How to repair a concrete water tank

How to repair a concrete water tank

If you have a concrete water tank with leakage, you may wonder if it can be repaired and how to proceed. Or you’re looking for some tips on how to reseal it.

Whatever the case, I’ll provide a detailed answer addressing all your concerns. Fortunately, the good news is that there are ways to fix a leaking cement water tank, although the extent of the damage will determine the course of action you need to take.

This site has an article about concrete water tanks and how long they last. The promised age that many precast cisterns have is 20-30 years.

If you own a concrete water tank, it’s essential to know how to maintain and repair it properly to ensure it functions efficiently for a long time.

Some concrete water tanks come with a warranty period of up to 20 years, making it essential to understand what the warranty covers before attempting DIY repairs.

If your water tank is relatively new, it’s better to check the warranty coverage before attempting any repairs.

However, if you have made the water tank yourself or it doesn’t come with a warranty, it’s essential to know how to fix common issues.

Repairing a concrete water tank is similar to fixing any other concrete damage.

Still, it’s crucial to remember its purpose and ensure the repair is strong enough to withstand the water pressure. If you have a leaking concrete water tank, there are ways to fix it effectively without replacing the entire tank.

How to repair a leaking concrete water tank

How to fix leaking concrete water tank

When repairing a concrete water storage tank, following a step-by-step process is essential to ensure safety and success. Here’s a more detailed breakdown of the steps involved:

Step 1: The first step is to drain the tank of water. This will allow you to access the damaged areas and make repairs.

Step 2: Depending on the tank type, it may be necessary to introduce some air flow to prevent the buildup of CO2, which can be dangerous. It’s essential to have someone else with you while working on the tank and to have a plan in an emergency. Consider using a tool to measure air quality and detect dangerous levels.

Step 3: You must order a safe liner if the tank is used for drinkable water. Measure the tank carefully to ensure that you order the correct size. While this step may seem an annoyance, it can extend your tank’s life and prevent further damage.

Step 4: Once you have your liner, it’s time to begin repairing the concrete. Start using a chisel and hammer to remove loose or damaged concrete from the crack. If the concrete is soft around the crack, remove it as well. If you notice additional cracks, use an angle grinder to cut them out in a dovetail pattern. This will provide a larger surface area for the patch to adhere to.

Step 5: After cleaning away debris, use a pressure washer to clean the area you’ll be repairing thoroughly. This will help the patch material adhere properly.

Step 6: Apply a concrete bonding agent to the cracks if recommended by local experts. Mix hydraulic cement with water according to the manufacturer’s instructions and apply it to the crack using a trowel. If hydraulic cement is unavailable, consult local hardware stores for other options.

Step 7: Once the patch has dried, clean the tank again to prepare for the liner installation. Be sure to follow the manufacturer’s instructions for installation, as the process may vary depending on the type of liner you’ve ordered.

Step 8: Installing the liner may involve using an adhesive product, which can be messy. Follow the manufacturer’s instructions carefully to avoid mistakes. Consider working on one half of the tank at a time, placing the liner in place and applying adhesive to one half, then pressing the liner into place and repeating the process on the other half.

Step 9: After the adhesive has dried, you can attend to any other attaching measures necessary for the liner. With that, your concrete water tank repair is complete.


  1. Drain the tank of water before beginning the repair process.
  2. Ensure proper ventilation to prevent buildup of CO2.
  3. Use a liner that is safe for drinkable water, if necessary.
  4. Remove any loose or damaged concrete from the crack and use an angle grinder to cut out additional cracks in a dovetail pattern.
  5. Thoroughly clean the area before applying the patch material.
  6. Apply a concrete bonding agent before applying the hydraulic cement.
  7. Follow the manufacturer’s instructions carefully while installing the liner.
  8. Use an adhesive product to attach the liner, if necessary.
  9. Allow the adhesive to dry completely before using the tank again.

Waterproof coating for concrete water tanks

If you’re looking for a comprehensive guide to waterproofing your concrete water tanks, you’ve come to the right place. In this article, we’ll walk you through everything you need to know about using waterproof coatings as an alternative to liners.

First, it’s essential to understand that waterproof coatings can offer several advantages over liners. For example, they can be more durable and long-lasting as they adhere directly to the concrete surface and are less prone to damage from external factors like UV rays or temperature fluctuations.

However, applying a waterproof coating requires careful preparation of the concrete surface. This typically involves a multi-step process that includes sandblasting, grinding, and pressure washing to remove any debris, contaminants, or loose particles that could interfere with the adhesion of the coating.

Once the surface is prepared correctly, you’ll need to choose the right type of coating for your specific needs. Several options are available, including epoxy, polyurethane, and cementitious coatings, each with unique properties and application requirements.

For example, epoxy coatings are known for their high chemical resistance and durability, making them a popular choice for industrial applications. Polyurethane coatings, on the other hand, are more flexible and can be applied in a broader range of temperatures and conditions.

When it comes to applying the coating, different methods are available depending on the product and the tank size. Some coatings can be applied using a paint roller, while others require a sprayer or specialized equipment.

It’s essential to follow the manufacturer’s instructions carefully when applying the coating, as this will ensure that you achieve the best possible results and maximize the lifespan of your water tank.

Waterproof coatings can be an excellent choice for protecting your concrete water tanks from moisture and other environmental factors. By following these guidelines and choosing the right product for your needs, you can ensure that your tank remains safe, secure, and leak-free for years.

Key points:

  1. Waterproof coatings can be a durable and long-lasting alternative to liners for concrete water tanks.
  2. The concrete surface must be adequately prepared before applying the coating, which involves a multi-step process to remove debris and contaminants.
  3. Several types of coatings are available, each with unique properties and application requirements.
  4. Different methods may be used to apply the coating, depending on the product and the tank size.
  5. It’s essential to follow the manufacturer’s instructions carefully when applying the coating to achieve the best results and maximize the lifespan of the water tank.


Using liners to repair a concrete water tank that is beginning to leak can be an excellent solution for addressing the issue.

However, before proceeding with this method, it’s advisable to compare the cost of a new water tank. The age and extent of damage to the current water tank should be considered in making this comparison.

If the concrete is starting to feel its age and is getting soft, and the rusting rebar is making some concrete spalling, it might be a better option.

If the concrete is not old and in good shape, repairing it is a valid option. Things like this are better to be done early rather than later.

The more the crack is affected by water, the more you must repair it. The more you need to repair it, the weaker the surroundings are.

Early intervention is always the best way to prevent damage. It will also always be cheaper.