Building the cast iron case for plastic rainwater systems

When it comes to the specification of building products, striking the right balance between cost effectiveness and aesthetic appeal has never been easy. In plumbing and drainage systems, cast-iron has been an integral element of the architectural landscape for over 150 years. However, as real cast iron is expensive and time consuming to work with, Hayley Lowry of Brett Martin Plumbing and Drainage explains how an efficient and economical alternative is fast becoming the main requirement for both contractors and their clients

By meeting the growing industry need for cost effective, high quality products that deliver proven performance in the long term, there is now a cast iron case for high performance rainwater systems made from plastic. Offering affordability, ease of installation, durability and low maintenance, these rainwater systems meet customer demands for heritage aesthetics but without the associated hassle or cost.

Cast iron aesthetic

Manufactured with modern plastic materials, these new and innovative rainwater systems offer a traditional appearance without a cast-iron price tag. And at a fraction of the price to buy, install and maintain, they can replace an aluminium or cast iron rainwater specification to deliver projects under budget and ahead of schedule – exceeding both the builder’s and the client’s expectations.

Heritage style gutter and pipework systems are incredibly appealing – with a highly distinctive appearance due to the texture of the material, its thickness, and the quality of each component – but the cost of traditional materials can impact heavily on a project’s budget. With plastic rainwater systems it is possible to create a heritage aesthetic without compromising architectural integrity and enjoy the savings in materials, labour and time saved on site which can actually help keep a project on budget.

Cast iron drainage systems can be heavy and difficult to install. With significant additional weight, contractors must also be extra vigilant regarding health and safety and will require more time to lift and fix the system – leading to increased costs and potential delays in the installation process. Almost every job will require both gutter and pipe lengths to be cut on-site using specialist tools and, to ensure long-lasting durability, they need to be fully finished on site, using a primer, undercoat and topcoat, to ward off corrosion. Even if the system used is delivered pre-painted, any cut lengths, or site damage to the finished surface, must be protected to the same level, by the installer. It should be noted that, in some cases, if the level of protection applied on site is deemed insufficient, any guarantee offered may be, quite rightly, invalidated, leaving the installer liable.

Because the plastic ranges are so much lighter than cast iron, installation at height is less hazardous, being effortless to lift, easy to manoeuvre, simple to cut and quick to fit. The systems also benefit from external fixing lugs, enabling easy power tool access, which further speeds up installation. All gutter fitting joints have integral seals and flexible retaining clips, allowing the gutter lengths to simply click into place. No extra-cost fixing kits or nuts and bolts are required to make gutter joints, as with most traditional systems.


To ensure each rainwater system can be designed to meet every client’s demands, there are an expansive choice of options and gutter profiles available for domestic builds and refurbishments to suit most requirements. From domestic styles of gutter to high capacity systems for larger scale commercial projects, plastic rainwater systems are also compatible with existing cast iron systems and have been carefully designed to replicate original features, dimensions and detailing.

Once installed, the system is low maintenance as, unlike cast iron, it is not vulnerable to rusting or corrosion and does not require regular sanding, priming or repainting to protect it from the elements.

Proven service

Leading suppliers and manufacturers do not just design systems to deliver optimum durability and safety standards – they provide superior technical support, detailed installation instructions and maintenance guidelines to ensure rainwater systems perform exactly as promised. Renowned for offering proven quality, these rainwater systems have been designed to facilitate fast, efficient, economical installation and exceptional reliability which provide the builder, installer and the end user with satisfaction, peace of mind and a full comprehensive guarantee.

When a traditional aesthetic is a prerequisite, the right drainage system can be the difference between design success and failure. As budgets are increasingly stretched and tight deadlines dictate product specification, housebuilders must be aware of every product’s cost – in both materials and labour. With a price tag in line with modern construction, and an appearance that blends the past with the present, a plastic rain-water system fits the bill.