Surface preparation for polymerized white cement based putty
During application of Weberwall finecoat – a white cement-based polymer modified putty, surface preparation is one of the most critical steps where one needs to take due diligence to get the best results. An ideal substrate for application of weberwall finecoat is free from dust, dirt and loose material, with perfect evenness and saturated condition at the time of application. While dust particles or loose materials can create an issue in obtaining desired adhesion strength, surface unevenness can reduce the coverage and make solution costlier for the same desired output.
In this article, we have covered possible variations in substrate conditions and their suitable remedies.
If a substrate is a new surface, then chances are very high that it will be having dust, dirt and other foreign materials which can impact the bonding strength of weberwall finecoat severely. Also if there are any cracks, voids and damages; they can greatly hamper the coverage and performance of weberwall finecoat. Clean loose particles, dirt, grease and traces of adhering material from the wall surface with the help of wire brush, putty blade or sandpaper. For uneven surfaces, re-plaster it with weberwall premium plaster to make them even. In case of cracks in base plaster, it is recommended to ﬁll it using weberwall crackbond & application of weberwall finecoat can be done after 24 hours.
For loose plastered areas, remove the defective material and re-plaster the area with weberwall premium plaster and allow for adequate curing. Such condition appears in generally old unpainted surfaces.
Areas with dampness or moisture in the substrate can have organic growths like fungus, algae or moss. Such organic growths are a hindrance between substrate and layer of weberwall finecoat. For areas affected with organic growth, any previous growth of fungus, algae or moss needs to be removed thoroughly by vigorous wire brushing and cleaning with water.
Old painted surfaces have a layer of paint/ dust particles inhibiting adhesion of a fresh layer of weberwall finecoat to the substrate. To remove such old paint, one can use sandpaper/ wire brush. After complete removal of the old paint layer, the surface should be washed with water to remove any remaining dust particle. Before application of weberwall finecoat, the surface must be in a saturated condition.
Very rough surfaces can directly hamper the surface finish and coverage of Weberwall finecoat. Proper levelling shall be done before starting the application of Weberwall finecoat.
Very smooth surfaces can hamper the adhesion strength of Weberwall finecoat. Such surfaces must be scrapped to bring it to proper roughness using emery stone/ paper.
During grinding near to areas of skirting and floor, the generated slurry can stick to the wall and spoil the finish of applied weberwall finecoat. If not cleaned properly, the upcoming layer of weberwall finecoat won’t be able to provide excellent results. There will be chances of poor adhesion resulting in problems like flaking etc. To avoid the same, skirting area up to 1 foot above ground shall be thoroughly cleaned with a wire brush and washed with water. One need to ensure to remove all slurry deposited on the wall.
Plastered surfaces showing sign of efflorescence must be taken seriously and should be treated in advance before starting the application of weberwall finecoat. efflorescence creates a barrier between adhesion of weberwall finecoat and plastered surface and in future flaking can begin. Plastered surfaces showing sign of efflorescence should be treated with citric acid (mild) or any other similar mild acid under proper supervision. After half an hour, wash the surface thoroughly to remove remaining acid content on the wall. Once the surface is in a saturated condition, application of weberwall finecoat can be started. efflorescence generally occurs due to salt or salty water in bricks/ sand.