Polyurea Rayston: Pure Polyurea Spray Membrane for Waterproofing
Polyurea Rayston is a two-component pure polyurea spray membrane by Krypton Chemical. Hot-sprayed with plural-component equipment, it cures in seconds into a seamless, elastic and crack-bridging waterproofing layer.
- Product: Polyurea Rayston
- Type: pure polyurea, hot spray
- Mix: A=1 : B=1.17 by weight / 1:1 by volume
- Gel time: 4 s at 25 °C
- Colours: light grey, dark grey, rust red, blue
One continuous membrane with no joints or overlaps, sprayed on site and ready to take water within minutes of application.
01 · Uses
Where a pure polyurea spray membrane like Polyurea Rayston is used
- Waterproofing of concrete structures, foundations and roofs, including structures permanently exposed to water.
- Foundations designed as a barrier against radon gas.
- Wastewater treatment plants, tunnels and channels, and dam repair.
- In-situ liners: the membrane can be combined with selected geotextiles to build continuous, watertight linings.
Its high elasticity and crack-bridging ability make it a good fit for substrates that need a fast-curing, fully continuous layer. If you are new to the chemistry, this overview of polyurea is a useful starting point; for tank work, see our engineering guide to lining drinking water tanks with polyurea.
02 · Application
How Polyurea Rayston is hot-sprayed
The two components are heated and mixed inside the spray equipment at A=1 : B=1.17 by weight (1:1 by volume). Gel time is 4 seconds at 25 °C, so the membrane builds thickness fast and is walkable almost immediately.
The substrate must be flat, cohesive, clean and dry, with a temperature between 10 °C and 40 °C and moisture content below 4%. Component A can be tinted with Pigment Spray paste; for UV protection the datasheet calls for an Impertrans or Colodur topcoat.
In practice the sequence is: substrate preparation, priming, mixing, hot spraying, then a check of thickness and continuity. Typical substrates and system build-ups are shown in our Polyurea Rayston foundations case and the Tenerife stadium stands project.
Technical datasheet: Polyurea Rayston TDS (PDF) · Polyurea waterproofing systems
03 · Technical data
Polyurea Rayston technical data (TDS values)
Max. elongation
324%
Tensile strength
16.2 MPa
Shore hardness
87A/35D
Watertight (EN 12390-8)
5 bar
Polyurea Rayston properties
- Max. elongation: 324%
- Tensile strength: 16.2 MPa (UNE EN ISO 527-1/3)
- Tear strength: 69 N/mm (ISO 34-1)
- Hardness: 87A/35D (ISO 868)
- Liquid water permeability: 0.002 kg/m²·h0.5 (EN 1062-3:2008)
- Watertightness: 5 bar, 50 m water column (EN 12390-8)
Uses and approvals
- Waterproofing of concrete, foundations, roofs and wastewater structures
- Fast-curing, hot-sprayed membrane
- CE marking to EN 1504-2 and European Technical Assessment (ETA) to ETAG 005
04 · Performance
Polyurea Rayston performance in waterproofing
After curing, Polyurea Rayston becomes a solid elastomeric membrane with 324% maximum elongation and a tensile strength of 16.2 MPa. Hardness is 87A/35D (Shore hardness, ISO 868) and tear strength 69 N/mm (ISO 34-1).
The membrane stays watertight at 5 bar – a 50 m water column – under EN 12390-8, and its liquid water permeability is just 0.002 kg/m²·h0.5. That is why it is specified for foundations, roofs, water-retaining concrete and metal structures, provided the substrate is prepared and primed correctly. For a comparison with hybrid systems, read pure polyurea vs hybrid on roofs.
Application data
- Mix ratio: A=1, B=1.17 by weight; A=1, B=1 by volume
- Gel time: 4 s at 25 °C
- Substrate temperature: 10–40 °C
- Substrate moisture: below 4%
- Colour: Pigment Spray paste added to component A
- UV protection: Impertrans or Colodur topcoat
05 · FAQ
Polyurea Rayston: frequently asked questions
What is Polyurea Rayston?
A two-component pure polyurea membrane from Krypton Chemical, applied by hot spraying to form a seamless, elastic waterproofing layer that cures in seconds.
How watertight is Polyurea Rayston?
The datasheet reports it watertight at 5 bar (a 50 m water column) to EN 12390-8, with liquid water permeability of 0.002 kg/m²·h0.5 (EN 1062-3).
Does Polyurea Rayston need a topcoat?
For UV protection, yes: the datasheet recommends an Impertrans or Colodur topcoat on exposed surfaces.
More Impermax and Rayston polyurea products
Every product page in this series is based on its official Krypton Chemical technical datasheet.
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