What is PREFLEX 3000 used for?

PREFLEX 3000 is a pre-applied HDPE sheet membrane for below-slab and blindside waterproofing - laid before the concrete pour, bonds fully to the poured concrete via composite layers. Used for foundations, basements, and lift shafts where access for post-applied membrane is impossible.

How does pre-applied bonding work?

PREFLEX 3000 has a composite layer system that mechanically and chemically bonds to the freshly poured concrete - creating a permanent integral seal that prevents lateral water migration between membrane and structure. No primers or protection layers required.

Lay the membrane HDPE-side-down against the substrate (blindside) or formwork. Overlap edges using the self-adhesive selvedge for sealed laps. Pour the concrete directly onto the membrane - the bond develops as concrete cures.

20 m² per roll at 1.5mm thickness (with sand layer). Designed for 1m wide x 20m long format that handles full-area below-slab installations efficiently.

What environmental conditions does it handle?

PREFLEX 3000 flexes to -30°C without cracking, achieves over 500% elongation (tested 590-645%), and resists groundwater salts, hydrocarbons, and sulfates - the most aggressive below-grade chemistry.

Forspec Actflex 300 Solvent Free Two Part Reactive Coating Membrane for waterproofing, concrete protection, and crack-bridging applications, providing a durable seamless barrier for internal and external surfaces

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PREFLEX 3000 1m x 20m Pre-Applied HDPE Sheet Membrane

Name: PREFLEX 3000 1m x 20m Pre-Applied HDPE Sheet Membrane
Brand: Forspec Protective Coatings
SKU: PPRF398
Price: 880.00 AUD
Availability: InStock

$880.00

or 4 interest-free payments with

Pre-applied HDPE sheet that bonds to the slab as it is poured. No primer, no heat, no protection layer.

PREFLEX 3000 is a fully bonded HDPE membrane for below-ground work where the waterproofing goes in before the concrete. Wet concrete cast against its sand-finished face locks onto it, so water cannot track sideways between membrane and structure. 1 m x 20 m roll, 1.7 mm thick.

Where to use it

Basement slabs and below-ground floor structures
Blindside and back-of-wall work on reinforced concrete retaining walls
Lift pits and plant pits
Cut-and-cover tunnels and subway structures
Pile caps and capping beams

Why waterproofers buy it

Class III to AS 4654.1 on ISO/IEC 17025 accredited lab testing. 1273% elongation
Bond holds through ground settlement and structural movement
Passive. No water activation, bentonite or confining pressure. Wet sites do not set it off
No primer, no torching, no power tools, no separate protection layer. Takes site traffic straight after laying
Resists groundwater, salts, chlorides, sulphates and hydrocarbons
Factory self-adhesive selvedge for watertight side laps

Coverage

20 m² gross per roll. Net coverage is gross less side and end laps and cutting waste, worked out per project from the approved detail. Allow a 300 to 400 mm floor upturn at walls.

Not for

Post-applied use, permanently exposed work (pour within 56 days, or 42 days in heat over 38°C for more than seven days straight), screws or nails through sheets or laps, active water (stop it with ACTFLEX HYDROPLUG first), solvents on the sand face, or bridging movement joints without a project detail.

Fully bonded to poured concrete, eliminating lateral water migration

No primers, no torching, no power tools and no separate protection layer

Self-protecting - accepts site traffic immediately after installation

Quantity: 1

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PREFLEX 3000 1m x 20m Pre-Applied HDPE Sheet Membrane

The Waterproofing Shop

Pickup available, usually ready in 24 hours

22/872 Canterbury Road
Roselands NSW 2196
Australia

+61280213517

Product Details

This integral bond is specifically designed to provide a robust barrier against water, moisture, and gas, preventing both ingress and lateral migration. Selvedge overlaps deliver superior performance in harsh conditions without the need for specialized equipment, heat, or power.

ADVANTAGES:

Acts as a vapor barrier, forming a unique integral bond to the poured concrete and remaining in place if any ground settlement of substrate occurs.
Simple and reliable application with no primers or protection required.Combines toughness with flexibility for detailing around edges.
Resistant to groundwater and protects concrete from ground salts, chlorides, sulfates, and hydrocarbons in contaminated areas.
Unaffected by wet job site conditions, ensuring it doesn't activate prematurely.
Inherently waterproof as supplied, this passive, non-reactive waterproofing system does not require water activation.
Waterproofing is not dependent on confining pressures or hydration.

