Weatherproofing for building penetrations is still often treated as an afterthought, with decisions left until late in the construction programme or delegated to on-site trades.
Waiting to implement a weatherproofing strategy until late in the build may be common, but it also introduces risk. Projects are more vulnerable to inconsistent installation, programme delays and costly remedial work. Poorly weatherproofed penetrations can also allow water ingress, affecting the long-term performance of the building envelope.
By specifying weatherproofing at the design stage, architects and specifiers can ensure that penetration details are coordinated with the wider project from day one. This improves communication, helps protect the design intent and reduces the likelihood of unplanned changes during construction.
The value of early weatherproofing specification
Across the construction industry, there is an increasing focus on coordinated design, accountability and clearly defined responsibilities.
The Building Safety Act 2022, for example, introduced strict safety and accountability standards for higher-risk buildings, requiring clear lines of responsibility throughout the whole life of a building. It also emphasises the importance of the “golden thread”, a secure and up-to-date digital record of a building’s design, construction and ongoing maintenance. This reinforces the importance of specifying a weatherproofing system, rather than leaving decisions to be made on site.
Whether or not a building qualifies as high-risk, the benefits of specifying weatherproofing for building penetrations early in a project are clear. Inadequate weatherproofing can compromise a building’s structural integrity, as well as the safety of occupants and building contents. It can also cause project delays and lead to the need for remedial works before a building is even fully constructed.
From mission-critical buildings such as data centres and hospitals to retail buildings, football stadiums and manufacturing facilities, good weatherproofing reduces risk and improves project outcomes.
Why weatherproofing penetrations requires clear project communication
The responsibility for weatherproofing building penetrations is often unclear. Roofing contractors, MEP installers and specialist subcontractors may all be involved in creating and installing penetrations – but who should ensure that a penetration is weatherproofed, and who will be accountable if the weatherproofing fails? This is why clear communication is essential.
Specifying a dedicated weatherproofing partner establishes a strategy and a clear point of contact. Specialist knowledge, expert advice and an experienced installation team can all help ensure that the weatherproofing is carried out to a high standard, at the right time and in a way that will support the building envelope’s long-term performance.
Specifying weatherproofing for penetrations to meet project requirements
No two projects are the same. They have different roof build-ups, different exposures and different building penetration requirements.
Considering weatherproofing during the planning stages of a project, helps architects and specifiers ensure that the chosen system is compatible with the roof construction, that there is enough space for each penetration and that there is sufficient access for weatherproofing, long-term maintenance and inspection.
Fire performance may also be an important consideration when specifying weatherproofing systems, particularly on projects where external fire exposure requirements apply. BROOF(t4) classification relates to complete roof assemblies rather than individual products. 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.
Matthew Jones, commercial director at Jones Weatherproofing, explains that working with a specialist weatherproofing contractor from the design stage also provides valuable technical expertise.
“Having someone focus specifically on weatherproofing helps ensure that all aspects are fully considered,” he says. “They can help identify potential challenges before construction begins and reduce the need for design changes later.”
Preserving the architectural vision with weatherproofing for building penetrations
When weatherproofing is left until construction is underway – or nearly complete – it can limit the options available. Compromises may be made that don’t match the original design intent, and visible alterations may be necessary to accommodate penetration details.
And if the weatherproofing is carried out by a contractor who doesn’t have specialist knowledge, they may not be aware of the methods that could help to preserve the architectural vision.
In many cases, last-minute weatherproofing consideration can lead to the use of dog-kennel-style enclosures and other ready-made systems. While these can be effective, they are often poorly installed and incorrectly sized. They can also interrupt the roof’s visual lines and negatively impact the overall building aesthetic.
“Specifying weatherproofing early allows penetration details to be integrated into the overall roof design,” Matthew explains. “This helps to ensure that the completed building reflects the architect’s original vision, while also providing reliable protection from water ingress,” he says.
Matthew also notes that early engagement does not mean every detail is locked in from the beginning. “Building penetrations often change as a project develops. Working with a specialist weatherproofing contractor makes it easier to accommodate these changes without compromising performance or the project programme,” he adds.
Preventing the use of unsuitable weatherproofing systems
If weatherproofing requirements have not been clearly specified, contractors may need to rely on standard off-the-shelf products that are not ideally suited to the project. While these products may have appropriate applications, a more bespoke weatherproofing approach typically leads to better long-term outcomes.
“Jones Weatherproofing’s cold-applied liquid weatherproofing provides a seamless, fully bonded waterproof layer that can be formed around penetrations of almost any shape or size,” Matthew explains. “Unlike some traditional methods, it can accommodate irregular details and multiple services without relying on numerous individual fittings or joints.”
Specifying an appropriate weatherproofing system helps ensure that performance requirements are maintained throughout the life of the building and reduces the risk of inferior substitute products being introduced during construction.
How specifying weatherproofing for penetrations can help avoid project delays
Construction programmes rely on careful coordination between multiple trades. If penetration weatherproofing is not properly planned, installers may need to revisit completed work, remove newly installed building elements to gain access or make last-minute design changes before weatherproofing work can begin.
“By specifying weatherproofing early in the project, installation can be planned alongside other construction activities,” Matthew explains. “Penetrations can be sealed in the correct sequence, reducing disruption to other trades and helping minimise the risk of water ingress before the building envelope is complete.”
This coordinated approach helps maintain programme certainty, reduces unnecessary rework and supports on-time project delivery.
Specifying penetration weatherproofing from Jones Weatherproofing
Jones Weatherproofing works closely with architects, specifiers, contractors and project teams to provide weatherproofing that is tailored to specific project requirements.
Wherever possible, our team is involved from the earliest stages of a project. During specification, we can provide technical advice, develop suitable weatherproofing details and help coordinate installation with the wider construction programme.
Get in touch to find out how Jones Weatherproofing can support your next project’s weatherproofing requirements.
