Month: August 2026

What are the risks of exposed building penetrations on data centres?

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by Matthew Jones

Matthew Jones

Commercial Director

Exposed building penetrations can be problematic for any type of building, potentially causing water damage and impacting performance. For mission-critical facilities such as data centres, the consequences of exposed building penetrations can be even more significant. They can lead to equipment damage, system downtime and service disruption.

At Jones Weatherproofing, our cold-applied liquid weatherproofing can be applied quickly and to any surface, including GRP roofs. It creates a strong and durable seal around exposed building penetrations, helping to provide long-term protection to data centre buildings and the sensitive equipment that they contain.

Below are the answers to frequently asked questions about the risk of exposed building penetrations on data centres.

What are the risks of exposed penetrations?

When a building penetration is exposed, it becomes vulnerable to moisture ingress. This can lead to a range of problems, including:

  • Leaks – Water from precipitation can enter through an exposed penetration, allowing moisture, including damp or drips, into the building.
  • Condensation – Gaps in the building fabric can impact performance, allowing interstitial condensation to form within walls, roofs or floors.
  • Damp – Persistent moisture from leaks or condensation can lead to persistent damp, which can damage equipment and cause problems such as mould, mildew and rot.
  • Structural damage – Moisture within the building envelope can contribute to deterioration, including timber rot and metal corrosion.
  • Contents damage – Water ingress can damage the items inside the building. In a data centre, this could mean expensive servers and other critical technology.
  • Equipment downtime – Even small amounts of water ingress can damage sensitive equipment, resulting in costly downtime and operational disruption that can affect a data centre’s reliability and reputation.
  • Poor indoor air quality – Damp conditions can encourage the growth of mould and mildew. This can negatively affect indoor air quality for the people inside the building.
  • Impact on occupant wellbeing – Leaks, damp, mould and poor indoor air quality can create an uncomfortable environment and may contribute to health issues for occupants. They can also affect a building’s thermal performance, and damp-related structural damage can create unsafe working conditions.

How does water ingress affect building penetrations?

Exposed or damaged penetrations allow water to get inside the building envelope. Once moisture is present, it can cause deterioration, making the penetration more vulnerable to further water ingress and creating a cycle of ongoing damage.

Can building penetrations be damaged by people working on site?

Yes. Building penetrations – particularly exposed penetrations – are often damaged by people working on site. This can be during construction or as part of ongoing maintenance once the building is complete. For this reason, building penetrations should be sealed with a resilient material that can withstand accidental impact, foot traffic and general site activity.

The potential for damaged building penetrations also highlights the importance of programme sequencing during construction. When penetration weatherproofing is completed at the appropriate stage of the build programme, it minimises the risk of damage and subsequent remedial works.

How can damaged building penetrations delay a project?

When building penetrations become damaged, they need to be repaired and resealed as quickly as possible to minimise risks to the building structure and contents.

While sealing a penetration with the Jones Weatherproofing cold-applied liquid weatherproofing can be quick, gaining access to the affected area is often more complicated.

Depending on the building design, accessing a penetration may require removing adjacent installations or finishes. These will then need to be reinstalled once the penetration is sealed. This additional work can lead to programme delays and added costs.

How can exposed building penetrations lead to water damage to equipment inside a building?

An exposed building penetration can take many forms. It might be a hairline gap between a service and the surrounding building fabric, or it can be a large opening created for a service riser. While it is easy to see how moisture can enter through larger gaps, it’s important to remember that even small openings can provide a pathway for water and moisture ingress.

Once water enters the building envelope, it can travel through the construction layers and into the building interior, where it may drip onto sensitive equipment.

Even small amounts of moisture can accumulate inside building elements, damaging building materials and widening the pathway for moisture. Over time, this can increase the likelihood of leaks and water ingress, potentially leading to damage or disruption.

 

 

Why should building penetrations be protected from the earliest stages of a data centre project?

The construction of a data centre is often quick, with multiple trades working closely together. If building penetrations are left unprotected, or weatherproofing is delayed until later in the programme, the openings are more likely to be exposed to weather damage or accidental damage.

There’s also the chance that if a building penetration is left unsealed, other equipment or finishes may be installed over it. Installing the weatherproofing layer may then require items to be removed to provide access, then reinstalled, leading to delays and added labour costs.

Weatherproofing penetrations at the right time can help maintain the integrity of the building envelope throughout the build and protect it from weather ingress. It also reduces the likelihood of remedial works and helps to avoid programme delays.

What is the best way to weatherproof building penetrations on data centres?

There are many ways to seal building penetrations in data centres. Traditional systems, such as rigid or “dog-kennel” style enclosures, have been used in the past. But they can be bulky and difficult to maintain. They also limit flexibility where service layouts may change during the build.

In data centres, where service density is high and project requirements can change, a more adaptable approach to weatherproofing is often required.

At Jones Weatherproofing, we use cold-applied liquid weatherproofing based on unsaturated polyester resins. It is suitable for all roof types, including GRP, and creates a permanently resilient, UV-stable seal that provides long-term protection around building penetrations. The system is versatile – it can be adapted to suit last-minute changes to penetration configurations in new-build applications and is also suitable for sealing around penetrations in existing data centres.

How can I learn more about reducing the risk of exposed penetrations on data centres?

The team at Jones Weatherproofing has extensive experience in weatherproofing penetrations on data centres and other mission-critical buildings. To find out more about our weatherproofing system, or discuss how we can help you reduce the risk of exposed penetrations, please get in touch.

