What substrates can WPM 300 be applied to?

WPM 300 is a moisture-tolerant epoxy primer designed for concrete with high residual moisture (up to 95% RH). It bonds to green concrete, damp slabs, and surfaces with rising damp.

What problem does WPM 300 solve?

WPM 300 acts as a moisture vapour barrier on concrete slabs prior to installing moisture-sensitive flooring, tile adhesives, or levelling compounds. It blocks rising damp and accelerates project timelines.

How is WPM 300 applied?

Apply by roller or brush in two coats at 90 degrees to each other. Broadcast clean kiln-dried sand into the wet second coat to provide a mechanical key for subsequent layers.

Is WPM 300 safe to use indoors?

Yes. WPM 300 is solvent-free, low-VOC, and low-odour, making it safe for use in occupied buildings and confined spaces.

How thick should the membrane be?

A two-coat application typically delivers 300-400 microns dry film thickness, which is the minimum required to act as an effective moisture vapour barrier.

ARDEX WPM 300 Hydrepoxy water-based epoxy waterproofing membrane

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Ardex WPM 300

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Water-based epoxy moisture barrier. Two-part kit, withstands 250kPa hydrostatic pressure, potable water compliant.

ARDEX WPM 300 (HydrEpoxy) is a two-component water-based epoxy primer and barrier coating. It bonds to damp surfaces and green concrete, withstands 250kPa hydrostatic pressure (a 25 metre head of water), and is potable drinking water compliant under AS4020 and SS375. Mix 1:1 by volume, apply at 3.0 m²/L per coat, recoat after 4 hours.

Where to use it

Moisture barrier over green, damp or efflorescence-producing concrete before levelling compounds, carpet and tile adhesives
Tanking applications, including potable water containment
Nominated primer where substrate moisture exceeds 80% RH or 15 g/m²/24hrs
Hydrostatic pressure resistant waterproofing to prevent water seepage through walls and floors
Primer for ARDEX Liquid Applied Waterproofing Membranes

Why waterproofers buy it

Bonds to damp surfaces and green concrete
Withstands 250kPa hydrostatic pressure, equivalent to 25 metres head of water
Potable drinking water compliant under AS4020 and SS375
Water based, semi-gloss finish
Low water vapour transmission as barrier or seal coating
Two-part epoxy for long-term durability

Coverage

20L kit: apply at 3.0 m²/L per coat, two coats to 1.5 m²/L in total for moisture barrier applications (approx. 30 m² per 20L kit). Recoat 4 hours at 25°C and 50% RH. Single coat where used as a primer for ARDEX liquid applied membranes.

Not for

Not a trafficable coating. Do not apply at ambient temperature below 10°C or above 35°C. Do not apply above 85% relative humidity. Tiling can commence after 24 hours but must not exceed 5 days. Ventilation must be provided during curing.

All times at 25°C and 50% RH.

Bonds to damp surfaces and green concrete

Withstands 250kPa hydrostatic pressure, a 25 metre head of water

Potable drinking water compliant - AS4020 and SS375

Size: 20 Ltr Grey

20 Ltr Grey$463.704 Ltr Grey$147.9020 Ltr Black$596.90

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Ardex WPM 300

20 Ltr Grey

The Waterproofing Shop

Pickup available, usually ready in 24 hours

22/872 Canterbury Road
Roselands NSW 2196
Australia

+61280213517

Product Details

Key Benefits of ARDEX WPM 300 (HydrEpoxy):

1. Superior Protection: This water-based epoxy primer forms a robust barrier that protects substrates from moisture, chemicals, and other environmental factors, ensuring long-lasting durability.
2. Easy Application: With its user-friendly composition, ARDEX WPM 300 (HydrEpoxy) can be effortlessly applied, allowing for efficient and time-saving installation.
3. Versatile Usage: This multi-purpose coating can be used in diverse applications, including industrial floors, basements, garages, commercial kitchens, and more, making it a versatile solution for various surfaces.

