Silicone hydrophobic agents

The application of silicone hydrophobic agent is very wide, and its main value is reflected in the protection of porous inorganic building materials.

Building exterior and roof waterproofing: This is the most extensive application area for silicone-based hydrophobic agents. Whether for concrete walls, tile surfaces, stone cladding, or exposed brick walls, the spray application effectively addresses issues like leakage, moisture resistance, weathering, and pollution prevention. For renovation of existing structures, the process can be directly implemented without removing original finishes, offering both cost-effectiveness and efficiency.

The cement-based materials modification: by adding the cement into the dry-mixed mortar, such as plastering mortar and thermal insulation mortar, the water absorption rate of the materials can be significantly reduced, and the impermeability and durability can be improved.

The ancient architecture and the protection of cultural relics: Because of its excellent permeability and color preservation, it is especially suitable for the protection of stone tablet, brick carving, ancient architecture wall, etc. It can prevent the growth of moss, salt erosion and weathering, and keep the original appearance of cultural relics.

Special applications: also used in warehouses, archives for moisture-proof; basement, pool waterproofing; and rock wool and other inorganic insulation materials for hydrophobic treatment.

There are two main ways of application of silicone water repellent: external coating and internal mixing.

Spray construction (most commonly used):

The construction surface must be solid, flat, dry, clean, and free of oil stains, moss, or loose materials. Any cracks or holes should be repaired with specialized materials first.

Dilution ratio: usually diluted with water in a ratio of 1:5 to 1:15 as per the product instructions and stirred evenly.

Spraying operation: Use a sprayer to spray two consecutive layers in a crisscross pattern on the dry surface, with a short interval (usually within 2 hours) to ensure effective penetration of the second layer. Generally, 4-5 square meters (two layers) can be sprayed per kilogram of diluted solution.

Environmental requirements: During construction and curing, the temperature must be above 5℃, the base surface must be dry, and rainwater erosion must be avoided within 24 hours after construction. Under normal temperature, the hydrophobic effect becomes visible within 24 hours, and the optimal effect is achieved after one week.

The impregnation method: In the production of dry mortar (e.g. waterproof mortar, putty, joint filler), the hydrophobic agent powder is directly mixed into the dry material in a certain proportion (e.g. 0.2%-0.5%) of the weight of the cementitious material.

When using silicone hydrophobic agents, the following issues require special attention:

Poor or failed hydrophobic performance: The most common cause is improper substrate preparation, such as an unclean, unstable, or undried surface. Additionally, incorrect dilution ratios, insufficient spray volume, or failure to follow specified application cycles can result in incomplete film formation. Construction during rainy weather or at low temperatures (<5°C) can also significantly impair curing effectiveness.

Uneven coloration or bright spots: If the coating is applied unevenly or excessively thick in certain areas, dark patches may appear on lighter surfaces. Similarly, materials with porous or highly uneven water absorption rates can also result in color inconsistencies due to uneven absorption.

Poor adhesion with subsequent finish layers: Applying paint or tiling tiles on a surface treated with a hydrophobic agent will significantly reduce the bonding strength of the subsequent materials. Therefore, the construction sequence must be carefully planned, typically starting with other finishing works before applying the hydrophobic agent.

Material deterioration: The hydrophobic agent should be stored in a sealed container at a cool place between 0-30℃, avoiding direct sunlight and freezing. The container lid must be tightly sealed, but periodically opened for air release during long-term storage (never stored without a lid) to prevent degradation.