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Waterproofing is done to prevent water penetration into the house. Water infiltration can lead to damages such as mould seepage, insect infestation etc. Moreover, it helps maintain indoor humidity and prevent any damage due to water exposure. When it comes to designing, the strategy is to control water movement. This is accomplished by reducing the number of the gap openings thus diverting water from the same and working on the forces acting.

To control movement means determining the building mechanism to combat, surface runoff and percolation. Building design aims to provide effective drainage for any persisting moisture that may penetrate or accumulate. Waterproofing tape creates insulation on the areas it is applied such as joints, doors, and windows. They are composed of bitumen or butyl with one side coated with aluminium foil or mineral and another side with adhesive.

Roofs are the largest parts of buildings that are exposed to rain and snow.Roof waterproofing for the buildings acts as a barrier protecting the building against rain. Therefore, roof water insulation done with the right roof insulation materials will protect the building from rain and snow by preserving the lifetime and the performance of the building. Bitumen-based waterproofing membranes are among the most well-known roof waterproofing materials.

The 3 components for any water penetration into the building are:- 

  • An opening: This can be a crack, window door or even a joint between cladding.
  • Presence of water such as rain, surface runoff, groundwater etc.
  • Forces such as gravity, surface tension, and capillary action.

Openings are an inevitable component of design. The quality of space drastically changes based on the number of openings produced. Thus some design strategies are to be adopted at the time of construction.

1. Shedding

Sloped roof for Shedding. Source

The process of simply sloping horizontal surfaces such as roofs to drain water away from the building is known as shedding. A slope of 2% is incorporated at exterior horizontal surfaces such as canopies Windows or door sill. For porous surfaces, a steeper slope is done. Modern flat roofs are also detailed to shed water to drains and gutters. A slope is induced to facilitate the same.

2. Drip

Side profile modification to facilitate drip. Source

At times depending on the material and surface runoff momentum, water tends to cling to the material underside due to surface tension. Thus to prevent the same a break is provided in the underside. This is usually sufficient to relieve the surface tension and force water to drip down the wall surface.

At roof soffits, a  variation in the height of the material on the underside of the overhang prevents water from clinging. A small grove is provided on the sill of windows for the same purpose. It is always ideal to avoid a continuous vertical or horizontal underside of the overhang.

3. Overhang

Gutter placed along Roof Overhang. Source

An overhang diverts water from the surface and sheds away from the exterior envelope of the assembly. It is taken away from the wall and is diverted onto the ground. It is a great technique to keep water away from the roof to wall conjecture.

Canopy overhangs divert water as well as protect openings. In this mechanism, it is essential to establish a collection device else it can lead to backflow or disrupt the purpose of installation.

4. Capillary Break

The process of water being able to pull itself upwards across a narrow crack is known as capillary action. It occurs in building construction when water finds narrow cracks between materials. Foundations are most susceptible to the same. 

Capillary action can be prevented by providing capillary breaks, which are materials that allow water to drain freely rather than finding cracks to seep in. Example: Gravel bases and vapour barriers under the slab. Joints between concrete pours and masonry without capillary breaks can let in water.

5. Overlap

Roof tile Overlap. Source

A strategy common in India involves overlapping materials as a shingle on vertical or sloped surfaces. The structure has mainly 2 zones, the higher element and the lower element. Due to gravity, water flows from the higher level onto the area of overlap and then to the lower material thus draining away from the building. Roof shingles serve the same purpose with the slope depending upon material porosity. Example Mangalore tiles, Ceramic roof tiles, etc.

6. Introduction of side profiles

Since capillary action also happens due to wind-driven rain.  Assuming the raindrops do not travel in a straight line, this prevents them from reaching joints thus side profiles such as grooves and sides prevent water from entering with its momentum. In interiors, water-resistant flooring and splashes are used.

  1. Porcelain Tile

The high firing temperatures and the very fine nature of clay make the tile resistant to intense water. It has an absorption rate of 0.5 per cent or less, thus making it ideal for spaces of chronic dampness.

  1. Ceramic Tiles

In comparison with porcelain, they have a higher absorption rate. Besides, these tiles are an excellent choice for areas of standing water.

  1. Sheet Vinyl

The vinyl is 100 % water-resistant and prevents water.

  1. Vinyl planks and Vinyl Tile

The lock and fold joinery style provide a light seal against water. The entire layer becomes waterproof and ranks between ceramic tiles and sheet vinyl.

  1. Bamboo Flooring

This organic material though not waterproof is water-resistant due to being heavily imbibed with chemicals and resins.

Waterproofing building assemblies is essential as it maintains longevity and provides hassle-free living.

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