Waterproofing a Concrete Tank
Waterproofing a Concrete Tank with Cementitious
Tank lining is essential in concrete water tanks as they can be subject to erosion and deterioration causing them to leak. Here at Techright, we can help!
We have the solution you need to waterproof your concrete water retaining structure with cementitious cement-based coating and give it the protection it needs.
Advantages of Cementitious:-
- Probably the easiest waterproofing materials to use.
- Cementitious is designed for internal and external water retaining structures.
- Chemical resistant.
- Excellent bonding capability.
- Cementitious waterproofing provides a seamless coating system.
- Abrasion and weather resistant.
Without a doubt, concrete tanks are undoubtedly very strong, and it is this material that causes them to be extremely heavy. As a result, it makes it a nightmare to transport, install, or carry out post-repair work.
Therefore, waterproofing concrete structures is essential to ensure a long and effective working life.
Why is your concrete tank leaking?
The first step to remediation is determining why the tank is deteriorating and leaking in the first place.
The source of a leaking tank can be caused by many factors:
- Unstable foundation
- Ground movements
- Breaking down of the concrete over time
- Tree roots penetration of the tank creating leaks
- Chemical attack
- Abrasion
- Freeze/thaw cycling
- Wet/dry cycling
The waterproofing layer must:
- Be strongly bonded to the walls
- Be effective in terms of having no leaks
- Have sufficient elasticity to withstand the pressure of water
The team at Techright must consider all the above when choosing the suitable tank lining to ensure strength and longevity of the tank.

Waterproofing the Water Tank
Generally, concrete tanks are underground due to their size and structure. As a result, this limits access and adds a considerable level of difficulty due to confined space. Prior to work it is essential to carry out confined space risk assessments and checklists. Because of this, our fully trained team has the skills and equipment allowing them to remain safe while carrying out the repairs and waterproofing your concrete tank.
To demonstrate in the video, the team will waterproof this underground fire suppression tank. During inspection, the concrete walls show evidence of cracks and erosion. Most importantly, the appropriate tank lining will be cementitious coating 851 which is designed to offer the ultimate waterproofing protection and resist 10 bar water pressure. Furthermore, its ultra-low VOC content makes it ideal for use in confined space. It is also characterised by high strength and strong bonding, but also has greatly enhanced chemical resistance.
The first step will be to drain the tank and pressure wash the walls. Secondly, it is important to fill in the cracks. And in this case, the team will use Fastfill which is a rapid setting and sets in 10 mins at 20°C and offers high bond strength.
The next step of the process is to carry out a heavy stripe coat where movement is anticipated around details and over joints, large cracks, etc. Then allow it to stabilise before proceeding with the main application.
Finally, the internal surface of the walls and floor are coated in the cementitious coating 851 with brushes and floats.
So, if you are looking for a cost-effective fix for an underground concrete water retaining structure that needs repair and waterproofing. Please contact us first.