The race to get next-generation infrastructure up and running ahead of rapid cycles of technological advancement often sees foundational design considerations left on the back burner. One of the most frequently underestimated in construction projects is data center weatherproofing. And when this critical element is addressed, time and again it’s with an outdated approach.

For decades, traditional detailing methods and prefabricated roof boxes have been the default option for weatherproofing vertical penetrations on data centers. They’re widely recognized, quick and easy to specify, and thought of as a safe choice simply because they’re well known.

But with facilities under mounting pressure to maintain always-on operations and leave nothing to chance, traditional off-the-shelf solutions – rather than modern, carefully engineered strategies – pose a significant risk to long-term performance.

Yet, despite the forward-thinking mindset that characterizes the data center industry, conventional weatherproofing approaches continue to be adopted without considering a more effective alternative.

For Matthew Jones, commercial director at Jones Weatherproofing, the issue isn’t a lack of intent, but a lack of awareness: “We’re a service rather than a product,” he explains. “And that means we’re often not the first thing people think of. When weatherproofing decisions come around late in the programme, people default to what they know – not necessarily what performs best.”

Out with the old

For most data center construction projects, detailing around vertical penetrations has typically followed a familiar pattern: openings in the building envelope are created for critical mechanical and engineering (M&E) services to pass through, and a combination of metal flashings and mastics are then installed to create a weathertight seal.

“Most cladding contractors use a metal flashing that’s fixed to a vertical panel on the building using a common adhesive called a mastic seal around the perimeter and the services,” adds Jones. “A lot of companies also use something called a Nicholson roof box – an off-the-shelf weatherproofing solution.”

Roof boxes – also known as dog or junction boxes – are factory-made cabinets designed to house multiple service penetrations. Available in standard sizes and specifications, they’re widely marketed as a convenient, all-in-one solution that can also accommodate unknown or future services. On paper, they offer speed and ease. But in reality, they can introduce hidden challenges.

When installed late in the construction process and under time pressure, roof boxes are often crudely fixed and weatherproofed. As a result, fixings, joints, and sealants become exposed weak points – compromising structural integrity, energy efficiency, and leaving facilities vulnerable to water ingress.

From a practical perspective, roof boxes are also inherently bulky. On data center roofs and construction sites where space is already at a premium, their oversized footprint can restrict access for other trades.

“When space is tight, adding a large container on the roof is a real negative,” says Jones. “It creates obstacles, complicates project sequencing, and reduces future flexibility if modifications are required down the line.”

Data centers are growing in size, complexity, and number, while also emerging as visible features across urban environments and established communities – meaning aesthetics also play an important role.

Roof boxes are generic by design, and as a result, they’re not intended to align with the architectural style of a specific building or its surroundings. And even when well-finished, roof boxes are rarely discreet or well-integrated.

Shifting perspectives

The appeal of off-the-shelf solutions lies predominantly in marketed convenience. It’s common for the exact requirements of building services to remain unknown in the early design phase of a construction project – and so roof boxes are often chosen to ‘future-proof’ the building with extra space pre-installed. But putting so much faith in a one-size-fits-all approach can be risky.

Increasingly around the globe, data centers are being built across diverse markets, demanding that facilities operate in varied – and often challenging – climates.

In today’s high-stakes landscape, relying on materials with known limitations is an unnecessary gamble.

Tried and tested for over four decades, Jones Weatherproofing uses a modern liquid-applied sealing system – rather than outdated mastics – that provides effective weatherproofing across a variety of use cases, architectures, and locations.

“Mastics and flashings don’t respond well to changing temperatures,” says Jones. “There’s a real risk of breakdown over time. We know our product works across a wide range of climates – from extreme heat to severe cold.”

Bespoke liquid-applied systems are formed directly around the services they protect. There are no bulky housings or unnecessary projections – just a seamless solution that works with the building rather than against it.

However, as Jones eluded from the outset, there’s a lingering issue of perception around these systems – particularly those incorporating glass reinforced plastic (GRP) or fiberglass components.

“There’s often a taboo around the terms fiberglass and GRP,” he explains. “People instantly think these materials are brittle, breakable, and unattractive – like the leaky porch you’ve seen down the street. What we’re trying to do is educate the industry. Applied correctly and in the right situations, our system is far superior in terms of durability, versatility, and longevity.”

