Waterproofing

Surface Preparation

A high performance, pre-applied waterproofing membrane consists of a multi-layer composite material engineered to bond permanently and integrally with freshly poured concrete forming a unified component of the structure. This integral bond effectively prevents water ingress and lateral water migration between the membrane and the structure. PROOF HDPE 1200 consists of a high-density polyethylene (HDPE) film, a self-adhesive polymer layer, and a textured/coarse layer.

Horizontal Blinding

The substrate must be free of loose particles and sharp protrusions. Avoid curved or rounded substrates. The surface does not need to be dry, but standing water must be removed.

Vertical Sheet Piling

Use concrete, plywood, insulation or other approved facing to sheet piling to provide support for the membrane. When using board systems like timber lagging, ensure they are close-butted and maintain an alignment tolerance within 12mm.

Membrane Installation

Position the PROOF HDPE 1200 membrane so that the coarse, textured layer faces upward (toward the fresh concrete pour), while ensuring the smooth HDPE film side is in direct contact with the underlying substrate. Stagger end laps to prevent layer buildup. Align the following sheets to overlap the previous one by 75 mm along the marked selvedge. Ensure the underside of the next sheet is clean, dry, and free from contamination before overlapping. To achieve a continuous, smooth bond without creases, apply firm, consistent pressure using a heavy roller; any initial tack will quickly diminish.

Roll Ends and Cut Edges

Overlap all membrane roll ends and cut edges by a minimum of 75mm. Ensure the area is clean by wiping with a damp cloth if necessary and using a brush to remove all loose particles from the membrane's surface. Peel the release paper from the first side of the PROOF HDPE TAPE and affix its adhesive side to the substrate. Roll the tape firmly to ensure complete adhesion, avoiding any creases or voids. Peel off the remaining layer of release paper and attach another piece of the PROOF HDPE 1200 membrane to the exposed adhesive tape, rolling it firmly once more to ensure full adhesion. Brush off any floating particles from the surface of the PROOF HDPE 1200 membrane.

Concrete Pouring

Concrete must be poured within 40 days of applying the membrane and carefully vibrate it during pouring to avoid damaging the waterproofing materials.  

Formwork Removal

PROOF HDPE 1200 can be applied to removable formwork, such as slab perimeters, elevator and lift pits, etc. To ensure a secure surface bond, the formwork must stay in place until the poured concrete reaches adequate compressive strength.To ensure a secure surface bond, the formwork must stay in place until the poured concrete reaches adequate compressive strength.

PROOF HDPE 1200 is not recommended for conventional twin-sided wall forming systems. To achieve the minimum specified compressive strength, a structural concrete mix with an ultimate strength of 40N/mm² typically needs a cure time of approximately six days at an average ambient temperature of -4°C, or  two days at 21°C. Contact Colmef Technical Department for more details.

Corners

Form internal and external corners according to the provided diagrams, ensuring the membrane extends at least 100mm beyond the corner. Seal these sections with PROOF HDPE 1200 bonding tape, paying particular attention to covering and firmly rolling the tape over the corner apex. Fold and crease the membrane tightly against the substrate to maintain a flush profile and prevent hollow gaps.

Applications Recommendations