Newton HydroSeal 103 2K - High Performance Waterproof Tanking Slurry

Newton HydroSeal 103 2K - High Performance Waterproof Tanking Slurry

John Newton & Co. Ltd | Cementitious Waterproofing Membrane

Newton HydroSeal 103 2K is a Cementitious Waterproofing Membrane with high adhesion, suitable for the waterproofing of reservoirs, water tanks, below ground structures, podium decks, balconies and parking areas.

Capable of resisting extremely high positive and negative water pressure, HydroSeal 103 2K forms a hard, highly alkaline coating with a degree of elasticity which has greatly enhanced chemical resistance and so is particularly suited for the protection of concrete within sulphate contaminated ground.

Two-Part System, supplied as 6.1kg Bottle of Liquid (Part A) with an additional 23.9kg Bag of Powder (Part B) to make 30kg of Slurry Mixture. Available in Grey colour only.


Newton HydroSeal 103 2K

Newton HydroSeal 103 2K is a two-component, thixotropic, cementitious modified polymer waterproofing membrane with high adhesion, designed for the internal and external waterproofing of concrete and steel elements of water-retaining / water-resisting structures such as reservoirs, water tanks, below ground structures, podium decks, balconies and parking areas.

Capable of resisting extremely high positive and negative water pressure, HydroSeal 103 2K forms a hard, highly alkaline coating with a degree of elasticity which has greatly enhanced chemical resistance and so is particularly suited for the protection of concrete within sulphate contaminated ground.

Newton HydroSeal 103 2K has excellent resistance to the ingress of acid gases, moisture and chlorides to enhance the durability of reinforced concrete and protect highway and coastal structures from chloride attack.

Newton HydroSeal 103 2K is reinforced over static joints and at details and changes of direction with HydroSeal 912-RT.

Product Benefits:

  • Very Waterproof - Resistant to 10 bar Positive and Negative Pressure.

  • Quick Application in one coat to Horizontal Surfaces.

  • Non-toxic when cured.

  • Can be Spray Applied - Up to 2m² per minute is possible.

  • Hard, durable and UV-stable trafficable finish.

  • All year round application to damp substrate.

  • Can be applied at temperatures as low as 5°C.

  • Very low VOC Content.

  • Very high diffusion resistance to Carbon Dioxide Gas and Chloride Ions; equivalent to 100mm of concrete cover.

  • Excellent adhesion to sound prepared concrete substrates and steel.

  • Thixotropic - can be applied at 1 mm to vertical surfaces.

  • High build coating of 2mm eliminates the incidence of small defects seen within thinner membranes.

Typical Applications:

Newton HydroSeal 103 2K is suitable for the Waterproofing of:

    ✔   Podium decks, Balconies and Car Parking areas.

    ✔   Concrete water-retaining structures such as water tanks and reservoirs.

    ✔   Concrete earth-retaining foundation walls to both the positive and negative side.

    ✔   Internal concrete surfaces of walls and rafts or slabs to earth-retained structures such as habitable basements, car parks, plant rooms and lift-pits.

    ✔   Concrete temporary lay down and working areas.

Substrate Suitability:

Suitable Substrates

Correctly prepared substrates of the following:

  • Concrete of at least 20MPa

  • Steel

  • Structural Masonry / Mortar

Suitable Surfaces

Waterproofing of:

  • Walls - Positive Pressure & Negative Pressure

  • Slab / Raft - Negative Pressure

  • Soffit - Negative Pressure

  • Decks & Balconies - Positive Pressure

Ancillary Products:

  • Newton HydroSeal 903 Primer - Primer for Concrete.

  • Newton HydroSeal 905-CM - Curing Membrane to prevent accelerated drying during hot or very windy conditions.

  • Newton HydroSeal 912-RT - Reinforcement Tape for static joints and construction joints.

  • Newton HydroSeal 107 Elastic 2K - Flexible Waterproofing Membrane for use with HydroSeal 912-RT above shrinkage joints.


Health & Safety Recommendations:

Take the usual labour hygiene into account.

PPE should be worn during application. See our Safety & PPE Products.

Consult label and material safety data sheet for more information.


Construction - General

The construction should conform with current Building Regulations, British Standards and relevant Codes of Practice.

Construction - New Concrete

New concrete to earth retaining structures should be designed by a Structural Engineer to EN 1992 (Formerly BS 8110). A shuttered finish to vertical surfaces is suitable for HydroSeal 103 2K.

Horizontal concrete surfaces should have a surface finish to should have a surface finish to at least Class of finish U3 and preferably to class U4 or U5 as documented in ‘General Specification for Civil Engineering Works’ section 14: ‘Formwork and Finishes to Concrete’, namely a ‘Uniform, dense and smooth surface’.

Float marks should be avoided as these will impact on the cost of correct surface preparation.

HydroSeal 103 2K can be applied to new concrete:

  • The concrete is at least 20 N strong

  • The concrete can be prepared using conventional mechanic preparation methods to remove laitance to floors and release agents to walls

Construction - Mortar

Walls should be designed by a Structural Engineer to withstand the load of the retained earth as well as the expected water pressure as defined by BS 8102:2009.

The mortar joints should be pointed flush to the surface of the wall.


Surface Preparation - General

Generally the surfaces to be waterproofed must be structurally stable, clean, dry and free from release agents, dust, laitance, oils, paints or other forms of contamination.

Substrate damage, deterioration, cracks, voids, and holes should be repaired and filled prior to installation of the waterproof membrane with Newton HydroSeal 203-RM repair mortar.

Deep or structural cracks should be inspected to confirm if they are live or dormant.

