Why should MLCP be the default piping material of choice?
Why should MLCP be the default piping material of choice?
Copper has long been the default material of choice for pipework despite its accepted drawbacks. But that situation is no longer good enough. As construction pushes toward smarter, higher performing buildings, it is time to challenge convention and consider alternative materials that can deliver the same, if not better results with enhanced economics, sustainability and long-life durability.
Multi-Layer Composite Pipe (MLCP) is one such viable alternative. The ease with which MLCP can be installed has led to its specification on an increasing number of projects, particularly high-rise developments. This ease of installation, combined with its flexibility means MLCP helps to reduce install times, mitigate hygiene risks and provide corrosion resistance.
Dave Lancaster, Regional Product Manager at GF, explores the challenges multi-occupancy buildings can pose when it comes to choosing the right piping solutions. He outlines the importance of choosing the right partner and why MLCP should be considered as a viable alternative to copper:
“Specifiers, designers, and installers must address several challenges to ensure the efficient distribution of safe, hygienic water across all buildings, but especially in multi-occupancy buildings.
“Firstly, systems must be designed carefully to ensure user comfort with regards to water pressure – neither too much nor too little. The selection of the correct pipe size is imperative to maintain pressure and flow, as well as minimise the amount of water in the system to reduce the chance of stagnation and heat gain or loss. For example, less water means a higher exchange of water within the system.
Secondly, long-term performance must be considered. With copper piping, corrosion and limescale can develop over time, creating degraded or unstable pipes.
Thirdly, hygiene and compliance with water quality standards are imperative, as is the sustainability of pipework used. Sustainability can be evaluated by using EPDs, which manufacturers should make available to consultants to enable them to select the system with the lowest environmental impact.
“Firstly, systems must be designed carefully to ensure user comfort with regards to water pressure – neither too much nor too little. The selection of the correct pipe size is imperative to maintain pressure and flow, as well as minimise the amount of water in the system to reduce the chance of stagnation and heat gain or loss. For example, less water means a higher exchange of water within the system.
Secondly, long-term performance must be considered. With copper piping, corrosion and limescale can develop over time, creating degraded or unstable pipes.
Thirdly, hygiene and compliance with water quality standards are imperative, as is the sustainability of pipework used. Sustainability can be evaluated by using EPDs, which manufacturers should make available to consultants to enable them to select the system with the lowest environmental impact.
Material performance
“Whilst design and installation are central to building a successful piping solution, the product – and the material from which it is made – will also have a significant impact. Looking at material performance, corrosion risk, installation processes and safety and time on site, we will consider the properties of both copper and MLCP.”
“Heating and potable water systems, especially within multi-occupancy buildings, are placed under demanding pressures, often with complex pipe arrangements. As such, any chosen material needs to be strong and have mechanical robustness. To achieve this, maintaining strict control over material quality and manufacturing tolerances is essential to provide a product that offers consistent performance and durability. For example, copper tubes for domestic water and heating services should be manufactured to BS EN 1057, a specification that covers wall thickness and delivery conditions for the tubes.
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“According to BS EN 1057, the manufacturing process for copper tubes can permit relatively high tolerances – up to +/- 15% on the wall thickness. This tolerance should be applied to accommodate the varying concentricity around the wall thickness of the pipe. However, this tolerance often enables the production of thinner pipes that still comply with the published standards. Whilst compliant, these wider tolerances have the potential to increase the risk of performance issues during installation, or once systems are installed and in operation.
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“To put this into perspective, a structural steel beam manufactured at the lower end of an allowable thickness tolerance may still comply with design specification and safely support the required load. However, it has less material reserve available to accommodate wear, corrosion, or unexpected
stresses throughout its life. In the same way, a copper pipe produced towards the minimum permitted wall thickness may remain compliant, the reduced material can increase the potential for performance issues.”
Corrosion
“As with any system that carries water, corrosion is a real risk, causing system damage, lower system performance and contamination of water.
“While copper is a resilient material, corrosion can still have a negative impact on its performance. Over time, corrosion can lead to the formation of pinhole leaks, potentially compromising system integrity. Corrosion can also result in ‘blue water’, a form of discolouration that leaves blue, green deposits within the pipes and on fixtures. This issue is often linked to installation practices, such as the excessive use of flux, or when water is left stagnant in newly installed systems before they are in regular use.
“In terms of contamination, newly installed copper can have a positive impact on bacteria within a system as copper ions can break down the cell walls of bacteria such as Legionella. However, this anti-microbial effect does not continue once an oxidised layer forms on the inside of the pipe. In addition, many popular copper connections can present significant crevices which are the perfect environment for the Legionella bacteria to grow and form colonies within the system. The formation of limescale within pipe systems is also of concern when trying to maintain a healthy system. The porous nature of limescale is a perfect nursey for legionella and other bacteria to populate and colonise.
“The 300 to 600 Legionella cases reported each year** are usually attributed to poor design, operation and maintenance.
The control of hot water temperature, storage and distribution is crucial in the control of Legionella, but it is also critical that systems are correctly designed, installed appropriately and the most suitable product is selected.
“In comparison, MLCP pipes do not experience corrosion due to only having a layer of hygienic Polyethylene in contact with drinking water. The extremely smooth surface of this layer also prevents the accumulation of limescale, further protecting the health of the water, and maintaining system performance. Some manufacturers offer innovative press fittings that are designed to be crevice free to ensure that there are no areas for opportunistic bacteria to accumulate and grow. MLCP is also capped at the point of manufacture preventing contamination during transport and installation.