For more information about this product, see the Technical Data Sheet.

How to Use

Roll out by hand with the sand-finished face toward the future concrete, close laps on the factory self-adhesive selvedge and concealed NS Tape, and pressure roll every lap from the centre outwardConfirm and formally accept the substrate before any membrane is released; the waterproofing supervisor signs the substrate record before the first roll is opened
Confirm blinding concrete is minimum 20 MPa, sound and free of laitance, fins, slurry, loose particles, tie-wire ends, sharp edges, oil, curing compound and standing water
Break out unsound concrete to a sound edge and fill honeycombing, voids and deep irregularities with an approved repair mortar, cured, without feather edges
Form dry wall-floor junctions as a smooth 45 degree FORBUILD 100 mortar cove primed with ACTFLEX 300 Primer, and protect it at least 48 hours before the membrane is installed
Stop active water with ACTFLEX HYDROPLUG worked into a sound chase of not less than 20 x 20 mm and set before any coating or tape is applied
Rectify structural and live cracks with PROBOND 1100, CRACK PRO 1200PS or CRACKLOCK E400L before waterproofing proceeds
Do not prime the membrane or the substrate beneath it; PREFLEX 3000 requires no primer
Set out from the approved grid, not from an irregular excavation edge, and plan the first sheet so the selvedge receives the next
Lay without dragging or stretching, presenting the sand-finished face toward the future concrete with the HDPE backing against the substrate or support
Close side laps on the factory self-adhesive selvedge and end laps over concealed PREFLEX 3000 NS Tape, and pressure roll every lap from the centre outward
Turn the floor membrane 300-400 mm up adjoining walls as a continuous upturn, kept visible for the later wall return
Remove wrinkles, bridging, air pockets, sharp inclusions and trapped liner; never bury a wrinkle beneath the next sheet
Complete the floor field, perimeter upturn, grade-beam returns, pile-cap transitions and nearby penetrations and have them accepted before starting wall sheets
Bring the wall sheet down over the floor upturn and turn it horizontally as an L-shaped return over the floor field, bonded on concealed NS Tape and fully rolled
Finish internal base corners with a circular S Tape patch at the three-plane corner; vertical figure-eight patches are not permitted
Repair damage 12 mm or smaller with PREFLEX 3000 S Tape centred over the damage; repair damage greater than 12 mm with a patch extending at least 150 mm beyond it in every direction, bonded on concealed NS Tape and sealed at the perimeter with S Tape
Remove all release liners, clean the membrane and repair every defect before the pour, with all sand-finished faces exposed and bondable and no NS Tape exposed
Obtain the waterproofing supervisor's pre-pour checklist sign-off; no concrete placement is permitted before sign-off
Place concrete within 56 days of membrane installation and strip formwork only after the concrete reaches minimum 20 MPa compressive strength

Technical Specifications

Membrane Classification: Class III (high extensibility), AS 4654.1*
Construction: HDPE carrier film, polymer layer and thermo-reactive sand-finished bonding surface
Finished Thickness: 1.7 mm (1.5 mm HDPE base + 0.2 mm sand finish)*
Tensile Strength: 12.83 MPa (AS 1145.3)*
Elongation at Break: 1273% (AS 1145.3)*
Cyclic Movement: Pass, no failures (AS 4654.1 App. B)*
Durability, Water Immersion: Pass, 1249% and 11.40 MPa retained (AS 4654.1 App. A)*
Durability, Detergent Immersion: Pass, 1275% and 12.61 MPa retained (AS 4654.1 App. A)*
Durability, Heat Ageing: Pass, 1165% and 12.23 MPa retained (AS 4654.1 App. A)*
Dimensional Stability: No change (ASTM D6207)*
Abrasion Resistance, Non-Trafficable: 0.047 mm (AS 1580.403.2)*
Abrasion Resistance, Trafficable: 0.071 mm (AS 1580.403.2)*
Field Seam Strength: 288.73 N/25 mm (AMTM 005)*
Water Vapour Transmission: 0.10 g/m2/24 h (ASTM E96 / AMTM 004)*
Resistance to Puncture: 500 mm (BS EN 12691)*
Water Impermeability: No visible penetration, 0.04 g mass gain (AS ISO 13007.5 App. A.7)*
Roll Size, Standard: 1 m x 20 m (20 m2 gross)
Roll Size, Wide: 2 m x 20 m (40 m2 gross)
Priming: None required, PREFLEX 3000 requires no primer
Floor Upturn at Walls: 300-400 mm
Concrete Pour Window: Within 56 days of membrane installation
Concrete Pour Window, Hot Conditions: Within 42 days where temperature exceeds 38C for more than seven consecutive days
Formwork Stripping: Concrete to reach minimum 20 MPa compressive strength
Storage: 10-25C and below 50% relative humidity
Safety Data Sheet: Chemwatch 5689-17
* Typical R&D characteristic values derived from ISO/IEC 17025 accredited laboratory testing to AS 4654.1; the test report is being reissued under the correct product name

