How-to-Guide: Cementitious Waterproofing for RCC Roof Protection

Cement is an excellent material for restricting water ingress in buildings, apartments, and other concrete-based structures. It is the prime raw material for cementitious coatings: Cement-based polymer coatings (cementitious waterproofing) are applied as a moisture barrier on roofs, walls, and floors. A high-quality cement-based waterproofing cover can last for 10 years or more. Fortify your building with sturdy RCC roof solutions. Ensure lasting durability and structural integrity.

Benefits of Cementitious Waterproof Coating

Cementitious waterproofing is a two-component mixture: Component A is a liquid, whereas Component B is a cementitious powder. It is a breathable solution that offers positive and negative side waterproofing protection. Below are some of its advantages:

• Easy to apply
• Chemical, abrasion, and weather resistant
• Effective in bonding porous and non-porous surfaces
• Exceptional freeze-thaw resistance
• Strong adhesion to well-prepared substrates

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How to Apply Cementitious Waterproofing?

Prepare the surface by removing particulates (mill scale, grease, oil, and other chemical contaminants). The surface should be bush-hammered, acid-etched, and sand-blasted. No priming is required before the application of the mixture.

Generally, cementitious waterproofing is applied in two coats. The first coat is based on proprietary materials, while the second coat is based on chemical materials combined with the cement-sand mixture. RCC roof providing reliable protection against the elements, rain or shine.

If the adhesion between the substrate and coat is improper, use an intercoat. The layering process is performed with a trowel or a spray gun. The thickness of the topping (applied above the membrane) is 2 inches. Lastly, the surface is left to dry; the curing time of 24-48 hours is set.

Applications of Cementitious Waterproofing

• Dams
• Bridges
• Railway & Subway Systems
• Tunnels
• Roofs made of concrete, cement slurries, and mosaic
• Concrete Dykes

How to Apply Cementitious Waterproofing on Rcc Roof?

1. Substrate Preparation

• Substrates should be relatively new (approx. one month).
• Surface should be free from grease, wax, dirt, and other materials.
• Use a water jet or sandblasting to remove the existing coating.
• Repair crevices and potholes before commencing the process.
• Presoak the surface with water until saturated.

2. Mixing

• Mix the liquid polymer and the powder with a slow-speed mixer.
• Mixing time should be 3-5 minutes.
• Do not pick the packets (under any condition).

3. Application

• Use a brush, trowel, or roller to apply the material: The direction should be one-way.
• Apply the first coat.
• Curing time: 3-5 hours.
• If the coat is exposed to natural elements for an extended period, wash the surface before applying another coat.
• Fiber mesh can be placed on the coat (while still wet) to cold joints, floor/wall angle connections, and crevices.
• Apply the second coat in a perpendicular direction when using a brush or roller.
• After the second coat, end the process with a trowel.
• Curing time: 4-7 days (depending on surrounding temperature and ventilation).

Please note:

• Standing water should not remain on the surface.
• Test the adhesion with the substrate.

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Cementitious Waterproofing Products – Types & Characteristics

1. Cementitious Waterproofing Slurry:A two-part mixture comprising of a cement mix and liquid polymer with additives. It is used to waterproof masonry and concrete.
2. Quick-Setting Hydraulic Cement: A quick-setting compound used to stop running water or leakage.
3. Cementitious Plugging Compound: It is a settling compound that restricts moisture intrusion in buildings. It is used as a plugging mortar, or where concrete reinforcement is required.
4. Polymer Modified Cementitious Coating: A two-component system, which on hardening, becomes an excellent water-resistant barrier. It offers resistance to positive and negative pressure (under 100m head) on roofs and decks.

What is Concrete Cancer?

When steel within a concrete structure begins to rust, concrete cancer develops. It expands and affects the surrounding concrete, causing it to become breakable.

Cementitious waterproofing is applicable on a wide variety of surfaces and locations, such as tunnels, dams, bridges, roofs, and more. If you want a cement-based coating for your premises, call up Lakhwa Chemical Services today!