A false economy

When comparing standard off-the-shelf solutions with modern, tailor-made systems, the former are often assumed to be the most cost-effective option. But when the full picture is considered, this assumption can be misguided.

“Cost-wise, Nicholson roof boxes are by no means a cheap option,” says Jones. “They’re available in a set selection of sizes and specifications, built up like bulky blocks on-site, and rely on fixings, flashings, and mastics. Their performance is entirely tied to those fixings being installed perfectly.”

Once procurement, transport, installation, and remedial works are factored in, the overall cost of a roof box solution is often comparable to a bespoke liquid-applied system. The critical difference lies in lifespan.

Most roof boxes come with a standard five-year warranty. By contrast, Jones Weatherproofing offers a 25-year warranty – an assurance that remains virtually unheard of across the industry.

“That warranty speaks volumes,” says Jones. “It reflects the confidence we have in our solution and the peace of mind we’re able to give our customers.”

Traditional mastics, even high-performance variants, degrade over time due to UV exposure and even moderate seasonal temperature changes. Flashings manufactured off-site may not fit perfectly if these openings shift or tolerances vary – leading to waste and compromised seals.

Ultimately, what initially appears to be a cost-effective and convenient solution can quickly become a liability that swallows up the perceived time and cost savings just a handful of years down the line.

Structural integrity and energy efficiency

Thermal performance is another area where off-the-shelf solutions fall short. Although roof boxes are insulated, they can present a weak point in the building envelope for facilities looking to achieve low roof U-values and maximize energy efficiency. The larger the cabinet, the larger the penetration – and the greater the thermal bridge.

“If they’re not installed exactly to manufacturer specifications – and they often aren’t – then weatherproofing, airtightness, and energy efficiency are all compromised,” says Jones.

Adopting best practices, such as waste heat reuse, and working towards increasingly stringent sustainability targets begins outside the facility, by prioritizing the thermal efficiency and structural performance of the building itself.

“Thanks to our bespoke approach, we can meet virtually any U-value and provide whatever insulation depth is required – up to 200 or 250mm – and because we seal directly around the services, there are no cold bridges or thermal gaps,” continues Jones.

By sealing directly to pipes, ducts, and cable trays, the system allows insulation to pass seamlessly over the top. Because the primary weatherproofing layer sits further up the penetration, even if the building insulation degrades over time, water can’t track back into the building.

“That’s a fundamental difference,” says Jones. “With traditional flashings, the seal is only as good as the insulation beneath it, leaving significant room for error.”

Flexibility is key

Perhaps the most important advantage of a bespoke liquid-applied solution is adaptability.

Modern data centers are rarely stagnant. Services change, expand, and evolve throughout construction and operation. Once installed, roof boxes offer little flexibility. Any change can require costly alterations or the addition of extra bulk.

“With the complex vertical penetrations that characterize modern facilities, you might have multiple cable trays passing through a single opening,” says Jones. “Our system allows us to deal with that complexity on site. With flashings and mastics, it becomes incredibly difficult – and people often end up building oversized containers to compensate.”

Because fabrication and application are carried out on site, Jones Weatherproofing can respond swiftly and seamlessly to late-stage changes.

“If the M&E contractor alters a duct route or adds a cable tray at the last minute, we can deal with it,” explains Jones. “We’re manufacturing and weatherproofing on site, so we’re not locked into a fixed approach.”

Early involvement with a weatherproofing specialist enhances this flexibility even further – allowing works to be aligned with the wider construction programme and reducing the risk of delays.

Built on experience

Jones Weatherproofing has been deploying its liquid-applied systems since 1979. While the company continues to refine and improve its approach, the fundamentals remain unchanged – because they’re proven to work.

“We know our solution is tried and tested for the long run,” says Jones. “The real bottleneck is education – helping the industry understand best practice and where these systems deliver the most value.”

While off-the-shelf roof boxes may offer familiarity, this shouldn’t be mistaken for suitability. As data centers continue to scale in size, complexity, and importance, the limitations of traditional weatherproofing solutions become increasingly hard – and hazardous – to overlook.

When it comes to safeguarding data centers against the elements, the most obvious solution isn’t always the strongest. Instead, weathering the storm often means assessing the bigger picture and adopting a more forward-thinking approach.

To discuss how Jones Weatherproofing can support your next data center project, get in touch here