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weber waterseal321

weber waterseal321
weber waterseal321

Product benefits

  • Elastomeric cementitious waterpoof coating
  • Internal and external applications
  • Protects concrete when exposed to extreme climatic conditions
  • Easy brush applied

It is two component high performance acrylic polymer modified cementatious membrane coating for under tile waterproofing

Product Description and Features

Product Description

weber waterseal 321 is a two component polymer modified elastromeric cementitious waterproof coating that requires only clean water to be added at site for easy brushable consistency. It protects concrete cementitious substrate and advance dry wall partition against water peetration. weber waterseal 321 protects and enhances the durability of the structure even which are exposed to costal and extreme climatic conditions. Easy to apply on surfaces by stiff brush, roller or trowel to form a flexible waterproof coating.

Key Features

  • Provides high water impermeability at 5 bar pressure
  • It can be used for both internl and external application
  • Excellent bonding to masony, concrete and non porus suface
  • It provides resistance against the attack of carbon dioxide and chloride ion diffusion
  • Suitable for retaining structure against water ingress
  • Non toxic in nature
  • Easy to apply and econimical in use
  • Breathable in nature allow the wter vapour to esape from the structure, has good crack bridging properties.
  • it can be applied for existing and new surfaces.


  • weber waterseal  321 can be applied to surfaces which are smooth, porous and non porous. Surfaces like cast concrete, glazed surface, plastered, fiber cement board and moisture resistant plasterboard can be protected against the water penetration to provide waterproofing surfaces.
  • It can withstand normal traffic movement and incase of high traffic thinckness of coating is to be increased with protection layer of screed.
  • weber watersal 321 can be applied as coating and to protect tile rod to provide water tightness.
  • weber waterseal 321 can be applied at
  • Wet areas in kitchen sink
  • Balconies and terraces
  • Sunken slabs in bathrooms and toilets
  • Slopped and flat roofs
  • Internal wal dampness areas
  • Water tanks
  • Submerged conditon areas 

Technical Parameters


Color                                                              Grey

Pot Life  at 27 deg C                                        30 - 40 mins

Mixed density                                                  1.70 gm/cc

Bonding strength to concrete                          >1.1Mpa

Water permeability @ DIN 1048                        5 bar

Toxicity test @ IS 6582                                    No toxicity

Tensile strength @ ASTM 638                        > 0.4Mpa

Application temperature                                    10- 35 @ deg C

Rocoatable                                                       Yes


Send or download the documentation

You can either send the documentation to en-email address, or download it.

Preparation and Application

Direction For Use


  • The application surfaces need to be cleaned to remove dirt, dust, latence, loosely attached particles and bond inhibiting componds with help of a wire brush.
  • in case of high grade concrete water prssure jet and grit blasting can be used to clean the surfaces.
  • Incase of oil and grease residue on the structure can be cleaned with solvent, surfactant followed by ater cleaning
  • The dust generated during surface preparation ideally vaccum cleaner o be used.
  • Before application of coating the surface needs to be well staurated with clean water and should be touch dry for the coating to be applied.


  • weber waterseal 321 is a 2 component consisteing of grey color free floing powder and liquid polymer to be mixed along with clean water by weight in ratio 3:1 and tobe applied on surfaces.
  • Sowly add filler to he liquid and mix, using a slow speed drill fitted with a suitable paddle to achieve lumpfree brushable consisteny
  • Mix the components for 3 - 5 mins with addition of clean water as per mxing ratio and withstand for 2 mins to regain application consistency.
  • Do not extrendpt life by adding water to the mix when it has dried.
  • Bush the mixture frmly on the prepared surface, care must be taken not to spread the material too thin on the surface using small size 4" - 6" brush
  • Allow atleast 4 to six hours to cure before applying subsequent coats, the second coat to be applied in the direction of 90 deg to first coat to achieve a min 1 mm thickness
  • Allow the water proofing coat to dry for 48 - 72 hours subjected to water leakage test.
  • Incase of surfaces subjected to heavy traffic movement, a higher thickness of1.5 - 2mm is to be applied followed by protection screed.

Shelf Life

1year from the date of manufacturing, for unopened cans, stored in dry condition.


15kg  component A and 5L component B


1.9 - 2 kg/sqm for 2 coats. consumption may vary depending on surface conditions.


Milky White