Injection waterproofing: characteristic features of the method

It is not infrequent that cracks appear in the foundation during its long service life, which makes it necessary to restore the concrete pad. Injection waterproofing is an efficient method for restoration of integrity of buildings’ foundations; the features of the method are described below.

Information to be taken into account by repair workers

The most commonly used materials pumped into the cracks in the concrete pad are polyurethane and acrylate gels, as well as epoxy resins and cement-sand mixtures. The waterproofing materials are injected under pressure created by powerful pumps; as a result, the mixture packs the voids by gravity. The materials can be injected not only into the foundation body, but also into the space between the concrete pad and the ground. In the latter case a waterproof membrane is created above the ground, rigidity of which depends on degree of polymerization of insulation compound.

Restoration procedure begins with the visual inspection of the building. During the inspection the repair workers identify the cracks to be packed. Then it will be necessary to drill through holes 2 to 2.5 cm in diameter with 0.5 m pitch. After that additional perforation is made in places where moisture affects the building.

Then dead-end holes of similar diameter are drilled along the crack’s line.

Metal pipes equipped with valves at the end are inserted into the produced niches. They are connected to the tank with the waterproofing material. Then the mixture is pumped under pressure into the pipes until there is a wet spot around the hole. The through holes must be equipped with protective structures to which the flow of the waterproofing material should be directed. Metal pipes with valves are to be removed only when the compound sets. Natural restriction in regard to implementation of this procedure is air temperature below 5 degrees Centigrade, which significantly reduces efficiency of the injection waterproofing use.