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System Build-Up Guide

Correct application makes all the difference.

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Pool System Build-Up

1 Concrete Substrate
2 Crack Repair (if required)
3 ACTFLEX FLEXPLUS
4 ACTFLEX HYDROPLUG
5 ACTFLEX AT MESH
6 ACTFLEX 988 CWP (2 Coats)
7 Tile Adhesive
8 Pool Finish

Retaining Wall System Build-Up

1 Concrete Substrate
2 Crack Repair (if required)
3 ACTFLEX MS PRO
4 ACTFLEX AT MESH
5 ACTFLEX 988 CWP (2 Coats)
6 Protection Board (Optional)
7 Drainage System
8 Backfill

Tank System Build-Up

1 Concrete Substrate
2 Crack Repair (if required)
3 ACTFLEX FLEXPLUS
4 ACTFLEX AT MESH
5 ACTFLEX 988 WMP (2 Coats)
6 Protective Coating (Optional)
7 Water

Technical overview

PREFLEX 3000 is a pre-applied, fully bonded HDPE waterproofing membrane for below-ground structures where the waterproofing must be installed before the concrete is poured and where access to the outside face will never again be possible. It is a multi-layer composite of a high-density polyethylene carrier film, a polymer layer and a proprietary thermo-reactive bonding surface, finished to 1.7 mm. Wet concrete cast directly against it forms an integral mechanical and adhesive bond, so water reaching any single point cannot migrate laterally between membrane and concrete. It is Class III to AS 4654.1-2012 on ISO/IEC 17025 accredited laboratory testing, but the values are published as typical characteristic values pending reissue of the test report under the correct product name. No Australian Standard currently governs pre-applied below-ground membranes.

Key applications

Basement slabs and below-ground floor structures
Blindside and back-of-wall applications to reinforced concrete retaining walls
Lift pits and plant pits
Cut-and-cover tunnels and subway structures
Pile caps and capping beams, detailed with the FORSPEC system components
Below-ground structures where the external face is permanently inaccessible after construction

Surface suitability

Compacted fill or crushed dust (engineered and stable, free of hollows, ridges, sharp stones and protrusions, with designed falls)
Blinding concrete (minimum 20 MPa, sound, dimensionally stable and sufficiently smooth to provide continuous sheet support)
Structural concrete and permanent formwork (sound and continuous, honeycombing, voids and deep irregularities filled with an approved repair mortar and cured)
Blindside support systems (continuous, sound and smooth enough for full sheet support and pressure rolling)

Pre-applied only - concrete must be cast directly against the bonding surface; this is not a post-applied membrane. Not for permanently exposed use - protect from prolonged UV and pour within 56 days, or within 42 days where temperature exceeds 38C for more than seven consecutive days. Do not trap standing water, mud or frost beneath laps; adhesive zones must be clean and dry before closing. Do not install over an unacceptable substrate or unresolved water ingress - stop active water with ACTFLEX HYDROPLUG first. No screws, nails or washers through field sheets or any adhesive lap zone. Temporary restraint is permitted only in the approved top or termination zone, and must be sealed before the pour. PREFLEX 3000 NS Tape must never remain exposed to fresh concrete - it is a concealed tape only. Do not use solvents, aggressive detergents, or any method that polishes or strips the sand-finished face. Do not rigidly bridge a designed movement joint or a moving penetration - obtain a project-specific detail. Approved project drawings and specifications take precedence.

