How to Waterproofing your bathroom


Waterproofing is the method in preventing the penetration of water into the building spaces. The major wet area in houses, office space, showrooms, or anywhere is bathrooms.In this article, I will show everything you need know about bathroom waterproofing in Sri Lanka.

Bathrooms are not alone a place to get fresh; it is a place of rejuvenation and refreshment. Based upon individual choice bathrooms are built. Of all other rooms in the house, the bathroom needs to be waterproofed to a maximum extinct. The whole look of the home gets disturbed when the bathroom is water penetrated. Failure in waterproofing of the bathroom may result in the loss of a good look at bathrooms. Also, it may lead to structural damage to the building. This will increase the overall maintenance cost of the building up to 30 to 35% of the total cost depending upon initial investment in the building. Hence bathroom waterproofing is the important criterion to be considered while constructing a building



  For waterproofing of the technique is cementitious waterproofing, which is the easiest way to waterproof buildings. It is the commonly used method to waterproof frequently wet areas such as bathrooms and toilets. The materials such as PVC like tape, waterproof grout, waterproof coat such as a cementitious polymer, water sealant are used.


Bathrooms and toilets require high protection against moisture. Hence composite waterproofing is preferred. In this composite waterproofing acrylic coating and tiling, the system is done using ceramic covering.


  • Surface preparations: The bathroom surface must be cleaned to make free of dust. The surface must be scrapped to make it smooth.
  • Priming of bathrooms: primer is applied with the help of roller brush up to the required height and floor of the bathrooms.
  • Bond breakers: as the primer is dried, silicon must be applied up to the required height. Silicon is applied vertically and horizontally to avoid gaps.
  • First coat of waterproofing: the membrane is applied to cover joints, sinks, shower fixtures so that all the critical areas are finished. Then the membrane should be applied to the walls and floor.
  • Second coat of waterproofing: after the first coating gets dry, a similar type of second coating is repeated by applying the membrane.


The dampness and leakages are due to the sanitary fittings that are made in bathrooms, weakening of clay material coating between the floor tiles in bathrooms, quality of plumbing materials. The following are the common defects that occur in bathrooms and toilets,

  • Structural join seepage: Low quality of material, poor application of materials leads to the seepage of structural joints.
  • Porous concrete leakage: It is due to improper design and insufficient mixing, concrete absorbs water becomes porous in nature.
  • Tile cracks: When the tiles are not soaked properly, then they lose the water-tightness over a period of time. This leads to damage by further construction activities. 
  • Rusting: Because of moisture-retaining in the floor bed results in leaching of surfaces, growth of algae, and fungi. It is due to prolonged dampness and poor ventilation.
  • Leakage at pipe penetration and joints: Without proper planning of plumbing works and lack of protection in concealed or embedded pipes, which can cause severe damage and structural defects.
  • Floor trap leakage: Floor trap is used to prevent unpleasant odor, seeping of insects into the buildings. Improper laying of floor trap so that water can seep through floors.
  • Tile debonding: because of inadequate provision or wrong detailing joints or excessive shrinkage of the substrate due to improper mixing and sufficient curing.

bathroom waterproofing in Sri Lanka


  1. joshua wienholt

    Your blog is amazing it gives so much ideas and information.

  2. Madura Illangakoon

    I am in the process of building my house in Kandy.
    Do you provide your services in Kandy?

    I need to know the cost to waterproof

    • MRC Engineering

      Yes. We are providing our service in Kandy. Pls contact us.


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