How to Use

Spread on floors with a squeegee or stiff nylon broom and finish with a medium to long nap roller; apply to walls by roller, at 3.0 m2/L per coatRemove all dirt, dust, curing compounds, oils, grease, surface sealers and other contaminants by mechanical methods and vacuum cleaning
Leave the surface sound, clean and free from sharp edges, loose or other material that could damage the coating
Repair divots and minor surface irregularities in blockwork, brickwork or concrete with ARDEX WPM 405 sand cement mortar, ARDEX Render or an ARDEX WPM 300 epoxy mortar
Treat spalling concrete with the ARDEX Concrete Repair range such as ARDEX BR 345
Mix each component individually to a homogenous state using a separate mixing paddle for each
Combine the two components and mix thoroughly at 1:1 by volume until homogeneous, avoiding excessive aeration
Mix only as much as can be used within the 2 hour pot life
Mist dry or highly porous surfaces with a fine spray of water and remove any free standing water
Thin the first coat with up to 5% water on dense surfaces or up to 20% on porous surfaces where penetration is required
Spread the first coat on floors with a squeegee or stiff nylon broom and finish with a medium to long nap roller; roller apply on walls
Apply at 3.0 m2/L per coat, working the material into the prepared surface
Recoat after 4 hours at 25C and 50% RH, applying the second coat undiluted to achieve the required dry film thickness
Apply two coats to 1.5 m2/L in total for moisture barrier or hydrostatic applications; one coat only where used as a primer for ARDEX liquid applied membranes
Broadcast ARDEX Floor Leveller Primer Sand or clean dry 0.5mm sand into the wet second coat at 700 g/m2 to at least 90% coverage where tiles or smoothing cements follow
Sweep and vacuum excess sand after a minimum 24 hours cure
Allow the final coat to cure 24 hours minimum before applying water based membranes, mortars, levelling compounds or decorative coatings
Provide ventilation during the curing cycle in enclosed areas
Wash all equipment in water or water and detergent immediately on completion

Technical Specifications

Product Type: Two component water-based epoxy primer/barrier coating
Colour: Grey or black*
Finish: Semi-gloss (matt with aging)*
Volume Solids: 56% approx.*
Mixing Ratio: 1:1 (Part A:Part B) by volume*
Mixed SG: 1.3 kg/L*
Mixed Viscosity: 12,000 - 20,000 cps*
Wet Film Thickness: 300 micrometers (0.3mm) per coat*
Dry Film Thickness: 150 microns per coat, 300 microns for two coats
Coverage: 3.0 m2/L per coat undiluted; 1.5 m2/L in total to achieve an effective moisture barrier*
Water Vapour Transmission (ASTM E96): less than 10 g/m2/24hrs at 0.3mm DFT over two coats
Hydrostatic Pressure Resistance: 250 kPa, equivalent to 25 metre head of water
Potable Water Compliance: AS4020 and SS375
Moisture Barrier Standard: Two coats at 0.3mm DFT meets the AS1884 requirement for moisture barriers
Pot Life: 2 hours at 25C; 1 hour at 35C*
Recoat Time: 4 hours at 25C and 50% RH*
Full Cure: 7 days at 25C and 50% RH*
Minimum Cure Before Overcoating: 24 hours before water based membranes, mortars, levelling compounds or decorative coatings
Application Temperature: 10C to 35C surface and ambient
VOC Content: 26 g/L*
Thinning: First coat up to 5% water on dense surfaces, up to 20% on porous surfaces; do not thin the second coat
Pack Sizes: 4L kit (2L Part A and 2L Part B); 20L kit (10L Part A and 10L Part B)
Shelf Life: 24 months unopened, stored dry at 23C and 50% relative humidity
Hazard Classification: Part A hazardous chemical, non-dangerous goods, Poisons Schedule S5; Part B hazardous chemical, dangerous goods, Poisons Schedule S5
* Nominal values published by ARDEX in the TECHNICAL DATA table

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Ardex WPM 30020 Ltr Grey

$463.70

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Technical overview

ARDEX WPM 300 (HydrEpoxy) is a two component water-based epoxy primer and barrier coating used as a moisture barrier over damp or green concrete, as a hydrostatic pressure resistant coating on the negative side of walls and floors, and as a primer under ARDEX liquid applied membranes and tile adhesives. It bonds to damp surfaces and green concrete and can prevent rising damp and efflorescence. It is compliant to AS4020 and SS375 for potable drinking water contact and withstands 250kPa of hydrostatic pressure. Two coats at 0.3mm dry film thickness meet the AS1884 requirement for moisture barriers, with a water vapour transmission rate below 10 g/m2/24hrs tested to ASTM E96. The remaining figures are published by ARDEX as nominal values with no test report number quoted.

