susceptible to natural movement. As a result, the materials made of clay and tiles could increase in size affecting the joints and causing the tiles to shift. This results in the leakages and dampness on the walls. Wrong selection and incorrect application causes the premature failure against leakage and rectification becomes much costly and time-consuming and annoying too.

The main purpose of the waterproofing treatment is to stop the movement of water through the floor bed or moisture penetration through the walls and by drainage of the water providing proper slope to the drain points. The common defects that occur in bathrooms and toilets are:

• Seepage through structural joint because of use of poor quality material or insufficient water tightness due to poor application and main water source remains undetected and unattended.

• Leakage through porous concrete because of poor design and inadequate mixing concrete retains water and remains damp for long time.

• Cracks in tiles because if the tiles are not soaked properly and if tiles are not tapped in place, they lose their water tightness with time and get damaged by subsequent construction activities.

• Tile de-bonding because of inadequate provision or wrong detailing joints or excessive shrinkage of the substrate due to improper mixing and insufficient curing.

• Rust staining because of moisture migration and leaching of the surface and unattended algae and fungus growth on the surface due to prolonged dampness and poor ventilation.

• Leakage at pipe penetration and joints: Unplanned plumbing work creates gaps left at the junction and also when no proper protection is taken around the concealed and embedded pipes, water can seep through causing severe damage.

• Leakage through floor traps: Because of improper laying of floor trap along the slope and insufficient protection at the corner rounds or poor application of membrane around pipes, water can seep through the joints.

How to waterproof your bathroom

The complete floor with 300 mm height along the periphery wall should be covered with suitable brush applied polymer modified cementitious base waterproofing membrane. Such waterproofing is termed as ‘tanking’ and the slope is to be maintained to effectively direct all water to a drainage outlet. Before applying waterproofing membrane, ensure that no loose dust particles or oil is there on the surface as these may debond the entire film.

The waterproofing membrane should be taken 150mm along the floor up to adjacent floor area and a concrete kerb is to be provided at the doorway so that no water can escape out of that doorway. Also, corners between floors and walls are to be rounded with water tight polymer mixed cement sand systems and then a thick cement sand mortar is to be laid over the waterproofing membrane before laying of embedded pipes.

Pipe joints should be well protected with waterproofing tape wrapped around them and floor bed is made. Any pipe insertion and floor traps should be sealed at joint and encased with waterproofing tape. Waterproofing membrane is then applied on the walls up to a height of minimum 1800 mm and width of 1500 mm at shower areas before. The membrane must be elastic enough so that it should accommodate the movements.

Before putting tiles on the floor, a water penetration test is to be carried out to ensure water tightness. Tiles are to be placed using polymeric tile adhesives and the joints are to be filled with tile joint filers so that no water can seep through them. Ensure to follow the technical instructions and product manuals properly to achieve water tightness.

The best way to maintain your bathroom tiles is to prevent them from fungus, ants & bacterial attack. Always use a grout for filling tile joints in kitchen and bathroom areas which is stain resistance, antibacterial, noncracking and above all should be CFTRI approved for its food grade quality. The tile joints should be installed with gap of min 2mm. This gap should be sealed with Roff Rainbow tile mate epoxy (Available in 22 colours) – a permanent, waterproof joint filler that sustain temprature upto 1000C, chemical resistant & bateria proof. It is best to get advice from us to what type of product is best for your type of tile quality & design.

To prevent leakages in dry walls and to protect warter splash areas, use waterproof adhesive beneath tiles and do not adhere it with cement. Cement tends to get settle and hence cause cracking of tiles, hollow sound and debonding. Tiles should be adhered with a 100% waterproof adhesive that can even work underwater and avoid harsh chemicals on tiles to
remove stains or dirt and maintain the shine. Use specially made cleaners to clean the tiles & ceramic ware e.g. wash basin. Its pH is well balanced to remove those tough stains of hard water & paint & keep the floor looking like new.




Sanjay Bahadur
Global CEO
Construction Chemicals
Pidilite Industries


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