“In addition to corrosion and contamination, the choice of material will also play a role in the installation process, directly influencing both the speed of installation and the overall security of the system once in operation.”
Installation perfection
“According to the FCA (Financial Conduct Authority) there has been a sustained increase in ‘escape of water’ claims over the last 15 years in multi-occupancy buildings. A recent report found that ‘Association of British Insurers (ABI) statistics show that escape of water claims affecting UK commercial and industrial property insurance rose by 8 percent per year across the period from 2004 to 2021’***. This ‘water escape’ can be due to corroded pipe work, but it can also be caused by poor installation.
“Specifying a piping system that is fast, reliable and can be reviewed after installation is therefore essential. “MLCP manufacturers have developed products that help to ensure correct installation first time. When sourcing MLCP, look for manufacturers that provide three mandatory methods to check the connection is fitted properly. For example, GF’s Uponor press fitting system is protected by three essential indicators;
Finally, we always advise that the finished connection should be checked and marked as complete by the installer. This approach helps to reduce the risk of on-site errors.
“Undetected, poorly made connections with copper-based systems are an obvious cause of water loss and damage. In the worst situations, a full-bore detachment of the pipe from the fitting can spill huge amounts of water, often before the leak is detected. This situation can be particularly damaging in multi-occupancy developments where water can escape into adjoining apartments or the apartments below.
“Specifying a piping system that is fast, reliable and can be reviewed after installation is therefore essential. “MLCP manufacturers have developed products that help to ensure correct installation first time. When sourcing MLCP, look for manufacturers that provide three mandatory methods to check the connection is fitted properly. For example, GF’s Uponor press fitting system is protected by three essential indicators;
- the pipe is visible in the observation window;
- the press indicator foil has been detached;
- and the correct pressing profile can be witnessed on the pressing collar.
Finally, we always advise that the finished connection should be checked and marked as complete by the installer. This approach helps to reduce the risk of on-site errors.
“Undetected, poorly made connections with copper-based systems are an obvious cause of water loss and damage. In the worst situations, a full-bore detachment of the pipe from the fitting can spill huge amounts of water, often before the leak is detected. This situation can be particularly damaging in multi-occupancy developments where water can escape into adjoining apartments or the apartments below.
“MLCP helps reduce this risk due to its flexibility, as it can be formed to accommodate the shape of the building structure. Our Uponor piping from GF which uses a unique extruded construction to give a bending radius up to 40% tighter than that of conventional multilayer pipes. This unique feature means many changes of direction can be realised during the installation of the system, which results in fewer joints, reducing time and cost, and ensuring that pressure is maintained through to the outlet or appliance. In addition, MLCP can accommodate movement due to expansion and contraction relating to thermal movement, reducing stress on joins.
“Larger brazed copper fittings require skilled labour and will need hot works which are likely to require safety permits. This not only extends installation time and increases project costs but also introduces additional safety considerations on site.
“So how can the above be mitigated?
“The answer is for specifiers to identify products which allow them to ‘design’ risk out of a project from the outset. Whilst copper is an acceptable and common choice of material for piping systems, we would suggest considering other options – particularly MLCP – when it comes to multioccupancy buildings.”
“So how can the above be mitigated?
“The answer is for specifiers to identify products which allow them to ‘design’ risk out of a project from the outset. Whilst copper is an acceptable and common choice of material for piping systems, we would suggest considering other options – particularly MLCP – when it comes to multioccupancy buildings.”
Advanced polymers: MLCP
“Traditionally, MLCP consists of an overlapped welded aluminium pipe layered inside and out with polyethylene (in accordance with BS EN 21003). GF has manufactured a multilayer system using unique Seamless Aluminium Composite Pipe or SACP. Removing the weld seam ensures the most flexible MLCP in the market and completely removes the risk that the weld seam within the pipe could fail. The unique SACP gives highly flexible coils, and more rigid straight bars, all of which can be fixed using a longer pitch between fixings.
“However, in addition to choosing the most appropriate material and product for your project, it is critical to choose the right manufacturer.”
“However, in addition to choosing the most appropriate material and product for your project, it is critical to choose the right manufacturer.”
A perfect partnership
“Choosing a manufacturer that offers a collaborative service and on-site training - rather than one focused solely on product sales - is essential to achieving a system tailored to your specific requirements. Access to a comprehensive BIM library will further support this process, enabling you to design and plan the products efficiently into the building. With sustainability high on the agenda, it is also important to choose a supplier which places as much importance on environmental impact as you do. Environmental Product Declarations (EPDs) demonstrate a company’s dedication to sustainability and can support the creation of a more sustainable building design.
“At GF we provide a dedicated design and estimation service, working closely with clients to deliver truly fit-for-purpose solutions. This collaborative approach allows potential issues and risks to be identified and resolved at the design stage before any on-site work begins.
“We firmly believe MLCP is a strong alternative to copper. It delivers strength, reliability, ease of installation, post-installation review capability, safety and a positive installer experience. By specifying the most appropriate material - such as MLCP - at the design stage, you can help ensure that future projects are delivered on time and within budget.”
“At GF we provide a dedicated design and estimation service, working closely with clients to deliver truly fit-for-purpose solutions. This collaborative approach allows potential issues and risks to be identified and resolved at the design stage before any on-site work begins.
“We firmly believe MLCP is a strong alternative to copper. It delivers strength, reliability, ease of installation, post-installation review capability, safety and a positive installer experience. By specifying the most appropriate material - such as MLCP - at the design stage, you can help ensure that future projects are delivered on time and within budget.”