Waterproofing Concrete Water Tanks

 

Water reservoirs, damns, wastewater treatment plants, and drinking water facilities are vital to the public works of communities. When the concrete is in bad condition and water leaks it can mean that the structure allows contaminants out of or into the storage.  The contaminants can ruin water supplies and significantly impact communities.

Leaks & Contamination

Municipal or private water supplies can be contaminated through the migration of waterborne chemicals. When wastewater structures leak it can impact the environment and are especially hard to find if they are in the base of the concrete structure. With drought being a reality in so many areas of the world even small losses of drinking or agricultural water have a meaningful impact.  When any kind of water storage container needs extensive repair it means disruption to the community through downtime and expense.

Cracks & Service Interruption

Just about every concrete structure cracks due to settling, curing, seismic activity, shrinkage, or a number of other factors.  When it comes to concrete water tanks any cracking can lead to leaks and contamination.  These are the two most common factors of having downtime in operations that rely on concrete water holding structures, like wastewater or cooling towers.

Crack Prevention

Preventing cracks is clearly a priority for all operations that include water storage.  Preventing cracks and leaks comes in various waterproofing forms.  Here are few of the options on the market today:

• Installing a coating of liquid membrane by spraying or rolling which leaves a dry yet rubberized waterproof layer. The rubberized nature of these coatings helps the layer be flexible and compensate for cracks.
• Layered felt and asphalt which are built up into layers which creates a physical waterproof barrier.
• Membranes of self-adhering rubberized asphalt that make a barrier.
• Integral crystalline waterproofing can also be used to fill the spaces between parties of concrete.
• Cementitious waterproofing products brush applied to the concrete and can be mixed with optional additives which increase durability.
• Installing a sodium bentonite layer on the outside of the tank will absorb water and expanding to fill in the voids and cracks. When it fully expands it remains in the cracks to avoid additional water intrusion.

Choosing a Tank Waterproofing Option

There are a lot of products and companies offering water tank coating, how do you choose the best option for your system?  These are some of the factors that you should consider as you make decisions for your property and water storage or containment.

System Safety

Choose waterproofing coatings which are safe for the environment and are non-toxic.  When the project involves storing drinking water is especially important to choose a system which will not deposit chemicals or debris into the water.

Cost Of The System

How much the system will cost in terms of raw materials and labor hours should be weighed against the lifespan expected from each product.  Waterproofing coatings which take longer to apply will generally be more costly.

Time To Install

When you are dealing with a complex construction project or you are planning downtime for a system that a building or community relies on you need to know how long it will take to install.  Physical barriers like rubber and felt are time intensive and will require longer install times that could mean increased interruption in service.

Waterproofing Life Span

Knowing the expected life span of the waterproofing solution should play into your decision making.  Some products are designed to be permanent solutions while others have a finite life span.  Other systems eventually dry out, crack, are easily damaged, and will eventually leak and cause contamination.  Weight out how long the solution will last against the cost and service interruption.

System Flexibility

Does the system have a required installation time?  Some systems must be installed either before, during, or after the concrete is poured to create the structure.  Some systems mean having to keep the area around the water tank clear so maintenance can be done on the exterior of the water storage tank.

Heat Compatibility

Some water containment systems require the ability to withstand heated water such as in cooling tower water basins.  The heat involved in cooling tower applications must considered when choosing an option for concrete waterproofing.

Chemical Resistance

Many water storage systems like wastewater, drinking water, or the water used in cooling towers carries with it chemicals that can deteriorate concrete.  Coatings must be used which can cope with the chemicals used to treat these different types of water.

Warranty or Guarantee

When you are weighing your options for which concrete water tank waterproofing contractor or product to use you should weight the warranties or guarantee. It’s important to choose tank maintenance companies and products that warranty their work and products.

Conclusion

Ultimately each installation is different as the operations, environment, age, and condition of every tank is different. Take the time to discuss your options for your local contractor for waterproofing concrete water tanks.  Have representatives come and assess the condition of the your water tank, recommend the best solution or solutions, and then choose the one that fits your needs best.  What is best will depend on how long the system should last, if and how disruptive downtime is to the community.