Waterproofing injections are perfomed with the aim of sealing a specific part of the structure or of an object, which is exposed to infiltration of water, and due to infiltration it is prone to corrosion, damages etc. Waterproofing injection is a low-cost and highly effective remedial method of enhancing watertightness of existing structures, though not eliminating the causes of problems with watertightness. This method involves using mainly acrylic resins, polyurethane resins, epoxy resins, cement suspensions, siloxane-based materials and alcali metal silicates. Injection is a perfect solution in the case of horizontal and vertical waterproofing, structural sealing of masonry, sealing of leakages through cracks, voids, expansion joints, pipe penetrations etc., as well as in the case of closing cracks and fractures, sealing cold joints while concrete pouring, repairs of masonry structures. Depending on the nature of leakage and the material of which the repaired element is made one can distinguish between low-, medium- and high-pressure injection. Proper setting of injection pressure is one of the key parameters influencing the effectiveness of conducted repair. For more details go to injections in construction industry or injections in geoengineering.