A well-constructed underground water tank made from concrete offers a reliable and long-lasting solution for storing rainwater, irrigation water, or even creating a fire reserve. However, building one requires careful planning and execution to ensure its structural integrity and watertightness. Here are some key tips to guide you through the process:
- Planning and Permits:
- Size and Location: Determine the size of your tank based on your water storage needs. Consider factors like roof catchment area for rainwater harvesting or daily water usage for irrigation. Choose a location away from your house foundation, underground utilities, and property lines.
- Permits and Inspections: Check with your local building department to see if permits are required for constructing an underground water tank. They may also have specific regulations regarding size, location, and materials.
- Excavation and Foundation:
- Excavation: Carefully excavate the pit for your tank based on the planned dimensions. Ensure proper slope stability to prevent cave-ins. Shoring may be necessary depending on soil conditions.
- Foundation Preparation: Level the bottom of the excavation and create a solid foundation using crushed stone or compacted gravel. This base helps distribute the weight of the water tank and prevents cracking.
- Building the Walls and Floor:
- Concrete Selection: Ready mix concrete is a convenient and reliable option for constructing the walls and floor of your underground water tank. It comes pre-mixed with the correct proportions of cement, sand, and aggregate, ensuring consistent strength and quality.
- Wall Construction: Use high-quality formwork to create the desired shape and size of the tank walls. Steel rebar should be incorporated within the walls to reinforce the concrete and prevent cracking under pressure. Pour the ready mix concrete in sections, ensuring proper compaction to eliminate air pockets that could weaken the structure.
- Waterproofing and Finishing Touches:
- Waterproofing Membrane: Once the concrete has cured, apply a high-quality waterproofing membrane to the interior walls and floor of the tank. This membrane creates a barrier against water leakage and protects the concrete from deterioration.
- Access Hatch and Venting: Install a secure access hatch on the top of the tank for maintenance purposes. Venting is also crucial to prevent moisture build-up and potential mold growth inside the tank.
- Backfilling and Safety Considerations:
- Backfilling: Carefully backfill the excavated area around the tank with compacted soil in layers. This provides support to the tank walls and prevents them from collapsing due to external pressure.
- Safety First: Always prioritize safety during construction. Wear proper personal protective equipment (PPE) and follow safe excavation practices. If you’re not comfortable with DIY construction, consider hiring a qualified contractor with experience building concrete underground water tanks.
By following these tips and adhering to local regulations, you can build a robust and dependable concrete underground water tank that serves your needs for years to come. Proper maintenance and regular inspections are also key components in ensuring the longevity of your underground water tank. By keeping an eye out for any signs of wear and tear, you can address any issues before they escalate into costly repairs.
