Waterproofing protects your structure and the assets within it against damaging moisture, humidity, and floods. Although waterproofing systems account for a small fraction of the cost of an overall building project, if the wrong solution is chosen or it’s installed improperly, the costs of remediation can be tremendous.
Risk of water ingress
Usually the amount of water used in concrete is much more than is required to hydrate the cement. This excess water takes up space in the toronto concrete forming forming a network of capillary voids. This provides channels for water to penetrate the concrete when subjected to hydrostatic pressure or capillary action. The risk of water ingress is even higher when the foundation is being built at or near the water table or in areas where there is heavier soil that’s prone to carry more moisture.
Creating waterproof concrete
Waterproof admixtures are used to create waterproof concrete. The admixtures reduce the chance of water ingress by reducing the permeability and drying shrinkage of concrete.
When to use waterproof concrete
Waterproof concrete (also called integral concrete) is generally best for water retaining structures and less critical basements that are less than 10 meters deep, where soil conditions are not aggressive, and where the consequences of flooding are less severe. This includes unfinished, basic utility spaces such as car parks and workshops where some seepage and damp patches are tolerable.
Advantages and disadvantages of waterproof concrete
Low material costs and ease of application are two advantages of waterproof concrete. To produce waterproof concrete, the ready mix producer incorporates a special admixture into the concrete. The general contractor doesn’t have to worry about allowing time for waterproofing the concrete separately.
However, extra care is needed in the workmanship of concrete placement and finishing as well as the selection of raw materials when you rely on the concrete being waterproofed. Poor casting and vibration, insufficient curing of the concrete, and lower quality aggregates can result in honeycombing, shrinkage cracks, or structure cracks that will allow water to penetrate the structure. In addition, adding water to the mix while the concrete is in transit can compromise the permeability of the concrete. A good concrete mix and proper quality control are important for alleviating these problems, but challenging to meet given project budget and schedule pressures.