PREPRUFE® 275 Membrane

Blindside waterproofing membrane for both cast-in-place concrete or shotcrete foundation walls and cast-in-place concrete slabs

Product Description

GCP Applied Technologies’ (“GCP”) PREPRUFE® 275 membrane is a composite sheet comprised of an HDPE film, an aggressive pressure sensitive adhesive and a weather resistant protective coating. Using patented Advanced Bond Technology™, PREPRUFE® 275 membrane provides a continuous seal to concrete or shotcrete resisting water ingress and migration between the membrane and the structure.

Product Advantages

  • Forms a continuous adhesive bond to concrete poured against it
  • Durable system designed specifically to withstand the force of shotcrete placement
  • Its unique continuous and integral bond to the structure is specifically designed to reduce lateral water migration between the membrane and the concrete or shotcrete
  • Designed with fully adhered adhesive to adhesive watertight ZipLap™ seams and easy to execute detailing
  • Provides a barrier to water, moisture and soil gases physically isolating the structure from the surrounding substrate
  • Release liner free, expedites installation and reduces construction site waste
  • Solar reflective surface results in reduced temperature gain
  • Simple and quick to install requiring no priming
  • Can be applied to permanent formwork - allows maximum use of confined sites
  • Installed membrane is unaffected by wet jobsite conditions – jobsite water will not cause premature activation
  • Waterproofing is not reliant on confining pressures or hydration
  • Installed membrane is unaffected by freeze/thaw or wet/dry cycles
  • Chemical resistance - protects structure from salt or sulphate attack effective in most types of soils and waters

Product Applications

PREPRUFE®275 membranes are designed for shotcrete walls as well as cast in place concrete with intermittent water and low or no hydrostatic condition. To provide long-term waterproofing performance in high-risk, hydrostatic and critical shotcrete conditions, PREPRUFE® SCS blindside waterproofing system is  recommended. Complete product information and a Product Data Sheet for PREPRUFE® SCS blindside waterproofing system can be found at 

System Components:


PREPRUFE® 275 waterproofing membrane is for horizontal use below concrete labs, or vertically against timber lagging or other soil retention systems. Intended for both cast-in-place and shotcrete applications.

Ancillary Components (refer to the most current Data Sheets for all system components available on

  • PREPRUFE® Tape LT — low temperature tape for covering cut edges, roll ends, penetrations, and detailing in cold weather
  • PREPRUFE® Tape HC — high temperature tape for covering cut edges, roll ends, penetrations, and detailing at elevated temperatures
  • PREPRUFE® CJ Tape LT — low temperature joint tape for construction joints, and detailing in cold weather
  • PREPRUFE® CJ Tape HC — high temperature joint tape for construction joints, and detailing in hot weather
  • BITUTHENE® Liquid Membrane — for sealing around penetrations, etc. 
  • ADCOR® — Waterstop for joints in concrete walls and floors
  • DE NEEF® INJECTO®  Tube — groutable waterstop for non-moving concrete construction joints and penetrations
  • PREPRUFE® Tieback Covers — preformed cover for soil retention wall tieback heads

Limitations of Use

  • Approved uses include only those specifically detailed in this Product Data Sheet and other current Product Data Sheets that can be found at
  • PREPRUFE® 275 membranes are not intended for any other use. Contact GCP Technical Services where any other use is anticipated or intended.
  • PREPRUFE® 275 membranes are designed for in-service temperatures below 120°F (49°C). For hydrostatic and critical waterproofing applications consider PREPRUFE® SCS blindside waterproofing system for shotcrete applications and PREPRUFE® Plus for cast-in-place concrete applications. See separate Product Data Sheet at

Safety and Handling

Users must read and understand the product label and Safety Data Sheets (SDS’s) for each system component before use. All users should acquaint themselves with this information prior to working with the material. Carefully read detailed precaution statements on the product labels and SDS’s before use. The  most current SDS’s can be obtained from our web site at or by contacting GCP toll free at 1-866-333-3SBM (3726).


