10 Top Tips for Making Your Module Weathertight and Airtight

Ryan Gerrard / 13 June 2023

When it comes to making modules both weather and airtight, there are a number of key considerations that you must factor into your project in order to achieve optimum building performance levels.

Here at Tremco CPG UK, our vast product portfolio includes numerous solutions for offsite construction and are specifically designed to help architects and specifiers enhance the capabilities of their structures. Explore our latest blog to find out our top tips for making your module weathertight and airtight.

1. Understand your build design challenges

First and foremost, you must consider the possible challenges in relation to the design of your build. During this stage, think about the environment in which the module will be placed and how that may have an impact on its design. For example, the environment may produce high levels of moisture, or the module may be situated in an area affected by bad weather. In instances like this, a solution that combats driving rain by providing a robust weathertight seal will be required.

Another build design challenge concerns the use of external cladding and insulation. An external wall solution is ideal for improving the energy efficiency of a module, as well as improving its weathertight capabilities by preventing weather, cold air, and moisture from entering the structure. However, the subsequent requirements of other building fabric elements in the detail will also need to be taken into account. Our range of products are designed to work on the cold side of the building envelope, engineered to allow water vapour to escape from inside the building to reduce the condensation risk. CPG UK’s modular manufacturing team will help you to understand and pre-empt potential build design challenges from the offset, reducing the risk of encountering further issues down the line.

2. Understand your requirements

What are the requirements for your module? Achieving air and weathertightness around module joints is becoming ever more prevalent, to enhance the thermal retention qualities of structures whilst also reducing the impact of convection heat losses and moisture build up. These important requirements can be achieved by focusing on the materials used in both the interior and exterior of the module. For example, using a high strength membrane such as illbruck ME501 Duo Window Membrane HD, which can be applied before or after the installation of windows, provides a weathertight (against driving rain up to 1200 Pa) and airtight (to Passiv Haus levels) seal for both internal and external applications. Applied in conjunction with illbruck SP525 Frame and Façade Sealant & Adhesive, or as a self-adhesive version, this UV stable, compatible membrane is BBA accredited and complies with the principle of ‘inside tighter than outside’ to facilitate efficient vapour control.

3. Understand your building regulations

Designed to protect the health and safety of those in and around buildings, one of the most crucial aspects of any construction project is understanding the current building regulations and how they will affect the structure of your module. For instance, important changes outlined in Approved Document L became mandatory in June 2022, and are transitional steps towards The Future Homes Standard and The Future Buildings Standard. Due to be implemented in 2025, these standards aim to futureproof structures with the Government’s aim of achieving net zero by 2050. Looking towards the materials used in the fabric of the module and maximising their performance, will help you achieve adequate air and weathertightness, which in turn will optimise the module’s energy performance. An ideal system is the fully BBA approved illbruck i3 system, which strives to seal OUT the weather whilst sealing IN comfort and energy savings.

4. Get to grips with your sequence of installation

To ensure your module is both airtight and weathertight, it is important to get to grips with your sequence of installation first, as this will ultimately affect the suitability of the solutions specified for constructing the module. As modular manufacturing experts, the team at CPG will be mindful of your installation methods to help you to find the best possible solution in the most efficient manner. We will work closely with you to understand your processes, preferences, and offsite construction needs. For example, if you have a project where tolerance is controllable, or minimal onsite sealing is desirable, our impregnated tape systems can be pre-applied at factory build stage for compression or expansion during site installation. 

5. Meet our technical team

The CPG UK technical team share many years of industry experience and technical know-how between them, putting them in pole position to aid you with any technical queries you may have about our range of solutions, or the environment in which they will be installed. Offering unrivalled levels of support, our experts in sealing, bonding, and insulation solutions have over 85 years of combined experience and can provide everything from technical calculations to specification services, as well as onsite support and surveys.

6. Choosing the right products

We understand the complexities of modular construction and the challenges in finding the right solutions to meet your performance requirements. To help you choose the best products for your module’s environment, you can utilise our range of handy selector tools that are designed to make the selection process more straightforward. For weathertightness and airtightness requirements, we recommend our easy-to-use Membrane Selector, which assists architects and specifiers by outlining the variety of membranes we have to offer. The tool also advises on the most suitable options for your application and performance requisites. Simply navigate through the chart to explore the various weathertight and airtight membranes available in our portfolio. For further advice on the most appropriate solution, our technical team will be more than happy to help.

7. Let's talk training

Enrolling in the Tremco CPG UK Training Academy will help you to navigate through the sometimes challenging world of construction. Our variety of online and in-person training sessions cover a broad subject matter, hosted by our experienced and dedicated construction specialists who are well versed in the complexities of the industry, and can tailor your training requirements to ensure you receive the help and support you need. From RIBA approved CPD seminars for architects, to application tutorials for installers and contractors, as well as bite-sized ‘coffee chats’ covering the latest hot construction topics, CPG’s Training Academy caters to all.

One of our RIBA approved CPDs, A Guide to Sealing Facades, Windows & Doors, in relation to Approved Document L, explores a ‘Fabric First’ approach to construction. This process looks to increase airtightness in buildings, eliminate thermal bridging, and optimise a dwelling’s thermal performance through insulation.

8. Value engineered and improved installation processes

At the beginning of your project, our modular manufacturing team will sit down with you to discuss your processes, understand any concerns you may have, and subsequently define the most appropriate solutions for the construction of your module. Tremco CPG’s range of offsite construction solutions provide added value through technology engineering that meet the stringent requirements of today’s industry. Our compatible products work in harmony with one another, improving the overall installation process, and ensuring your module achieves the required air and weathertightness levels.

9. Re-evaluation and continuous improvement

Our solutions for modular construction have been rigorously trialled and tested throughout the years, with a view to constantly improving our product technology and provide best in class construction innovation. It is through many decades of dedication and tenacity that have resulted in third-party accreditation for numerous products in our range. Our module joint solutions, for instance, are designed and tested at our in-house facility to meet specific project and/or manufacturing requirements. Utilising a range of tapes, sealants, and waterproofing technologies, we can offer many options to allow the creation of robust junction details, along with acoustic and fire performance options. We understand the importance of compliant and reliable systems within the industry, and are always exploring the best solutions available for our customers, keeping them regularly updated with the latest innovations available on the market.

10. CPG added value

In recognition of the construction industry’s demand for more efficient construction techniques and processes, CPG UK has responded with modern methods of construction that are specifically designed for the offsite sector. Working with one point of contact for seven leading product brands, you will receive a broad spectrum of technologies to suit almost all applications. Our solutions are suitable for module joints, internal and external walls, flooring installation, park and leisure environments, as well as bathroom pods and fit outs.

As a customer of Tremco CPG UK, you will benefit from simplicity of short supply routes, products that work together from one accountable manufacturer, and construction solutions that simply work better and harder for you. For more information about how our offsite construction experts can help make your module weathertight and airtight, please get in touch today.