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Estoflex PU900

High Performance , Single Component, Low VOC Polyurethane Exposed Waterproofing Membrane

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Estoflex PU900 is a flexible single component low VOC polyurethane exposed waterproofing and sealing membrane with Ultra Violet resistant for external application on wall and roof.


To provide a better water and vapour proof in complicating application surface compare to membrane type and ensure better integrity between applied surfaces and waterproofing coating. Areas of application:

  • Reinforced Concrete Roofs
  • Metal Roof
  • Waterproofing of terraces and balconies
  • External swimming pool decks
  • Cement screed


  • Suitable for external areas on wall and roof with Ultra Violet Resistant.
  • Environmentally friendly product with low VOCs content.
  • When fully cured, it forms a tough and flexible membrane, hence eliminating the need for a reinforcing layer.
  • Able to withstand human traffic.
  • Ease of application.
  • Crack bridging capabilities up to 1mm.

Physical Properties

Appearance Liquid
Standard Color Grey / Green
Solid Content, % > 90
Elongation at Break, %
> 550
Tensile Strength, N/mm²
> 3.0
Water Absorption, %
BS1881:Part 122
< 0.1
Adhesion to concrete at 25°C, N/mm2 > 1.5
Shore Hardness > 40
Cure Time, hrs 12 – 24
Touch Dry at 25°C, hrs 4 – 8
Recommended thickness 2 coats at 1.5 mm

Application Instructions

Surface Preparation

STEEL SURFACE: The steel surface must be dry, dry and free of all contaminants. Old coatings, rust, waxes, oils, etc. must be removed by mechanical methods, wire brushing, or abrasive blasting to SA 2 1/2. All blasted surfaces must be coated immediately or before visible rust occurs.

NEW CONCRETE: The surface must be firm, dry, clean, free of dirt, oil, grease, and all other foreign matter. The new concrete must age at least 28 days and a minimum tensile strength of 200 psi is required of the prepared surface before coating. Mechanical methods such as sandblasting, scarifying, or shot blasting should be carried out to remove the weak layer of surface laitance. Acid etching is possible but less desirable. Care must be taken to ensure all residue acid must be removed with clean water before priming.

EXISTING CONCRETE: The surface must be structurally sound, dry and free of all contaminants. Weak or contaminated concrete must be removed until sound concrete is realized. Old coatings, toppings, waxes, oils, etc. must be removed by mechanical methods or acid etching.


No primer is required. However if the substrate is rough and porosity is high, Estoflex Primer is recommended to be applied before application of Estoflex PU900 to ensure good bond strength.


Turn the Estoflex PU900 tin upside down before open. Pre-mix the material with slow speed mechanical stirrer for at least 1 minute.

Apply the first neat coat of Estoflex PU900 on the prepared substrate surface with squeegee, roller or by spray method. Leave it to cure for 12 hours in between each coat. Recommended thickness is 1.5mm in minimum 2 coats.

Important Note

Ensure adequate ventilation is provided when doing work internally.

Packing & Size

Estoflex PU900 22kg (18L) tin
Estoflex Primer 20L pail


Estoflex PU900 1.5L / m2 / 2 coats
Depend on porosity of substrate
Estoflex Primer 4 – 6 m2 per litre
Depend on porosity of substrate


Estoflex PU900 material should be stored below 30ºC out of direct sunlight and rain. All containers should remain sealed until ready to use.

Up to one year in unopened container and stored in a cool and dry elevated place.

Shelf Life

Up to one year in unopened container and stored in a cool and dry elevated place.

Health and Safety

Proper PPE especially safety mask are to be worn during application. In case of eye splashes or excessive skin contact, wash thoroughly with clean water. If ill effects occur, seek medical attention immediately.

Technical Support

Estop offers a comprehensive range of high performance, high quality of product for both new and existing concrete surfaces. In addition, the company offers a technical support package to specifiers, end-users and contractors as well as on-site technical assistance.

Additional Information

Estop manufactures and offers a wide range of complementary products which includes waterstops, waterproofing products. In addition, a wide range of products formulated for repair and refurbishment of spalled concrete are available.