  • Observe 1 year shelf life and use on a first in first out basis Store
  • In dry conditions between 40°F (4.5°C) -90°F (32°C)
  • Store off ground under tarps or otherwise protected from rain and ground moisture
  • See TL-0030 — Shelf Life/Storage and Handling of GCP Applied Technologies Waterproofing and Air Barrier Products Technical Letter


Technical Support, Details and Technical Letters

The most up to date detail drawings and technical letters are available at For complete application instructions, please refer to the current GCP Applied Technologies Contractor Handbook and Literature on ( Documents in hardcopy as well as information found on websites other than may be out of date or in error. Before using this product it is important that information be confirmed by accessing and reviewing the most recent product information, including without limitation Product Data Sheets and Contractor Manuals, Technical Bulletins, Detail Drawings, and detailing recommendations. Please review all materials prior to installation of  PREPRUFE® 275 membrane.

Support is also available by full-time technically trained GCP Applied Technologies field sales representatives and technical service personnel, backed by a central research and development technical services staff. For technical assistance with detailing and problem solving please call toll-free at (866) 333-3SBM (3726).

Temperature Requirements

PREPRUFE® 275 membranes can be applied at temperatures of 25°F (- 4°C) or above. When installing
PREPRUFE® 275 membranes in cold or marginal weather conditions <40°F (<4°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 and the release liner must be removed immediately after application.
PREPRUFE® 275 membranes are designed for in-service temperatures below 120°F (49°C)

Substrate Preparation

All surfaces — It is essential to create a sound and solid substrate to eliminate movement during the concrete or shotcrete placement. Substrates must be regular and smooth, with no gaps or voids greater than 0.5 in. (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. 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 0.5 in. (12mm) out of alignment.

Membrane Application

PREPRUFE® 275 membranes can be applied in horizontal applications to smooth prepared concrete, or well rolled and compacted earth or crushed stone substrate. Kick out or roll out the membrane, with the HDPE film side to the substrate with the green ZipStripTM facing towards the concrete pour. End laps should be staggered to avoid a buildup of layers. Leave the green and blue ZipStripsTM on the membrane until the overlap procedure is completed. When completed, remove the release liner. Contact your local GCP representative for further details when installing over carton forms. 

Accurately position succeeding sheets to overlap the previous sheet 3 in. (75 mm) along the marked selvedge with the blue ZipStripTM on top of the green ZipStripTM. Ensure the underside of the succeeding sheet is clean, dry and free from contamination before attempting to overlap. Peel back and remove both the green and blue ZipStripsTM in the overlap area to achieve an adhesive-to-adhesive bond at the overlap. Ensure a continuous bond is achieved without creases, and roll firmly with a heavy roller. 

PREPRUFE® 275 Membrane can be returned up the inside face of slab formwork. To attain a fully bonded system and to allow a tie in with BITUTHENE® self-adhered membrane or PROCOR® fluid-applied membrane to all vertical structural surfaces after removal of formwork. (See PREPRUFE® Technical Letter #TL-0013 Forming Systems for Use with PREPRUFE® Membranes.) Roll ends and cut edges – Overlap all roll ends and cut edges by a minimum 3 in. (75 mm) 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 tinted plastic release liner from the tape. 

PREPRUFE® 275 is intended for low hydrostatic pressure conditions. For critical projects, GCP recommends the use of PREPRUFE® Plus (for cast-in-place concrete applications) and PREPRUFE® SCS (for shotcrete applications) for long-term waterproofing performance. See separate data sheets for more details.

Membrane Repair

Inspect the membrane before installation of reinforcement steel, formwork, and final placement of  shotcrete. The membrane can be easily cleaned by low pressure power washing if required. Repair damage 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 (0.5 in. (12 mm) or less by applying PREPRUFE® Tape centered over the damaged area. Repair punctures and holes larger than 0.5 in. (12mm) by applying a patch of PREPRUFE® membrane. Extend the patch 6 in. (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 damaged adhesive should be covered 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.

Reinforcing Steel Anchors

Only compatible rebar supports such as concrete dobies shall be placed against the PREPRUFE® 275 membrane. The steel should be tied to the shoring system using GCP approved anchors only. Contact your local GCP representative for additional information.

Shotcrete Placement

Important: Prior to concrete or shotcrete placement, ensure that the zip strip liner and any plastic release liner is completely removed from all areas of PREPRUFE® 275 membrane and PREPRUFE® Tape.
Concrete or shotcrete should be placed within 56 days (42 days in hot climates) of application of the membrane. Shotcrete must be placed in accordance with ACI 506.2. Never use a sharp object to consolidate the concrete or shotcrete.

