Steel water tanks over time will start to show signs of wear. Corrosion, coating breakdown and structural damage are all common issues, and when they appear, many businesses assume the only option is a full tank replacement. That is rarely the case.
In most situations, a professional steel water tank repair or tank refurbishment is far more practical.
It is quicker, more cost-effective and, when done correctly, can restore your tank to full working order for many years to come.
At COVAC, we have been completing steel tank repairs and water tank refurbishments across the UK for over 25 years.
What Causes Steel Water Tanks to Degrade?
Steel water tanks can withstand significant pressure, varying temperatures and continuous use. However, they are not immune to degradation over time.
The most common causes of deterioration in steel water tanks include:
- Corrosion and rust caused by prolonged exposure to water, humidity and condensation
- UV light and heat breaking down protective coatings on the tank interior
- Coating failure where an existing lining has cracked, peeled or reached the end of its lifespan
- Sediment build-up inside the tank, which can harbour harmful bacteria and accelerate structural damage
- Physical damage to panels or joints, particularly in pressed steel sectional water tanks and galvanised steel water tanks
Once corrosion takes hold, it provides a surface on which harmful bacteria can grow, including Legionella. This makes prompt inspection and repair not just a maintenance issue but a health and safety priority. According to HSE guidance under ACOP L8, responsible dutyholders must take action to prevent conditions that allow Legionella bacteria to proliferate in water systems.
What Are the Warning Signs That a Steel Tank Needs Repair?
There are several signs that a steel water tank may need attention.
Look out for:
- Discoloured or cloudy water coming through the system, which can indicate corrosion or bacterial growth inside the tank
- Unusual smells in the water supply
- Visible rust or staining on tank walls or panels
- Leaks or water loss around joints, seals or the tank base
- Fluctuating water pressure or temperature with no obvious external cause
- Strange noises from the tank or pipework connected to it
Any of these signs in a steel water tank should prompt a professional inspection. Many issues that appear serious on the surface can be resolved with targeted tank repair and relining rather than a full replacement. Read more about our tank refurbishment services to understand what an inspection and assessment involves.
Can a Steel Water Tank Be Repaired Instead of Replaced?
Yes. In the vast majority of cases, a steel water tank can be repaired and relined rather than replaced. This is true even for tanks with significant corrosion or physical damage such as holes.
Replacing a steel tank is expensive and disruptive. It often involves dismantling existing structures, extended downtime and significant installation costs. A professional steel tank repair service, on the other hand, can be completed on-site with minimal disruption to your operations.
At COVAC, we have completed steel tank repairs for clients across a wide range of sectors, including the NHS, hotels, universities and facilities management organisations. You can see real examples of our work in our sectional steel tanks case study and flat steel tanks case study.
What Does a Steel Water Tank Refurbishment Involve?
A professional steel water tank refurbishment follows a structured process to make sure the tank is fully cleaned, repaired and protected before it is returned to service.
Here is what the process typically looks like:
- Drain and access the tank safely, using appropriate access arrangements. For some tanks, a water tank inspection hatch may need to be installed or upgraded to allow proper entry.
- Surface preparation involving blast cleaning or mechanical preparation of the internal steel substrate. This is a critical step. Poor preparation leads to coating failure, so COVAC operatives work to European standards on surface finish before any coating is applied.
- Structural repairs to address any holes, damaged panels, corroded sections or joint failures identified during inspection.
- Application of a protective coating to the internal surfaces of the tank to create a durable, hygienic and long-lasting lining.
- Final inspection and return to service, with documentation and guarantee issued upon completion.
The full refurbishment restores the tank to a condition comparable to new, without the cost and disruption of full replacement.
What Coating Is Used to Reline a Steel Water Tank?
The coating used during steel tank relining makes a significant difference to the longevity and performance of the refurbishment. Not all coatings are equal, and for potable water tanks or any tank holding water for human use, WRAS approval and DWI listing are mandatory.
