The subsequent waterproofing of building components which are not accessible due to neighboring construction or other considerations (such as tunnels, underground parking garages, elevator shafts, or concrete base slabs), is commonly carried out through the waterproofing method referred to as curtain injection. The graphic above shows an elevator shaft being subsequently waterproofed through horizontal curtain injection (underneath the concrete base slab) and through vertical curtain injection (through the walls).
A quadratic, surface-centered grid of standard packers has been drilled into the building component. KÖSTER Injection Gel G4 is injected in numerous phases through the drill holes, resulting in hemispherical areas of waterproofing on the positive (outer) side of the wall, separating the building component from ground water. For this particular field of application, KÖSTER Injection Gel G4 has received a general construction approval from the Deutschen Institut für Bautechnik (German Institute for Structural Engineering). In the case that too much material is lost through openings or large gaps behind the wall, the faster reaction of KÖSTER Injection Gel S4 may be preferred.
Curtain injection of building components with perforated bricks, bricks with finger holes, aerated concrete blocks, or double-wall constructions require the use of special gel packers. These long packers can bridge cavities within the wall and discharge the injection material into the ground on the outer side of the building component.
Always adhere to the specifications in the respective Technical Guidelines.