Waterproofing contd

Cementitious tanking
Traditional tanking methods are primarily cementitious processes. Waterproof rendering is applied to the basement walls retaining the water in the structure but away from the surface. This option is only used when the existing structure is in a reasonably good condition allowing the rendering to adhere to the surface. Some specialist companies make up their own cementitious mixes but Cemplas only uses ready mixed formulations by leading manufacturers to ensure a consistent standard of quality.

Cavity drainage
Cavity drainage is the exact opposite to traditional tanking. A flexible, vapour-proof membrane is fixed to the surface and sealed and a sump and sump pump are used to remove the water into a drainage system to storm drains. Rather than keep water in the structure, cavity drainage allows it to run behind the vapour-proof membrane system to provide a highly effective protection. Since nitrates and chlorates are hydroscopic and remain dissolved in the water, they are precipitated in the fabric of the building thus preventing any further damage. When Cavity drainage is identified Cemplas only recommend systems from leading manufacturers.

Resin injection
Resin injection is used for localised repair to stop leaks through cracks in brick or concrete. It is a lower cost treatment than tanking. The waterproof material is injected under pressure. The liquid hardens as foam and expands when in contact with water. The method is used extensively in tunnels. Cemplas, however, more usually comes to the rescue when a civil engineering contractor has used a non-specialist to apply a membrane and when it fails, asks the company to provide a reliable localised repair.

Membranes for new basements
Cemplas is approved by leading waterproofing sheet membrane manufacturers. The membrane is usually a rigid polycarbonate sheet that is fixed to the wall and floor and covered with concrete. Alternatively, a self -adhesive membrane can be used. Membranes are more economical than cementitious processes but in the wrong hands they can be problematic leading to future leaks that are difficult to control.

Deck waterproofing
To both new and existing concrete decks, such as podiums, courtyards, car park lids, balconies, flat roofs and computer floors. The membranes Cemplas use for this type of work are cold applied liquids, using spray or trowel techniques, which harden to form a tough, durable, flexible film.
The systems are buried, perhaps beneath grass / topsoil (green roofs) or under other finishes, such as paving.

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