What is BROOF(t4)? A guide to roof fire classification and compliance

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by Jamie Sporcic

Jamie Sporcic

Senior sales manager

Fire safety is a critical consideration for all buildings. As regulations and specifications have tightened in recent years, so has the need to demonstrate compliance. For roofs, fire safety standards have taken several forms, including the BROOF(t4) classification.

What is BROOF(t4)?

BROOF(t4 )is a fire classification that assesses a roof’s resistance to external fire sources, including burning embers and nearby fires. It is the highest classification for UK roof performance. It indicates that a complete roofing system – the combination of deck, vapour control layer (VCL), insulation, underlay, finishes and other treatments – has passed stringent testing.

What does BROOF(t4) testing involve?

External fire performance of roofs is assessed using test methods defined in CEN/TS 1187, with results classified in accordance with BS EN 13501-5. Testing must be carried out by an accredited third-party organisation.

There are four different tests defined by CEN/TS 1187. These tests use a burning brand – a standardised burning object – as the flame source. During each test, samples are exposed to realistic fire scenarios that simulate external fire conditions, such as airborne embers or flames from adjacent structures.

  • t1: Burning brands
  • t2: Burning brands with wind
  • t3: Burning brands with wind and supplementary radiant heat
  • t4: A two-stage exposure incorporating burning brands, wind and supplementary radiant heat

Classification is based on a range of performance criteria observed during testing under defined conditions. These include flame spread, fire penetration and burn characteristics.

The t4 test is commonly used in UK guidance, with BROOF(t4) being the highest classification achievable under EN 13501-5 for the external fire performance of roofs. This indicates that the roof system has demonstrated a high level of resistance to external fire spread under the specified test conditions. C, D, E and F classifications may also be granted to a roof system. FROOF(t4) is the lowest rating and indicates that no performance was determined.

Systems must be tested as a complete build-up. Any changes to the specification will require the complete roof system to be re-tested.

Is BROOF(t4) a requirement in the UK?

BROOF(t4) is the classification most commonly referenced in UK guidance and specifications. BROOF(t1) is often used in other countries or for specific applications.

A classification of BROOF(t4) demonstrates compliance for applications where roof coverings must meet specific performance standards. It is commonly used within fire safety guidance across the UK, including Approved Document B: Fire Safety (England).

Requirement B4 of Approved Document B (Volumes 1 and 2) states that the external envelope of a building should not:

  • Contribute to undue fire spread from one part of a building to another part.
  • Provide a medium for the spread of fire to adjacent buildings.
  • Be readily ignited by fires in adjacent buildings.

For a roof system to be considered “unrestricted” in use, Approved Document B states that it must achieve the BROOF(t4) classification. This applies across most building types, particularly those where proximity to other properties or increased fire risk requires the highest level of fire performance.

Similar guidance exists for the rest of the UK, including Approved Document B: Fire Safety (Wales), the Technical Handbooks (Section 2: Fire) in Scotland and Technical Booklet E: Fire Safety (Northern Ireland).

 

Complex service riser weatherproofed in London

 

Is BROOF(t4) the same as a Euroclass or Class 0 rating?

It is a common misconception that BROOF(t4) is interchangeable with the Euroclass B rating. However, they are not the same.

  • Euroclass B is a product classification under BS EN 13501-1. It measures the reaction to fire of individual materials.
  • BROOF(t4) is required by BS EN 13501-5 and assesses the external fire resistance of a complete roof system.

As has been demonstrated in real-world fire events and full-scale testing, an individual product’s fire performance does not always reflect how a complete system will behave in a fire. The interaction of materials is a critical consideration – and that is why BROOF(t4) testing is so important.

Class 0 is an older fire classification based on testing methods in BS 476. It was used to assess surface spread of flame and fire propagation characteristics on individual building materials and was widely referenced in earlier guidance. However, it does not assess reaction to external roof fire exposure, and it has largely been superseded by other fire classification systems.

What does BROOF(t4) mean for localised weatherproofing?

As already discussed, BROOF(t4) classification applies to a complete tested roof system, rather than to individual components or localised detailing.

Penetrations, joints and interfaces, along with their weatherproofing treatments, are therefore not typically assessed during fire testing. Instead, they must perform in a way that is compatible with the overall roof build-up.

Products used for detailing, such as liquid-applied weatherproofing systems, should be selected to ensure they are compatible with the wider roof assembly and do not negatively impact its external fire performance.

One way to do this is to use products that have been used within roof assemblies that achieve BROOF(t4) classification. This provides confidence that the detailing is compatible with compliant roof systems, provided it is installed in accordance with the tested build-up and relevant application guidance.

Does the Jones Weatherproofing system have BROOF(t4) classification?

As fire performance depends on the complete roof system, including the substrate, insulation and configuration, each application must be considered individually.
Jones Weatherproofing systems have been tested as part of complete roof assemblies that have achieved BROOF(t4) classification in accordance with BS EN 13501-5:2016.

These test results demonstrate that Jones Weatherproofing systems can form part of roof assemblies achieving BROOF(t4) when installed as part of a tested configuration.
For complex environments such as data centres, where high service densities and late-stage design changes require adaptable detailing, Jones Weatherproofing can help ensure appropriate specification and integration with the wider roof system.

To discuss the fire performance of the Jones Weatherproofing system in more detail, review our test reports or learn how we can support the weatherproofing of an upcoming mission-critical projects such as data centres, please get in touch.