NBS Source
KRYTON Krystol Internal Membrane (KIM-HS)

KRYTON Krystol Internal Membrane (KIM-HS)

RIW Third party certifications:
  • BBA Agrément Certificate

    BBA Agrément Certificate

    Certificate type

Concrete waterproofing and durability enhancing admixture.

Jump to:
+44 (0)1753 944200 www.riw.co.uk


Suitable for providing permanent protection for all concrete that will be subject to water pressure, such as:

  • Below grade parking structures, basements, elevator pits and foundations of high-rise towers;
  • Recreational facilities such as aquatic centres, aquariums, zoos, water parks and marinas;
  • Architectural water features such as fountains and waterfalls;
  • Water containment reservoirs, water treatment tanks, sewage and manholes;
  • Traffic tunnels, below grade pipelines and subway tunnels;
  • Bridges, dams and highway infrastructure;
  • Concrete homes including basements, foundations, swimming pools, decks, bathrooms, garages and exteriors;
  • Properly designed roof tops and plaza decks.

KIM is an effective waterproofing system for rigid concrete structures only and may not reliably seal cracks and joints that experience variable loading or repeated movement.


A hydrophilic crystalline admixture used to create permanently waterproof concrete. The product lowers the permeability of concrete and is used in place of surface applied waterproofing membranes. By stopping the transmission of water through concrete, the product adds durability and longevity to concrete by protecting it against chemical attack and corrosion of reinforcing steel.

When added to concrete, Krystol chemically reacts with water and un-hydrated cement particles to form insoluble needle-shaped crystals that fill capillary pores and micro-cracks in the concrete and block the pathways for water and waterborne contaminants. Any moisture introduced over the lifespan of the concrete will initiate crystallization, ensuring permanent waterproofing protection.

Features and benefits:

  • KIM is a permeability reducing admixture for hydrostatic conditions (PRAH).
  • Replaces unreliable exterior membranes, liners and coatings.
  • Easily added directly to ready-mix truck or at batch plant.
  • Self-seals hairline cracks up to 0.5 mm (0.02 inches).
  • Effective against hydrostatic pressure up to 140 m (460 ft) of head.
  • Impervious to physical damage and deterioration.
  • Safe for contact with potable water, certified by NSF to NSF/ANSI Standard 61.
  • Reduces concrete shrinkage and cracking.
  • Provides excellent resistance to waterborne chemicals such as sulphates, chlorides, and acids.
  • KIM has been tested and certified safe for concrete drinking water containment by NSF International.
  • Compatible with self-compacting concrete (SCC).
  • Permanently waterproofs concrete.
  • Protects concrete and reinforcement from harsh environments.
  • Increases the durability and lifespan of concrete.
  • Lowers the cost of waterproofing by up to 40%.
  • Significant reduction to the construction schedule.
  • Reduces the cost of maintenance and repairs.
  • Increases revenues with a larger building footprint.
  • Essential for blind-wall and shotcrete applications.

Plastic properties:

  • Water/ cement ratio (KIM Concrete 2% wt Cement): 0.47.
  • Slump - 0 min to BS EN 12350-2: 65 mm.
  • Slump - 30 min to BS EN 12350-2: 45 mm.
  • Air content to BS EN 12350-7: 0.9%.

Hardened properties:

  • Freeze/ thaw expansion to BS 5075-2: Reduced 87%.

Consult technical literature for details on workability, permeability, corrosion resistance, sulphate resistance, self-sealing performance, chloride ion content and shrinkage and crack reduction.

General information




Pr_20_31_03_96 Waterproofing mortar admixturesPrimary


E10/418 Proprietary admixture

Specification data - Waterproofing mortar admixtures Enhanced data

Third party product certification

Agrément certificate.

Product Reference

KRYTON Krystol Internal Membrane (KIM-HS)


Light grey powder.

Particle size

40-150 μ.


Bulk density ~1.4 g/cm³ (88 lb/cu.ft); Plastic density to BS EN 12350-6, 2420 kg/m³

Specific gravity



Plastic: No change or slight increase; Hardened: To BS EN 12390-3, increased 8% (28 days).

Water permeability coefficient

(Taywood/ Valenta)

Reduced 70%.


(Drying shrinkage)

To BS 1881-5, reduced 25%.

Flexural strength

To BS EN 12390-5, increased 7% (28 days).

Modulus of elasticity

To BS 1881-122, increased 16%.


Kryton KIM

Kryton KIM

Third party certifications

  • Certificate: 05/4217