Understand the problems of wall seepage and dampness, cracks in walls due to monsoon rains and how waterproof plaster admixtures can save walls from moisture damage.During the monsoon season, building walls may be exposed to moisture, humidity and temperature fluctuations for extended periods of time. If plaster, masonry or surface preparation cannot endure these conditions, the first indications could be the presence of damp patches, stains, peeling paint or tiny cracks. Recurrent dampness may lead to degradation of the building materials and may result in costly maintenance issues.The wise thing to do, for owners, contractors and construction people, is not to merely repair the damage that is visible after each monsoon. It is to take moisture protection into account when setting up the plastering system.

Why walls are having seepage, dampness and cracks during monsoon?

There are multiple reasons why walls might be damp. Cracks, porous surfaces, and poorly or not sealed joints or waterproofing can allow rainwater to enter. If plaster is not sufficiently water resistant, it can also absorb water.

The quality of the plastering materials and how they are applied are important too. The quality or type of sand, the surface preparation, the proportions, the curing of the plaster and the bonding, may all have a detrimental effect on the performance and durability of plaster.

It can be more difficult due to temperature changes. Expansion and contraction, drying shrinkage and moisture exposure can combine to cause cracking in plaster. But it is important to differentiate these surface/Plaster related cracks from structural cracks. Appropriate professional assessment is needed for cracks resulting from settlement, structural movement or other structural defect, not just adding a waterproofing additive to it.

What is the effect of letting the wall dampness go untreated?

It is not just an aesthetic problem if there is a persistent dampness.

Water that flows into or stays in building materials can cause peeling paint, discoloration, mould/mildew growth and plaster degradation. Water that penetrates the steel reinforcement in concrete under appropriate conditions can also cause corrosion.

For this reason it is important to think about moisture management issues as a part of the building’s overall durability and not just a mere cosmetic treatment.

Why is it that it’s worth considering waterproofing the plaster mix?

The traditional way of repairing starts after the fault is seen: filling the crack, repainting the wall or coating the surface.

These methods may be appropriate in certain cases, especially in regard to existing damage. However, they are not necessarily related to the properties of the plastering mix.

A second option is to add an appropriate admixture to the cement and sand plaster assembly in the building or remodelling process. Depending on their formulation and application, cement admixtures can change the properties of cement, including the workability, strength and water resistance.

This is to be distinguished from specific claims of particular manufacturers. For BATTU, the liquid admixture is used as a comprehensive solution for plastering and protection from moisture.

A waterproof plaster admixture can help by achieving these goals:

The right admixture can provide a number of benefits in a plaster.

Enhanced adhesion and grip.Improved adhesion and grip.

A good adhesion between plaster and the surface on which it is applied is crucial, especially on vertical surfaces and ceilings. The lack of good bonding can lead to debonding, falling material and inconsistent finish.

According to BATTU product information, the adhesive strength has improved by 95% according to a pull-out test. No product information is available to indicate the test standard or conditions, so this is a manufacturer reported result and should not be considered a universally valid result.

Rebound is reduced and material is saved.

This waste of material and effort is because of falling of plaster onto the surface during application.

BATTU claims its plastering solution minimises the rebound and optimises the use of the plaster mix, which it equates with optimal labour efficiency.

It offers greater resistance to moisture.It has enhanced moisture resistance.

The underlying principle of plastering waterproofing is to minimize the chances of water getting through the plaster to the wall.

BATTU claims its waterproof plaster would reduce water seepage and moisture issues like stain and mould. It is also reported to have an 18% increase in water-resistance on its cement-admixture page. The product material presented, however, does not identify the test standard or conditions used to obtain the 18%, so it should be interpreted as a manufacturer-claimed performance figure, rather than a general performance level.

Supporting Crack-Control Measures

Some of the conditions that contribute to plaster cracking can be mitigated by reducing moisture deterioration and enhancing the performance of the plaster. Admixtures for waterproofing should not be used as a cure-all for structural cracking, however.

Where cracks are large, persistent or pervasive, the cause of the problem should be examined before attempting to repair the plaster or to waterproof.

In some applications, BATTU says it can eliminate the need for further chemical treatments of plaster cracks such as chicken mesh on the inside surfaces. This should be taken as a statement about the product and not as a blanket statement that chicken mesh is not needed for all plastering applications.

There are several things to consider when it comes to waterproofing plaster, and before you start any work, you should definitely consider them all.

Not all construction defects can be rectified by a good admixture. Prior to plastering, the following should be taken into account:

The performance of the mortar can be influenced by the quality of the sand, including its characteristics and cleanliness.

Any dust, loose particles, grease or other contaminants on the surface can disrupt adhesion.

Mix proportions: The proportions of cement, sand, water and admixture should be used based on the application requirements and the manufacturer’s instructions.

Water management – on roof and balcony, on plumbing points, on joints and drainage should be examined for sources of water ingress.

Existing cracks: Identify if cracks are just superficial cracks in the plaster or signs of structural issues.

Andrew, follow the proper curing process of plaster and product used.

BATTU claims its product can be used in conjunction with river sand, crushed sand, OPC and PCC and can be used with hand or machine mixing. These are manufacturer’s compatibility statements and must be considered based on project requirements and application directions.

BATTU Waterproof Plaster Solution

BATTU describes its product as a liquid cement admixture comprising of natural bio-polymers and agricultural waste. The company touts it as an admixture that is added during the plastering process and not just a treatment to be applied after the wall is plastered when plastering.

Its waterproof-plaster solution is positioned around several practical site requirements, including adhesion, reduced rebound, moisture resistance and addressing challenges associated with different sand qualities. The company also states that its product can be used across different cement and sand combinations and with both hand and machine mixing.

For contractors, this integrated approach can be considered when the objective is to improve plaster performance during construction or renovation rather than repeatedly responding to dampness after the monsoon has exposed the problem.

Users should follow the manufacturer’s recommended dosage, mixing procedure and application guidance for the specific project.

Protect Walls Before the Monsoon Tests Them

Monsoon waterproofing should not begin only after damp patches appear.

Wall preparation, suitable plaster materials, proper application, appropriate curing and effective moisture management all contribute to a building’s long-term performance. A waterproof plaster admixture can form one part of that preventive approach by modifying the properties of the cement-based plaster.

For projects where seepage, dampness and plaster deterioration are recurring concerns, an integrated solution such as BATTU can be considered alongside proper construction practices.