CJSA Hydro-Stop® CJ-5000

CJSA Hydro-Stop® CJ-5000 Chloroprene Rubber Hydrophilic Waterstop is produced from a unique hydrophilic chloroprene rubber sealing compound which expands in a controlled fashion when exposed to moisture to form a gasket and compression seal inside the concrete joint, to give a permanent flexible watertight seal. Hydro-Stop® CJ-5000 is capable of sealing heads of water up to 60 metres (6.0 Bar) in ground and salt water environments.

Hydro-Stop® CJ-5000 is ideal to be used in horizontal and vertical construction joints for cast in-situ concrete structures and pre-cast elements.

Hydro-Stop® CJ-5000 complies to NSF/ANSI Standard 61 Drinking Water System Components – Health Effects, ensuring Hydro-Stop® CJ-5000 is safe for use in drinking water applications. Therefore, it is suitable to use in various potable water retaining structures like water tanks, swimming pools and reservoirs.

  • Excellent sealing capabilities against high hydrostatic head pressures in potable and salt water environments.
  • Provides a permanent, flexible gasket and compression seal inside the concrete.
  • Available in a number of different sizes, shapes and profiles to suit the specific structure’s joint requirements.
  • High quality, non-biodegradable compounded chloroprene hydrophilic rubber that provides long-term durability and integrity to the joint and structure
  • Ability to expand up to 200% in contact with water and over 100% expansion in salt water.
  • Has been tested to withstand over 60 metres (6.0 Bar) of hydrostatic head pressure.
  • For use in many different types of applications but especially suited for water retaining structures where direct water pressure is applied against the concrete joint.
  • Can be applied directly on to smooth concrete surfaces or rough surfaces with the use of a recommended adhesive.
  • Unaffected by repeated wet and dry cycles.
  • Non-toxic, requires no special handling and can be used in potable water structures.
  • Fast and simple to install.
  • For use in horizontal and vertical construction joints.
  • No on-site welding required.
  • NSF Certified for use in potable water applications.

Note: The product’s design and performance, its intended use, installation and final confirmation and approval for use, must be provided by the project’s Design Engineer and Project Manager.

Note: The above Physical Property results are obtained from our internal Certificate of Analysis (COA) testing from a specific batch. Material properties can vary between batches.

Figure 1: Expansion rate properties of Hydro-Stop® CJ-5000 in various solutions

Figure 2: Before and after expansion of Hydro-Stop® CJ-5000

Note: The above test reports are available upon request.

Note: Refer to above minimum concrete cover requirements. Please refer to CJSA for further information.

Due to expansive forces, Hydro-Stop® CJ-5000 should be both detailed and installed with a minimum 50mm clear cover to the face of the concrete. Expansion rate can vary in salt and contaminated water. Increase cover when using light weight, low strength concrete. Not for use where excessive shrinkage of the concrete may occur at the joint faces. Do not stretch the Hydro-Stop® CJ-5000 during installation. Not for use in movement (expansion, isolation and contraction) joints.

Hydro-Stop® CJ-5000 – 20mm x 10mm x 10m rolls (8 rolls per carton)

Hydro-Stop® CJ-5000 requires a minimum 50mm cover of concrete from the outside edge.

For a smooth concrete surface:

  1. Make sure the surface of the concrete is clean and dry, and brush off any dust or debris from the area where the Hydro-Stop® CJ-5000 is to be applied. If there are any high or sharp points of concrete protruding, then remove these with the use of a hammer or similar tool. If there are any holes in the concrete surface bigger than 10mm in depth or diameter, then fill these with a small application of Leakmaster hydrophilic sealant, prior to placement of the Hydro-Stop® CJ-5000. Once the surface has been prepared accordingly, brush a thin coat of CJ-100 Adhesive 30mm wide onto the concrete surface and one thin coat to the surface of the Hydro-Stop® CJ-5000.
  2. Once both surfaces of where the adhesive was applied, are touch dry, with the use of your thumbs or heel of your hand, firmly press a continuous bead of Hydro-Stop® CJ-5000 into position, making sure you achieve full contact with the adhesive on the concrete surface. Do not stretch the Hydro-Stop® CJ-5000 when applying it into position.
  3. Use a neat, firm butt join to join Hydro-Stop® CJ-5000 together and then apply a 10mm bead of Leakmaster over the top of the join and down each side of the join. This type of join is used for continuous placement of Hydro-Stop® CJ-5000 and for any intersection joins.
  4. Check to see that the Hydro-Stop® CJ-5000 has fully adhered to the concrete surface. There must be no visible gaps under the Hydro-Stop® CJ-5000 after installation.
  5. The protective paper layer cover on the Hydro-Stop® CJ-5000 can be removed any time prior to the second pour of concrete taking place.
  6. Placement of the second pour of concrete can be applied once the adhesive has dried. Upon pouring, make sure the concrete is properly compacted and vibrated around the Hydro-Stop® CJ-5000 .
  7. If the Hydro-Stop® CJ-5000 has been exposed to water (moisture) prior to the second pour taking place, check for pre-expansion. If the product has pre-expanded, then remove that section and replace with a new length of Hydro-Stop® CJ-5000 .
  8. For vertical construction joints and overhead applications, it may be necessary to also secure the Hydro-Stop® CJ-5000 with nails, placed approximately every 250mm apart. This is usually only required as extra security if you need to pour your concrete prior to the CJ-100 Adhesive drying completely.
  9. If the Hydro-Stop® CJ-5000 is going to be exposed to moisture or submerged in water longer than 5-7 days, then an additional coating of CJ Expansion Delay Coating may need to be applied to all exposed areas. Consult CJSA for further advice.

For a rough concrete surface:

  1. For rough concrete surfaces where the Hydro-Stop® CJ-5000 cannot conform to the irregularities of the surface, the use of Leakmaster hydrophilic sealant must be applied instead of CJ-100 Adhesive. Depending upon the roughness of the concrete, apply a continuous 10mm to 20mm diameter bead of Leakmaster onto the surface. Once applied, with the use of your thumbs or heel of your hand, firmly press a continuous bead of Hydro-Stop® CJ-5000 into position, making sure you achieve full contact with the Leakmaster on the concrete surface. Do not stretch the Hydro-Stop® CJ-5000 when applying it into position.

Note: All other points above from number 3 to 9 also need to be applied.

Step 1

Hydro-Stop® CJ-5000 is to be adhered to the 1st pour of concrete with CJ-100 Adhesive. A clean, dry surface free from dust, debris, etc, is required. Apply one application of adhesive onto the concrete surface and one application onto one side of the Hydro-Stop® CJ-5000.


Once both surfaces are touch dry, lay the Hydro-Stop® CJ-5000 into position and push firmly down with your fingers. If the surface is rough then you may need to use a firmer hand pressure to make sure that the product has full contact with the surface of the concrete.


  • Exposure & Water Immersion Expansion in Potable Water
  • Exposure & Hydrostatic Head Pressure (cyclic wet & dry) in Potable Water
  • Water Immersion Expansion in Salt Water (In-house)

Note: The above test reports are available upon request.

Waterstops where shown on the drawings shall be Hydro-Stop® CJ-5000 Chloroprene Rubber Hydrophilic Waterstop as supplied by CJSA. The waterstop is to have a built-in expansion control system to minimise any pre-expansion prior to the second pour taking place and be able to withstand up to 60 metres (6.0 Bar) hydrostatic head pressure resistance. The waterstop is to be placed in accordance with the manufacturer’s installation guidelines, and the design engineers specification.

In confined spaces or in still air conditions, the use of a ventilation fan or suitable respirator should be used, and the advice and approval of the Site Safety Supervisor is essential. For further information or advice on health and safety precautions, safe handling, storage and correct disposal of products, please refer to the most recent product Safety Data Sheet (SDS), which is available upon request.

The information and the recommendations relating to the application and end use of this product are given in good faith and are based on the information provided by the manufacturer of the product and/or the Company’s current knowledge and experience in connection with the product when properly stored, handled and applied under normal conditions and no liability of final function at the job site is assumed. In practice, the differences in materials substrates and actual site conditions are such that no warranty in respect of merchantability of or fitness for particular purpose, nor any liability arising out of any legal relationship whatsoever, can be inferred either from this information, or from any written and/or oral recommendations, or from any other advice offered by the Company.

The Company also has no express or implied knowledge of any particular purpose for which the product is required and any such information given will not be taken into account in the supply of this product. No responsibility or liability by the Company will be accepted for misuse, misreading or derivation from recommended guidelines in respect of this product and the user shall determine the suitability of the product for his intended use and assume all risks and liability in connection therewith. The information contained in our brochure may change at any time without notice. Any use of this product; Hydro-Stop® CJ-5000 in any application should be approved as suitable for use/application by the Design Engineer and Project Manager.