Technical Specifications

Membrane Classification	Class III (high extensibility), AS 4654.1*
Construction	HDPE carrier film, polymer layer and thermo-reactive sand-finished bonding surface
Finished Thickness	1.7 mm (1.5 mm HDPE base + 0.2 mm sand finish)*
Tensile Strength	12.83 MPa (AS 1145.3)*
Elongation at Break	1273% (AS 1145.3)*
Cyclic Movement	Pass, no failures (AS 4654.1 App. B)*
Durability, Water Immersion	Pass, 1249% and 11.40 MPa retained (AS 4654.1 App. A)*
Durability, Detergent Immersion	Pass, 1275% and 12.61 MPa retained (AS 4654.1 App. A)*
Durability, Heat Ageing	Pass, 1165% and 12.23 MPa retained (AS 4654.1 App. A)*
Dimensional Stability	No change (ASTM D6207)*
Abrasion Resistance, Non-Trafficable	0.047 mm (AS 1580.403.2)*
Abrasion Resistance, Trafficable	0.071 mm (AS 1580.403.2)*
Field Seam Strength	288.73 N/25 mm (AMTM 005)*
Water Vapour Transmission	0.10 g/m2/24 h (ASTM E96 / AMTM 004)*
Resistance to Puncture	500 mm (BS EN 12691)*
Water Impermeability	No visible penetration, 0.04 g mass gain (AS ISO 13007.5 App. A.7)*
Roll Size, Standard	1 m x 20 m (20 m2 gross)
Roll Size, Wide	2 m x 20 m (40 m2 gross)
Priming	None required, PREFLEX 3000 requires no primer
Floor Upturn at Walls	300-400 mm
Concrete Pour Window	Within 56 days of membrane installation
Concrete Pour Window, Hot Conditions	Within 42 days where temperature exceeds 38C for more than seven consecutive days
Formwork Stripping	Concrete to reach minimum 20 MPa compressive strength
Storage	10-25C and below 50% relative humidity
Safety Data Sheet	Chemwatch 5689-17
* Typical R&D characteristic values derived from ISO/IEC 17025 accredited laboratory testing to AS 4654.1; the test report is being reissued under the correct product name

Real Projects. Real Results.

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Frequently asked questions

View all FAQs

What is PREFLEX 3000 used for?

Compatibility
PREFLEX 3000 is a pre-applied HDPE sheet membrane for below-slab and blindside waterproofing - laid before the concrete pour, bonds fully to the poured concrete via composite layers. Used for foundations, basements, and lift shafts where access for post-applied membrane is impossible.
How does pre-applied bonding work?

Performance
PREFLEX 3000 has a composite layer system that mechanically and chemically bonds to the freshly poured concrete - creating a permanent integral seal that prevents lateral water migration between membrane and structure. No primers or protection layers required.
How is it installed?

Installation
Lay the membrane HDPE-side-down against the substrate (blindside) or formwork. Overlap edges using the self-adhesive selvedge for sealed laps. Pour the concrete directly onto the membrane - the bond develops as concrete cures.
Coverage per roll?

Compatibility
20 m² per roll at 1.5mm thickness (with sand layer). Designed for 1m wide x 20m long format that handles full-area below-slab installations efficiently.
What environmental conditions does it handle?

Performance
PREFLEX 3000 flexes to -30°C without cracking, achieves over 500% elongation (tested 590-645%), and resists groundwater salts, hydrocarbons, and sulfates - the most aggressive below-grade chemistry.

PREFLEX 3000 1m x 20m Pre-Applied HDPE Sheet Membrane

Frequently bought together

Pool System Build-Up

Retaining Wall System Build-Up

Tank System Build-Up

Technical overview

Key applications

Surface suitability

Technical Specifications

Pool Renovation

Below Ground Retaining Wall

Concrete Water Tank

Commercial Podium

Swimming Pool Construction

The Waterproofing Shop?

Frequently asked questions

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