COREFLEX® Waterproofing Membrane

The Gold Standard of Construction Waterproofing

COREFLEX waterproofing membrane sets the standard for waterproofing, with over 50 years of unmatched strength, durability, ease of installation, and performance.


It’s that good.


Superior Waterproofing Technology

For cast-in-place concrete, masonry block foundation walls, or soldier pile and lagging, the COREFLEX waterproofing system provides waterproofing protection for any structural below-grade concrete surface, such as:

  • Plaza Decks
  • Split-Slab Deck Construction
  • Foundation Walls
  • Earth-Covered Structures
  • Property Line Construction
  • Under Slab
  • Tunnels
  • Green roofs

Whether a structure is under continuous or intermittent hydrostatic pressure, COREFLEX is your most reliable barrier against water. Combining two kinds of barriers—passive and active—COREFLEX substantially reduces the possibility for leaks, with its traditional passive barrier blocking water while the active volcanic bentonite component of its core absorbs up to 15 times its volume in water, expanding to seal cracks using the very pressure of the water itself to fill and block any gaps.


Easy Installation Saves You Money

Easy to install even in cold weather, COREFLEX is also easy on your budget, saving you money in time and installation, especially in remedial waterproofing projects. With no additional preparation, simply lay it over any existing surface requiring waterproofing—even an already-treated surface, no primers or adhesives required. Flexible COREFLEX not only conforms easily, but its fibrous outer layer bonds to nearly any concrete surface—it can even be continued under a floor slab and up onto a horizontal deck for continuous, uniform waterproofing.


Durable and Resistant to Fire and Chemicals

COREFLEX is extremely durable. Self-sealing and self-seaming—the only composite barrier with this ability—there’s no worries about the inevitable cuts and punctures that always occur on construction sites. What’s more, COREFLEX is fire retardant, with component materials that self-extinguish to prevent the spread of flames when most other water barrier products burn and fall apart. And COREFLEX resists chemicals and harsh contaminants such as diesel, kerosene, or jet fuel, providing protection that qualifies it as a Class “A” vapor retarder and certified methane barrier.


How It Does It

COREFLEX features a 1.5 mm (60 mil) nominal thermoplastic membrane with welded seams that provide a watertight barrier layer. It’s reinforced with a 5.0 oz weft inserted knit polyester fabric integrally bonded to an Active Polymer Core (APC). The fabric is produced with DuPont’s Elvaloy-KEE® (Keytone Ethylene Ester), a solid phase high molecular weight ethylene interpolymer that also provides superior chemical resistance.


Unlike traditional liquid PVC plasticizers, the Elvaloy-KEE doesn’t experience phase separation and migrate out—in other words, the membrane properties are maintained for long-term performance, with the Active Polymer Core layer integrally bonded to the Elvaloy-KEE thermoplastic membrane. Employing the mineral bentonite, the core is designed to activate with water and swell to form a positive seal. The APC layer reacts at the breach of any puncture or defect to self-seal and prevent water ingress—COREFLEX is the only welded thermoplastic membrane composite with this reactive, self-sealing feature.


CETCO - Pioneer and Leader in Waterproofing

CETCO is the leader and pioneer in cutting-edge waterproofing membranes. Around the globe, our innovative teams of clay mineralogists, chemists, and polymer scientists transform ordinary minerals into extraordinary technology to solve day-to-day problems worldwide.





    Adhesive SB-100

    Adhesive for securing COREFLASH membranes to various substrates, including cured concrete, wood, metal and cementitious boards.
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    Hydrophilic polyurethane caulk used for detail work including pipe penetrations.
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    Foundation drainage composite consisting of a molded profile core and a filter fabric. System includes drainage and base drain collection.
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    A multi-purpose UV stable single component polyether moisture cure sealant/adhesive. Primary applications are grade termination sealant, membrane lap sealant and waterstop adhesive.
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    Preformed non-reinforced thermoplastic flashings, designed to provide a welded thermoplastic cover over tie-back heads on property line shoring walls; three preformed sizes available. CORECAP(S) used in conjunction with same size rigid TB-Boot.
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    A 24 ga. (0.61 mm) stainless steel sheet laminated on one side with thermoplastic polymeric coating for flashing applications.
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    A nominal 100 mm (4”) round x 1.5 mm (60 mil) non-reinforced thermoplastic disc. COREDISCS are used for T-joint patches and to repair small punctures in the PVC membrane.
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    1.5 mm (60 mil) thick UV stable non-reinforced extruded white thermoplastic membrane used for detail and flashing applications including curbs, walls, field wraps and patches.
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    1.5 mm (60 mil) thick UV stable non-reinforced extruded white thermoplastic membrane used for detail and flashing applications including curbs, walls, field wraps and patches.
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    1.5 mm (60 mil) thick UV stable reinforced thermoplastic membrane (white top coat and black bottom coat) used for flashing applications exposed to direct UV and/or weathering conditions including curbs, walls, field wraps and patches.
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    Active Polymer Core (APC) polymer impregnated geotextile for transition details, corners, butt-joints and protection from rough edges and surfaces. 
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    Used with COREFLEX XP, CORETEX XP is a polymer impregnated geotextile featuring XP technology for transition details, corners, butt-joints and protection from rough edges and surfaces.

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    80 mm (3.25 inch) diameter nominal metal plate with thermoplastic coating for attachment of COREFLEX membrane to shoring with induction welding machine. 

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    Molded non-reinforced thermoplastic flashings, specially designed for round penetrations 50 mm (2”) or less in diameter.

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    Pre-fabricated factory welded thermoplastic pipe penetration sleeve with open cut side for simply installation around 75 mm (3 inches) to 100 mm (4 inches) pipe penetrations; comprised of a non-reinforced 60 mil membrane stack and a 60 mil reinforced membrane base flange. 

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    SEAL-X® XP
    A trowel-grade detailing mastic designed for a variety of surface preparation and detailing work. It swells upon contact with water to form a watertight barrier, even in high-saline water conditions.

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    Specially designed anchors that allow for rebar to be tied into and supported without creating membrane penetrations.

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    Universal Corner

    A molded non-reinforced thermoplastic flashings used to seal inside and outside corner details. Universal Corners come as one piece and are trimmed to fit the appropriate corner condition.

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    Hydrophilic, swelling concrete joint waterstop used around penetrations and applicable concrete joints. WATER-STOP-RX swells upon hydration to form a positive seal in concrete cold pour joints.

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    Featuring XP technology, WATERSTOP-XP is proven effective in a wide range of environments including high-saline conditions. Effective for both horizontal and vertical joints, it expands upon contact with water to form a positive seal to stop water ingress through cast-in-place concrete construction joints and around pipe penetrations.

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    Architectural Specs
    In the News
    Waterproofing Techniques for Bored Tunnels - Waterproof Magazine, October 2012
    Traditional Roofing vs. New Alternatives - Waterproof Magazine, October 2008
    Technical References
    Technical Data Sheets