It is highly recommended that the PREPRUFE® 275 membrane system be included in preconstruction test panels successfully meeting the project specifications. The test panel needs a mean core grade less than or equal to 2.5 as described and defined in ACI 506.2 shall be allowed to place shotcrete against the PREPRUFE® 275 membrane. Individual shotcrete cores greater than 3 are unacceptable.


Thickness 0.038 in. (0.95 mm)
Roll size 3 ft 10 in. x 120 ft (1.17 m x 36.6 m)1
Roll weight 102 lbs (46 kg)
Minimum side/end laps 3 in. (75 mm)

Note#1 Individual roll length may vary +/-1%

Physical Properties (PREPRUFE® 275 MEMBRANE)

Color white  
Thickness 0.038 in. (0.95 mm) ASTM D3767
Lateral Water Migration Resistance Pass at 231 ft (71 m) of hydrostatic head pressure ASTM D53851
Low Temperature Flexibility Unaffected at -20°F (-29°C) ASTM D1970
Resistance to hydrostatic head 231 ft (71 m) ASTM D53852
Elongation 300% ASTM D4123
Tensile strength, film 4000 psi (27.6 Mpa) ASTM D412
Crack cycling at -9.4°F (-23°C), 100 cycles Unaffected, Pass ASTM C8364
Puncture resistance 135 lbs (600 N) ASTM E154
Peel adhesion to concrete 4 lbs/in. (700 N/m) ASTM D9035
Lap peel adhesion at 72°F (22°C) 7 lbs/in. (1225 N/m) ASTM D18766
Lap peel adhesion at 40°F (4°C) 7 lbs/in. (1225 N/m) ASTM D18766
Permeance to water vapor transmission 0.01 perms (0.6 ng/(Pa x s x m2)) ASTM E96, method B
  1. Lateral water migration resistance is tested by casting concrete against membrane with a hole and subjecting the membrane to hydrostatic head pressure with water. The test measures the resistance of lateral water migration between the concrete and the membrane.
  2. Hydrostatic head tests of PREPRUFE ® Membranes are performed by casting concrete against the membrane with a lap. Before the concrete cures, a 0.125 in. (3 mm) spacer is inserted perpendicular to membrane to create a gap. The cured block is placed in a chamber where water is introduced to the membrane surface up to the head indicated.
  3. Elongation of membrane is run at a rate of 2 in. (50 mm) per minute at 72°F (22°C).
  4. Concrete is cast against the PREPRUFE ® membrane and allowed to cure (7-days minimum).
  5. Concrete is cast against the PREPRUFE ® membrane and allowed to cure (7-days minimum). Peel adhesion of membrane to concrete is measured at a rate of 2 in. (50 mm) per minute at 72°F (22°C).
  6. The test is conducted 15 minutes after the lap is formed at evaluation temperature with rate of 2 in. (50 mm) per minute. | North America Customer Service: 1 877-4AD-MIX1 (1 877-423-6491)

We hope the information here will be helpful. It is based on data and knowledge considered to be true and accurate, and is offered for consideration, investigation and verification by the user, but we do not warrant the results to be obtained. Please read all statements, recommendations, and suggestions in conjunction with our conditions of sale, which apply to all goods supplied by us. No statement, recommendation, or suggestion is intended for any use that would infringe any patent, copyright, or other third party right.

ADCOR, PREPRUFE, PROCOR, and BITUTHENE are trademarks, which may be registered in the United States and/or other countries, of GCP Applied Technologies Inc. This trademark list has been compiled using available published information as of the publication date and may not accurately reflect current trademark ownership or status.

© Copyright 2021 GCP Applied Technologies Inc. All rights reserved.

GCP Applied Technologies Inc., 62 Whittemore Avenue, Cambridge, MA 02140 USA.

In Canada, GCP Canada, Inc., 294 Clements Road, West, Ajax, Ontario, Canada L1S 3C6

This document is only current as of the last updated date stated below and is valid only for use in the United States. It is important that you always refer to the currently available information at the URL below to provide the most current product information at the time of use. Additional literature such as Contractor Manuals, Technical Bulletins, Detail Drawings and detailing recommendations and other relevant documents are also available on Information found on other websites must not be relied upon, as they may not be up-to-date or applicable to the conditions in your location and we do not accept any responsibility for their content. If there are any conflicts or if you need more information, please contact GCP Customer Service.

Last Updated: 2021-02-26