What it is
The Sikadur-Combiflex® SG system is a high-performance joint-sealing system for construction, expansion and connection joints, and for sealing cracks in concrete structures. It consists of a flexible waterproofing tape of modified flexible polyolefin (FPO), 1.0 or 2.0 mm thick, bonded to the structure on both sides of the joint with a Sikadur® epoxy adhesive. The tape’s advanced-adhesion surface bonds directly to the epoxy without on-site activation, adheres to dry and matt-damp concrete, and remains permanently elastic — so the sealed joint can accommodate significant, repeated movement in multiple directions while staying watertight. The system is chemically resistant and is approved for use in contact with potable water, which makes it suitable for water-retaining structures as well as below-grade construction.
How we install it
Installation follows the manufacturer’s method statement. The concrete either side of the joint is mechanically prepared — ground back to a sound, clean, dust-free surface — and the tape zone is set out. Sikadur® epoxy adhesive (typically Sikadur®-31) is applied in a controlled thickness to both bonding strips, while the centre of the tape over the joint itself is deliberately left unbonded: this free central zone is what allows the tape to flex and absorb joint movement without being torn off its adhesive bed. On wide movement joints the tape is formed with a loop (Ω-profile) into the joint to increase its movement capacity. The tape is pressed into the fresh adhesive, rolled to expel air, and its edges are over-coated with a final stripe of epoxy to encapsulate them. Tape lengths are joined by hot-air welding, the same technique we use on our sheet-membrane work, so joints in the tape itself are homogeneous and testable. We install Combiflex as a stand-alone repair of leaking joints and cracks, and as an engineered complement to sheet and liquid membrane systems at movement joints, dissimilar-substrate transitions and difficult penetrations — anywhere a field membrane alone cannot safely carry the expected movement.
Material systems
Systems we install / are manufacturer-trained on — not partnerships.
Used for
- Movement / expansion joints
- Construction & connection joints
- Crack sealing & leak repair
- Water tanks & below-grade structures
- Detail / transition zones