Suitable repair by qualified personnel is recommended.

Surface Preparation - Concrete Walls

Jet washing with minimum pressure of 2500 PSI should be used to remove release agents and surface contamination to concrete walls. Adding mild detergents to the jet wash water will improve effectiveness.

Fine surface cracks and blow-holes should be filled with sand/cement using a bag rubbing technique. Tie-Bolt holes should be filled with Newton HydroSeal 203-RM.

Surface Preparation - Mortar Walls

Joints should be flush pointed. If they are not, re-point or apply a smoothing coat of sand/cement render with Newton HydroSeal 908-LB mixed into the gauging water at 1:2.

Porous block walls should be filled by bag-rubbing with sand/cement or Newton HydroSeal 105 1K.

Existing walls of block or brick will require wall surface preparation such as grit blasting or scabbling to ensure all surface contaminants are removed and that a good ‘key’ is achieved. Remove snots.

Surface Preparation - Concrete Floors

In all cases, concrete floors should be ground or sand blasted to remove laitance. Vacuum clean after.

If the concrete floor needs to be levelled, please speak to the Newton Waterproofing Technical Department who will advise on the correct levelling product.

Large holes or indentations should be filled Newton HydroSeal 203-RM.

Joints & Changes Of Direction:

Reinforce static joints with Newton HydroSeal 912-RT. Over shrinkage joints, use Newton 107F bedded into 25mm wide masking tape to create delamination.

With movement joints, lap the Newton HydroSeal 103-S into the joint and then use standard Newton FlexProof 106 movement joint detail.


Walls & Soffits: Prior to slurry tanking, porous substrate should be sealed with sand / cement using a bag rubbing technique.

Internal Slabs & Rafts: Porous substrate should be sealed with Newton HydroSeal 903 Primer.

External Decks: Should be primed with Newton HydroSeal 903 Primer.



Newton HydroSeal 103 2K should be mixed with a high quality mixer & stirrer, such as a Collomix DLX Stirrer or Collomix KR Stirrer matched to a Collomix XO1 Hand Mixer or XO4 Hand Mixer.

  • Shake Part A (Bottle) and pour into clean container.

  • Add Part B (Powder) slowly whilst mixing slowly.

  • Mix for 5 minutes until smooth, entrapping as little air as possible.

  • Continuously scrape sides to prevent lumps forming and to ensure all of Part A is mixed with all of Part B.

  • Mix for a minimum of 5 minutes and use without delay.

Application Methods:

    ✔  Squeegee

    ✔  Roller

    ✔  Pin Leveller

    ✔  Brush

    ✔  Trowel

Application Rate:

The membrane is applied to a total thickness of 2.0 mm, which requires an application rate of 3.6 kg/m².

Walls & Soffits

Application is by two coats, each of 1.8 kg/m².

Horizontal Surfaces

Application is by two coats, each of 1.8 kg/m² or by a single coat of 3.6 kg/m²

At a thickness of 2.0mm, a 30kg composite pack covers a total surface area of 8.3m²

Product Application:

The mixed slurry can be applied by Brush, Squeegee, Roller, Trowel or Pin Leveller.

Ensure that air is not entrapped into the surface of horizontal applications by using a spiked roller as soon as the product is placed. Apply as explained within the Application Rate Section above.

With two coat applications, the second coat can be applied when the first coat is still ‘green’ and slightly tacky and up to five days after the first coat has been applied.

After five days, the first coat will need to be washed to remove dust. In addition, a primer of Newton HydroSeal 908-LB mixed 1:1 with water can be applied to enhance adhesion of the second coat to the first.

Typical Detail

Pot Life & Further Use:

HydroSeal 103 2K is a two-part product and a chemical curing reaction starts as soon as the two parts are mixed.

Pot life is 30 minutes at 20ºC. Product must be used before it starts to go off / over thicken.


For curing / drying times please refer to Page 2 of the Technical Data Sheet, found in the 'Data Sheets' Tab.

Newton HydroSeal 103 2K is a cement-based product and requires curing. Accelerated drying is to be avoided.

If the conditions are hot, sunny and/or very windy the finished membrane must be protected from accelerated drying with the application of Newton HydroSeal 905-CM, a simple to apply liquid curing membrane.

In floor and deck applications, coloured sands or grit can be cast onto the surface to provide effective curing, whilst also creating an abrasion and slip-resistant finish.

Curing must commence within 10-15 minutes of the completed application of the coating.

Life Expectancy:

When specified, installed and protected in accordance with the Data Sheet and Application Guides, is fully and permanently isolated from UV light and physical damage or wearing, and only to those substrates confirmed within, Newton HydroSeal 103 2K has a service life that can be equal to the design life of the structure.

If the membrane is to be exposed, HydroSeal 103 2K is very resistant to mechanical and chemical wear. However, it is impossible to accurately determine the life expectancy as this is dependent on the type, frequency and aggressiveness of the wearing agents. 

HydroSeal 103 2K is guaranteed to resist weathering for up to 10 years. The membrane is not UV colour stable and will slightly fade in colour over time, and it may take a few months for the colour to be consistent. Over time discolouration due to weathering may take place, but the membrane will be serviceable.

Protective wearing coats should be considered. If protected HydroSeal 103 2K has a service life that can be equal to the design life of the substrate is applied to.


  • Do not apply prior to rain - Please refer to information within the Curing Table on Page 2 of the Technical Data Sheet.

  • Do not apply at temperatures lower than +5°C or higher than +30°C.

  • Always use the correct preparation and priming of the support substrate as directed above.

Data Sheets

Technical Data Sheet

Declaration of Performance (DoP)

Safety Data Sheet

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