25-Year Fire Sprinkler Inspections

If your building's sprinkler system is approaching or has passed 25 years in service, additional inspection and testing may be required. Here, we explain the 25-year assessment process, what has changed under LPC Technical Bulletin 203 (TB203) and what building owners should consider when managing an ageing sprinkler system.

What Building Owners Need to Know About 25-Year Sprinkler Inspections

A properly maintained sprinkler system can operate quietly in the background for decades without ever needing to activate. However, like any building service, sprinkler systems have milestone maintenance requirements. Just because a system has been in service for more than 25 years without obvious problems does not necessarily mean it will perform as intended when a fire occurs.

Sprinkler systems age. Pipework can corrode internally, sediment can accumulate over time and sprinkler heads can be affected by environmental conditions that are not always visible during routine inspections. This is why assessing the condition of older installations is an important part of their long-term management.

Routine servicing is essential, but it only tells part of the story. Weekly inspections, quarterly visits and annual maintenance confirm that valves are open, alarms operate correctly and key system components remain serviceable. What these activities do not always reveal is what is happening inside the pipework or whether sprinkler heads that have been installed for decades will still operate as intended. As sprinkler systems age, greater consideration needs to be given to their actual condition, looking beyond the maintenance history and examining components that would not normally be investigated during routine servicing.

The 25-Year Assessment Requirement

Once sprinklers have been in service for 25 years, BS EN 12845 requires them to be assessed. The LPC Rules and TB203 set out the detailed approach used to select and test sprinkler samples.

Recent changes to LPC Technical Bulletin 203 have renewed the focus on ageing sprinkler systems and how they are assessed. If your building has a sprinkler system approaching or exceeding 25 years of service, it is important to understand what these requirements mean and what actions may need to be planned.

What Does a 25-Year Assessment Involve?

A detailed assessment typically focuses on two key areas: the condition of the sprinkler pipework and the condition and performance of the sprinkler heads. Unlike routine servicing, these inspections are intrusive and involve removing components from the system for examination and testing.

Pipework Inspections

The sprinkler pipework is flushed and selected sections are removed for inspection. The aim is to identify issues that could affect long-term system performance, including internal and external corrosion, sediment accumulation, foreign bodies, microbiologically influenced corrosion (MIC), pinhole leaks and other signs of deterioration.

In some cases, pipework may be found to be in excellent condition despite decades of service. In others, corrosion or deposits may be discovered within systems that appear perfectly acceptable externally.

Understanding what is happening inside the pipework gives building owners better information on which to base decisions about maintenance, repairs and future replacement planning.

Sprinkler Head Testing

The second part of the assessment involves removing sprinkler heads from different locations throughout the building and sending them to an accredited laboratory for testing. The purpose is to confirm that the sprinklers still activate correctly and at the temperature at which they were designed to operate. Testing typically includes visual examination, functional testing, temperature testing and additional performance assessments where required.

Importantly, sprinklers should be sampled from different environments throughout the building. A sprinkler installed in a clean office area may experience very different conditions from one installed in a ceiling void, warehouse or loading bay. Over time, these environmental differences can influence how sprinkler heads age and perform.

What Changed Under LPC Technical Bulletin 203?

One of the main changes is that the sample now needs to better reflect where the sprinklers are installed and the level of risk within the premises. This means separate samples may be required for different sprinkler types and environments, rather than selecting a single sample based mainly on the total number of sprinklers within the building.

Under the revised guidance, the minimum is generally 10 of each type from each environment for Light and Ordinary Hazard premises, increasing to 50 for High Hazard premises. Different environments might include ceiling voids, production areas, plant spaces, loading areas or warehouse storage zones.

The rationale is straightforward: sprinklers operating in different environments may age differently, even within the same building. The revised sampling approach is intended to improve confidence that the test results are representative of the installation.

The December 2024 update is not simply about sample numbers. The way those samples are assessed has also changed. Under the revised guidance, 70% of the sprinkler sample undergoes functional testing and 30% undergoes temperature testing, with the temperature-tested proportion increasing from 20% to 30%.

What Happens If Testing Identifies Problems?

Not every inspection uncovers significant issues, and in many cases testing confirms that a sprinkler system remains in good condition.

Where problems are identified, further investigation, testing or targeted remedial works may be required to determine whether the issue is isolated or more widespread. An adverse result does not necessarily mean the entire system requires replacement, but it provides building owners with the evidence needed to plan appropriate repairs or replacement before system reliability is compromised.

Importantly, a failed test does not necessarily indicate poor maintenance. Many age-related issues can only be identified through detailed inspection and laboratory testing. From a risk management perspective, discovering these issues during a planned assessment provides an opportunity to investigate and address them before the system is called upon to operate during a fire.

The scope of a 25-year assessment will vary depending on factors such as the size and complexity of the installation, the number of different sprinkler types and environments present and the extent of any subsequent investigation required.

What Should Building Owners Do?

If your sprinkler system is approaching 25 years in service:

• Establish the age of the installation and identify any significant alterations or extensions
• Review available maintenance and inspection records
• Confirm the standards and maintenance regime applicable to the installation
• Discuss the assessment with your sprinkler maintenance provider, including required sampling and testing
• Plan ahead for any intrusive inspection, laboratory testing or remedial work that may be required

Sprinkler systems often play an important role in property protection, business continuity and insurance strategy. As sprinkler systems age, understanding their condition becomes increasingly important. Proactive inspection and remedial work also allow building owners to plan in a controlled manner rather than reacting to unexpected findings.

There is also a wider compliance consideration. Article 17 of the Regulatory Reform (Fire Safety) Order 2005 requires relevant fire safety equipment to be maintained in an efficient state, in efficient working order and in good repair. For an older sprinkler system, inspection and test results can provide important evidence of its actual condition.

In our experience, detailed inspections can identify issues that would not necessarily be apparent through routine servicing alone. Having a clear understanding of your sprinkler system's condition is preferable to making assumptions about an asset expected to protect people, property and business continuity when it matters most.

Contact Us

If your sprinkler system is approaching or has passed 25 years in service, our fire suppression team can help you understand what is required and plan the next steps. We can review available records, establish the appropriate inspection scope, interpret test results and provide independent advice on any repairs, upgrades or replacement works that may be required.