Installations

Temperature Requirements

• PREPRUFE®  300R and 160R Membranes can be applied at temperatures of -4°C or above. When installing PREPRUFE®  Membranes in cold or marginal weather conditions <13°C the use of PREPRUFE®  Tape LT is required at all laps and detailing. All surfaces to receive PREPRUFE®  Tape LT must be clean and dry before application. PREPRUFE®  300R and 160R Membrane release liner must be removed before application of PREPRUFE®  Tape LT. Release liner must be removed from PREPRUFE®  Tape LT immediately after application
• As an alternate, where temperatures are between -4°C and 15.5°C PREPRUFE®  300R (LT) and 160R (LT) Low Temperature Membranes can be used without taping of laps. Refer to the PREPRUFE®  300R (LT) and 160R (LT) Low Temperature Membranes data sheet for more information on cold weather application or contact your local GCP representative for support
• PREPRUFE®  300R & 160R Membranes are designed for in-service temperatures below 49°C

Substrate Preparation

• All surfaces – It is essential to create a sound and solid substrate to eliminate movement during the concrete pour. Substrates must be regular and smooth with no gaps or voids greater than 12 mm. Grout around all penetrations such as utility conduits, etc. for stability
• Horizontal – The substrate must be free of loose aggregate and sharp protrusions. Avoid curved or rounded substrates. When installing over earth or crushed stone, ensure substrate is well compacted to avoid displacement of substrate due to traffic or concrete pour. The surface does not need to be dry, but standing water must be removed
• Vertical – Use concrete, plywood, insulation or other approved facing to sheet piling to provide support to the Membrane. Board systems such as timber lagging must be close butted to provide support and not more than 12 mm out of alignment. For out of alignment from 12mm and up to 50mm HYDRODUCT®  200 or 220 or Rapid-Drain™ drainage sheet can be used to bridge voids, gaps and out of alignment prior to PREPRUFE®  Membrane installation

Membrane Application

PREPRUFE® 300R & 160R Membranes are supplied in rolls 1.2m wide, with a selvedge on one side to provide self-adhered laps for continuity between rolls. The rolls of PREPRUFE® Membrane and PREPRUFE® Tape are manufactured with a disposable plastic release liner must be removed before placing reinforcement and concrete. NOTE that the release liner must also be removed before application of any required Tapes and at all surfaces where a bond between layers is to be formed.

Horizontal substrates – PREPRUFE® 300R Membrane only. (PREPRUFE® 160R Membrane is for vertical use only)

PREPRUFE®  300R Membrane can be applied horizontally to smooth prepared concrete or well rolled and compacted earth or crushed stone substrate. Place the PREPRUFE®  300R Membrane with the clear plastic release liner and adhesive side facing the concrete pour and HDPE film side facing the substrate. End laps should be staggered to avoid a buildup of layers. Leave plastic release liner in position until overlap positioning is completed. When completed, remove release liner. When installing over carton forms, contact your local GCP representative.

Accurately position succeeding sheets to overlap the previous sheet 75 mm along the marked selvedge. Ensure the underside of the succeeding sheet is clean, dry and free from contamination before attempting to overlap. Peel back the plastic release liner from between the overlaps allowing the two overlapped layers to bond together. Ensure a continuous bond is achieved without creases and roll firmly with a heavy roller. Completely remove the plastic liner to expose the white protective coating. Any initial tack will quickly disappear.

Notes:

PREPRUFE® 300R Membrane can be returned up the inside face of slab formwork to attain a fully bonded system. After removal of formwork this allows a tie in with BITUTHENE® self-adhered Membrane or SILCOR® Waterproofing Membrane. For more information on SILCOR® Waterproofing  Membrane products contact your local GCP Representative.

Note that PREPRUFE® 300R & 160R Membranes are not recommended for use with conventional twin-sided formwork. (See PREPRUFE® Technical Letter TL-0013 (AP) Forming Systems For Use with PREPRUFE® Membranes)

Vertical substrates –

PREPRUFE®  300R &160R Membranes can be applied vertically to permanent formwork or adjoining structures. Concrete should then be cast directly against the adhesive side of the Membrane. The Membrane may be installed in any convenient length. The clear plastic release liner must be facing towards the concrete pour. Membrane must be shingle overlapped a minimum of 75mm.  All laps over cut edges must be taped using PREPRUFE®  Tape.