View full technical data sheet

Key applications

Low water vapour transmission barrier or seal coating over freshly laid or damp concrete
Hydrostatic pressure resistant waterproofing coating to prevent water seepage through walls and floors
Moisture barrier over green concrete before levelling compounds, carpet and tile adhesives
Coating in tanking applications, including potable water containment
Barrier seal coating over damp, green or efflorescence producing concrete before conventional building coatings
Primer for ARDEX Liquid Applied Waterproofing Membranes and ARDEX Tile Adhesives
Nominated primer or coating where substrate moisture exceeds 80% RH (ASTM F2170) or 15 g/m2/24hrs (ASTM F1869)
Moisture barrier for damp concrete subfloors before floor coverings

Surface suitability

Concrete (damp, green or freshly laid hardened concrete accepted)
Concrete block (surface imperfections repaired to a uniform substrate first)
Brickwork (surface imperfections repaired to a uniform substrate first)
Stone
Screed (mist dry or highly porous surfaces with water before application)
Render (two coats at 3.0 m2/L per coat in place of a 7 day dry down before tiling)
Masonry (a minimum single coat is required where moisture exceeds 80% RH to ASTM F2170)
Timber

ARDEX WPM 300 (HydrEpoxy) is not classified as a trafficable coating. Apply only while surface and ambient temperature is between 10C and 35C; the product will cease to cure effectively below 10C and curing is adversely affected above 85% relative humidity. Ventilation must be provided during the curing cycle in enclosed areas. Remove any free standing water before application. Tiling can commence after 24 hours cure but must not exceed a maximum of five days. Take care when sandwiching adhesives between the coating and floor coverings so solvent can escape. Hazardous chemical: may cause cancer, is suspected of causing genetic defects, causes serious eye damage and skin irritation, and is toxic to aquatic life.

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Technical Specifications

Product Type	Two component water-based epoxy primer/barrier coating
Colour	Grey or black*
Finish	Semi-gloss (matt with aging)*
Volume Solids	56% approx.*
Mixing Ratio	1:1 (Part A:Part B) by volume*
Mixed SG	1.3 kg/L*
Mixed Viscosity	12,000 - 20,000 cps*
Wet Film Thickness	300 micrometers (0.3mm) per coat*
Dry Film Thickness	150 microns per coat, 300 microns for two coats
Coverage	3.0 m2/L per coat undiluted; 1.5 m2/L in total to achieve an effective moisture barrier*
Water Vapour Transmission (ASTM E96)	less than 10 g/m2/24hrs at 0.3mm DFT over two coats
Hydrostatic Pressure Resistance	250 kPa, equivalent to 25 metre head of water
Potable Water Compliance	AS4020 and SS375
Moisture Barrier Standard	Two coats at 0.3mm DFT meets the AS1884 requirement for moisture barriers
Pot Life	2 hours at 25C; 1 hour at 35C*
Recoat Time	4 hours at 25C and 50% RH*
Full Cure	7 days at 25C and 50% RH*
Minimum Cure Before Overcoating	24 hours before water based membranes, mortars, levelling compounds or decorative coatings
Application Temperature	10C to 35C surface and ambient
VOC Content	26 g/L*
Thinning	First coat up to 5% water on dense surfaces, up to 20% on porous surfaces; do not thin the second coat
Pack Sizes	4L kit (2L Part A and 2L Part B); 20L kit (10L Part A and 10L Part B)
Shelf Life	24 months unopened, stored dry at 23C and 50% relative humidity
Hazard Classification	Part A hazardous chemical, non-dangerous goods, Poisons Schedule S5; Part B hazardous chemical, dangerous goods, Poisons Schedule S5
* Nominal values published by ARDEX in the TECHNICAL DATA table

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Frequently asked questions

View all FAQs

What substrates can WPM 300 be applied to?

Compatibility
WPM 300 is a moisture-tolerant epoxy primer designed for concrete with high residual moisture (up to 95% RH). It bonds to green concrete, damp slabs, and surfaces with rising damp.
What problem does WPM 300 solve?

Performance
WPM 300 acts as a moisture vapour barrier on concrete slabs prior to installing moisture-sensitive flooring, tile adhesives, or levelling compounds. It blocks rising damp and accelerates project timelines.
How is WPM 300 applied?

Installation
Apply by roller or brush in two coats at 90 degrees to each other. Broadcast clean kiln-dried sand into the wet second coat to provide a mechanical key for subsequent layers.
Is WPM 300 safe to use indoors?

Compliance
Yes. WPM 300 is solvent-free, low-VOC, and low-odour, making it safe for use in occupied buildings and confined spaces.
How thick should the membrane be?

Performance
A two-coat application typically delivers 300-400 microns dry film thickness, which is the minimum required to act as an effective moisture vapour barrier.

Why trade professionals choose Ardex

Ardex is a global leader in high-performance building products, trusted by Australian trade professionals. The range spans liquid and sheet waterproofing membranes, primers, sealers, screeds and repair systems, engineered for lasting results on residential and commercial projects.

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