Frequently Asked Questions

How does curtain injection waterproofing using MC-Injekt 2200 work in practice for a leaking basement in Delhi NCR, and when is it preferred over surface-applied waterproofing membranes or tanking systems?

Curtain injection waterproofing using MC-Injekt 2200 acrylic gel resin is a specialist technique for stopping groundwater ingress through concrete basement walls and floors from the inside of the structure, without the need to excavate the external face of the wall to apply waterproofing from the positive (wet) side. The technique is particularly valuable in dense urban environments like Ghaziabad, Noida, and Delhi NCR where basement excavation is physically impossible or prohibitively expensive (as is usually the case when the structure is surrounded by adjacent buildings, live roads, and underground services), and where the basement is already constructed and occupied. The principle of curtain injection is as follows: the contractor drills a grid of injection holes through the concrete basement wall at a downward angle (typically 30 to 45 degrees from horizontal, angled toward the soil-concrete interface), spacing the holes at 300 to 500 mm centres both horizontally and vertically so that the grid of injected gel zones overlaps to form a continuous, unbroken gel curtain. Injection packers (usually 10 to 16 mm diameter rubber-flanged or mechanical packers) are installed into the drilled holes, and MC-Injekt 2200 is injected through each packer using a single-component injection pump at pressures of 2 to 10 bar, depending on the required penetration depth into the soil and the permeability of the granular fill material behind the wall. The resin flows through the packer, through the concrete wall (if it is porous or cracked) and into the granular soil or fill material behind the wall, where it permeates the pore spaces between soil particles. The gel time of MC-Injekt 2200 is set before injection by adding the co-reactant in the required proportion — typically a gel time of 20 to 60 minutes is used for curtain injection to allow the resin to permeate into the soil before gelling, while a shorter gel time of 5 to 15 minutes is used when injecting into open cracks or joints where rapid gel formation is needed to prevent resin from travelling too far under pressure. As the injected acrylic gel permeates through the sandy fill and gels in place, it forms a semi-rigid to flexible gel matrix filling the pore spaces of the soil — creating a zone of low permeability (a gel curtain) between the outer water table and the concrete wall. Subsequent injection from adjacent packers creates overlapping gel zones that merge into a continuous impermeable curtain. The cured gel barrier redirects groundwater around the structure rather than allowing it to flow through the fill and through the concrete wall. Curtain injection with MC-Injekt 2200 is preferred over surface-applied crystalline or cementitious waterproofing coatings (such as MC-Nafuplan or MC-Protect 2K applied to the inside face of the wall) and over positive-side external membrane waterproofing in the following circumstances: when the water pressure against the wall is too high for surface-applied internal coatings to resist (sustained hydrostatic pressure above 5 bar or 50 metres head often exceeds the bond strength of internal coatings, causing blistering or delamination); when the structure is occupied and cannot be vacated for a long period (curtain injection is relatively rapid and non-disruptive compared to full internal tanking); when the groundwater chemistry is aggressive (sulfates, chlorides) and would attack internal cementitious coatings; and when the source of water ingress is diffuse (distributed through porous fill rather than through specific cracks or joints) and there is no single defect to target with crack injection alone. Space Arc Engineering provides technical support for curtain injection waterproofing project design, packer layout specification, and MC-Injekt 2200 supply for basement and underground structure waterproofing projects across Delhi NCR, Ghaziabad, Noida, and Uttar Pradesh.