Vertically placed sheets can be held in place using fasteners appropriate to the substrate. Fastening should only be made through the selvedge overlap area using a small and low profile head fastener so that the Membrane lays flat and allows firmly rolled overlaps. Fasteners should be placed in the selvedge approximately 12.5mm from the edge of the Membrane. The adhesive selvedge of successive Membrane sheets must completely cover any fasteners by a minimum if 25mm. After rolling immediately remove the plastic release liner. When placing successive sheets insure the underside of each succeeding sheet is clean, dry and free from contamination before attempting to overlap. After placement roll the Membrane firmly to ensure a watertight seal.

Note that PREPRUFE® 300R & 160R Membranes are not recommended for use with conventional twin-sided formwork. (See PREPRUFE® Technical Letter TL-0013 (AP) Forming Systems For Use with PREPRUFE®  Membranes)

Roll ends and cut edges –

Overlap all roll ends and cut edges by a minimum 75 mm. Remove the release liner from the PREPRUFE®  membrane where the tape is to be applied at the lap and ensure the area is clean and free from contamination, wiping with a damp cloth if necessary. Allow surface to dry and apply PREPRUFE®  Tape LT* (or HC** in hot climates) centered over the lap edges and roll firmly. Immediately remove the plastic release liner from the PREPRUFE®  Tape.

*LT denotes Low Temperature (between -4˚C and +30˚C)
**HC denotes Hot Climates (>+10˚C)

Membrane Repair

Inspect the Membrane before installation of steel reinforcement, formwork and final placement of concrete. The Membrane can be easily cleaned with low pressure power washing if required. Repair damaged areas by wiping the area with a damp cloth to ensure the area is clean and free from dust, and other contaminants and allow the Membrane to dry. Repair small punctures and slices (12 mm or less) by applying PREPRUFE®  Tape centered over the damaged area. Repair punctures and holes larger than 12mm by applying a patch of PREPRUFE®  Membrane. Extend the patch 150 mm beyond the damaged area. Seal all edges of the patch with PREPRUFE®  Tape. Where exposed selvedge has lost adhesion or laps have not been sealed, ensure the area is clean and dry and cover with fresh PREPRUFE®  Tape. Any areas of damage or poor adhesion should be patched with PREPRUFE®  Tape. All PREPRUFE®  Tape must be rolled firmly and the tinted release liner removed.

Slices or relief cuts can be butted or overlapped and repaired by applying PREPRUFE®  Tape centered over the edge of the overlap or center of the butt joint. Where it is not possible to create a butt joint or overlap, repair with fresh Membrane and PREPRUFE®  Tape as detailed above.

Pouring of Concrete

Ensure the plastic release liner is removed from all areas of PREPRUFE®  300R & 160R Membrane and PREPRUFE®  Tape. The PREPRUFE®  membrane surface must be free of contaminants, dirt and debris and all standing water prior to placement of the concrete. Under most climatic conditions concrete should be poured within 56 days of membrane installation. Where ambient temperatures will exceed 38°C for more than a total of 7 days, concrete must be placed within 42 days of installation of the membrane. Following proper American Concrete Institute guidelines or respective national concrete standards, concrete must be placed carefully and consolidated properly to avoid damage to the membrane. Never use a sharp object to consolidate the concrete. Provide temporary protection from concrete splash over for areas of the PREPRUFE®  membrane that are adjacent to the concrete pour.

It is also important that concrete mix is designed, placed and compacted properly to ensure no segregation or excessive bleeding. This is critical for achieving desired bonding between concrete and PREPRUFE®  membranes, especially for membranes installed on vertical surfaces. Extra precautions are needed for concrete with slump value higher than 130mm as it is prone to have segregation and bleeding issues especially under lower ambient temperature.

Removal of Formwork

A minimum concrete compressive strength of 3000 psi (20 N/mm2) (minimum 3 days) is required prior to stripping formwork supporting PREPRUFE®  Membranes. Premature stripping may result in displacement of the Membrane and/or spalling of the concrete.

After removal of the formwork and prior to backfilling, all exposed PREPRUFE® Membrane must be protected from damage with an approved protective course.