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MS Application FORMDEX PLUS for basement by dry sprinkling

( 01-10-2014 - 08:55 AM ) - Views: 1564

FORMDEX PLUS  is  a  unique  chemical  treatment  for concrete corrosion protection and waterproofing by crystallization. Manufactured in the form of a dry powder compound FORMDEX PLUS protects and waterproofs concrete by the process of osmosis. Because the chemicals in FORMDEX PLUS have an affinity with water the crystalline formation migrates throughout the pores and capillary tracts of concrete sealing the concrete against intrusion of water, chemicals, sewage and other harmful chemicals. The active chemicals penetrate the concrete and react with free lime and moisture to form a subsurface membrane effectively sealing the concrete. The layer formed allows the passage of water vapour from the inside of the structure (the concrete breathes) whilst waterproofing/sealing the surface against sea water, aggressive ground waters, waste water and certain chemical solutions.

FORMDEX PLUS can be applied to all structurally sound concrete. Typical areas of application are : sewage and waste water treatment  tanks, reservoirs, tunnels, manholes, caissons, underground vaults and structures, foundations, parking decks, planter boxes, roof gardens, podiums and swimming pools. Contite Seal provides concrete protection against waste water, sewage, certain chemical solutions, dilute intermittent acids, carbonation, salt water, sulphates, and other harmful materials.

Advantages   include:

• Resistant to most aggressive substances in the pH range

3-11 constant contact, and 2-12 periodic contact.

• Protects concrete and steel rebar from deterioration.

• Non toxic. No solvents. No harmful vapours.

• Can apply to green or moist concrete.

• Fast tracks projects.

• Becomes an integral (internal) part of the concrete therefore it does not rely on the coating to protect or waterproof concrete.

• Seals minor shrinkage cracks and will reactivate after many years in the presence of water.

• Does not require costly surface priming or leveling prior to application as for other coatings.

• Cannot puncture, tear or come apart at  the seams as with other protection systems.

  • Less costly to apply than other systems.

  • Does not require protection from backfill.

  • Use in underground structures from the inside (negative side).

  • Extensively used for concrete repair work and is particularly useful to apply on the negative side of water retaining or underground structures both above and below grade.


Concrete surfaces to be treated must be clean and free of laitance, dirt, films, paint, coatings or other foreign matter. The surfaces must also have  an  open capillary system for the FORMDEX PLUS treatment. If surfaces are too smooth the concrete should be acid etched, lightly sandblasted or waterblasted.

Structural defects such as cracks, faulty construction joints and honeycombing should be routed out to sound concrete and repaired. Horizontal surfaces should preferably have a rough wood float or broom finish.

Wetting Concrete:

Prior to the application of FORMDEX PLUS, concrete surfaces must be thoroughly wetted with clean water (concrete should be saturated) to aid the proper curing of the treatment and ensure the growth of the crystalline formation deep within the pores of the concrete. Excess surface water should be removed before the application.


Mix one 25 kg bag with 6.50-7.00 litres of clean water.  Do not mix too wet otherwise the mix may crack & spall when drying. Always add powder to water. Mix until smooth and lump free.  Do not rework stiff material by adding more water.  Mix sufficient material to use within 30 minutes.


Slurry  coat:

Apply FORMDEX PLUS with a stiff fiber brush. Scrub well into the damp wall filling all pores and finish with final strokes in one direction. Keep a wet edge. After the first coat has set but while it is still green apply a second coat, if this is not possible prewater before application of the second coat.

Dry Sprinkling Method:

For  Newly  Poured  C o n c r e t e  -  Use  FORMDEX PLUS directly from the container. Wearing rubber gloves distribute the powder evenly by hand over the freshly poured concrete at 1.6 kg/m2  before the final trowelling work. It is recommended to distribute approximately 50% of the powder in one direction with the remaining 50% at right angles to the first application.

Release the powder as close to the wet concrete as is possible. A roughened finish is recommended on the first coat to ensure adequate adhesion of the second, finally trowel the concrete to the required finish.

For Under Slab Waterproofing - Ensure that all debris is removed from lean concrete’s surface including soil, grease, oil etc. Either apply in slurry coat or sprinkle by dry shake method on to the concrete just before pouring the slab at 1.2 kg/m2 . If delays in pouring concrete keep FORMDEX PLUS moist by mist/fog spraying water.

Construction joints, cold joints and non-leaking joints greater than 0.25 mm wide must be routed out to a minimum 25 mm wide by 25 mm in depth to reach sound concrete, the profile of the routed joint should form a “U” shape.

FORMDEX PLUS Mortar should be mixed with water to provide a dry pack material which must then be rammed into the routed out joint.

New Construction Joints:

Install Bentonite Waterstop NT at the centre of the joint at least 7.5 cm. from the concretes exterior. A dry pack sealing strip of FORMDEX PLUS Mortar should be rammed into a prepared rout at least 25 mm. by 25 mm. 

Leaking Cracks:

Should be prepared as above to form a chase of 25mm wide to approximately 35 to 50mm deep. Remove all debris  from the work area before proceeding with thorough saturation of the area prior to the next stage of the works.

Dry pack FORMDEX PLUS Mortar into the prepared rout.

The FORMDEX PLUS treatment should be applied with a semi-stiff bristle brush, janitor’s broom (for large horizontal applications) or with specialized spray equipment.

For more information please contact us as bellow address:


Head Office  : 6C6 Nam Long Residential, Ha Huy Giap St - Thanh Loc Ward - Dist 12- HCMC

Mobile: 0909080729      Tel: (+84.8)54453667, (+84.8)54476808     Fax: (+84.8)54453668   

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