At COVAC, we use Acothane DW, our own solvent-free polyurethane protective coating system. It is specifically designed for the repair and relining of steel, concrete and GRP water storage tanks.
Key features of Acothane DW include:
- Solvent-free polyurethane formula that is safe for use in potable water tanks and drinking water tanks
- WRAS certification and DWI listing as an approved product for use in public water supply in the UK
- High impact and abrasion resistance, making it suitable for tanks in demanding environments
- Excellent elongation properties that allow the coating to flex with the tank rather than crack
- Fast return to service so your operations are not interrupted for longer than necessary
- Long-life performance with a 10-year guarantee provided by COVAC as standard
This is the same coating system we use across all types of water retaining structures, from drinking water tanks and potable water tanks to fire sprinkler tanks and hot well tanks.
How Does Tank Refurbishment Prevent Legionella Risk?
Corroded and poorly maintained steel water tanks are one of the most common sources of Legionella outbreaks in the UK. According to HSE data, when an outbreak source is identified, it is frequently linked to corroded cooling towers or poorly maintained hot and cold water systems in commercial buildings.
Corrosion inside a tank creates uneven surfaces that sediment and bacteria can cling to. This creates ideal conditions for Legionella to grow and spread through a water system. A properly relined tank eliminates this risk by creating a smooth and impermeable internal surface that resists bacterial growth.
COVAC’s Acothane DW coating system resists the growth of micro aquatic organisms and provides the peace of mind that your water system is protected. This is particularly critical for organisations with a legal duty of care, such as hospitals, hotels, schools and landlords.
How Long Does a Steel Tank Repair Last?
A professionally completed steel water tank repair and reline can last well over 20 years. COVAC backs every job with a minimum 10-year guarantee, giving clients long-term certainty on their investment.
The lifespan of the repair depends on several factors:
- The quality of surface preparation before the coating is applied
- The quality of the coating system used
- Regular inspection and maintenance after the refurbishment is complete
- The environment the tank operates in, including temperature, water chemistry and usage levels
Tanks that receive periodic inspections and are relined before serious damage occurs consistently last longer and cost less to maintain over time. COVAC can advise on appropriate inspection intervals for your specific tank type and application.
Is It More Cost-Effective to Repair or Replace a Steel Water Tank?
In almost all cases, a steel tank repair and relining is significantly more cost-effective than replacement. A full tank replacement involves the cost of the new tank itself, delivery and installation, disposal of the old tank, potential structural modifications and extended operational downtime.
A professional water tank refurbishment avoids all of that. The tank is repaired and relined in place, work is completed as quickly as possible to limit disruption and the end result is a tank that performs as if it were new.
There are situations where replacement may be necessary, such as where a tank has suffered severe structural failure across multiple panels or where it is no longer fit for its intended purpose. In those cases, COVAC will advise honestly. But for the vast majority of corroded or damaged steel water tanks, refurbishment is the smarter and more sustainable choice.
What Types of Steel Water Tanks Can COVAC Repair?
COVAC works on a wide range of steel water tanks across the UK. Our steel tank lining and repair service covers:
- Galvanised steel water tanks
- Pressed steel sectional water tanks
- Flat steel tanks
- Fire sprinkler tanks
- Hot well tanks
- Potable and drinking water storage tanks
Regardless of the size or condition of the tank, our team will assess it, advise on the most appropriate course of action and carry out the work to the highest standards. We cover the whole of the UK, with regional teams across London, the Midlands, Northern England, Southern England and Scotland.
Get a Quote for Steel Water Tank Repair
If your steel water tank is showing signs of corrosion, coating failure or damage, do not wait for the problem to get worse. A professional inspection and tank repair will almost always save money compared to leaving it until replacement is the only option.
Contact COVAC today for expert advice and a free quote or request a quote online. You can also browse our video suite to see our tank lining process in action and read client testimonials to hear what our customers say about our work.
