Everyone loves the cast iron look, but there’s only one cast iron rainwater

Posted by: julie    |   Date posted: 04/09/2017

Speaking as a market leading cast iron rainwater supplier, I suppose cast iron should be flattered by plastic guttering companies promoting a ‘cast iron’ look-a-like product range. It is, after all, the look that people love. But that’s all it is, a look, and people should be careful not to assume plastic also has cast iron’s other performance attributes or its suitability for cast iron applications.

If you’re changing your company car to a top of the range grey Audi, you don’t want to find your purchasing manager comes back with a cheaper, lighter Ford Focus – just because both are anthracite grey.

There are risks to installing low cost ‘cast iron’ effect plastic where only the strength, robustness and long-lasting looks of premium cast iron will do. The two materials are suited to very different markets, with very little overlap.

Designed for tomorrow’s climate?

Our climate is changing faster than expected and, from a product and materials perspective, that means designing and building for tomorrow’s weather, not yesterday’s. Designers have to consider how different materials behave in the warmer, wetter, windier weather that’s on its way, and the amount of UV light products and materials will be exposed to.

It often takes a shock to get us to change how we build. We got a foretaste of this in the recent hot spell when some builders were surprised by coloured plastic guttering expanding and distorting so much in the heat that it had to be replaced before the scaffolding was removed. Coloured plastic, and dark colours especially, absorb heat and expand greatly.

A product like rainwater has a lot to do. Its job is to reliably protect the building from the extremes of weather while looking great (and enhancing the look of the building) with a minimum of upkeep, trouble and cost over many decades in a changing climate. That’s a tall order given the variety of building types, sizes and ages it will be installed on, and the functions of the property and extremes of weather it protects against.

Specifiers, builders, builders’ merchants and property owners rely on specifications and robust product application advice to establish clearly the limits and suitability of the product. Sometimes people see what they want to see, and let wishful thinking push the boundaries of what is sensible. But post-Grenfell, the question of what products should be used where – not just for fire safety – have taken on a greater significance. No doubt, technical teams in all product categories across Britain are looking with great care to make sure their specifications and advice are correct.

Different materials for different markets

Reading recent articles in the trade press you could be forgiven for thinking that cast iron rainwater and cast iron effect plastic rainwater are interchangeable, that either could be substituted for the other, in any project. But that’s highly misleading. Both have a ‘cast iron’ look, but only one is cast iron, and the materials they’re made from are inherently suited to very different markets.

Plastic rainwater is lightweight and easy to install. It’s cheap, and ideal for mass-market housing. Most comes with a limited range of standard through-colours. The ‘cast-iron’ effect is applied as a thin paint coating to the plastic, and being plastic it expands in the heat and creates significant movement. Coloured guttering expands considerably more than white, causing the creaks and groans on warm nights as it expands and contracts against the seals and joints to keep homeowners awake. Some products minimise this noise, but significant expansion and contraction is an inherent property of the material. It’s this movement against the seals and joints that creates gaps where leaks occur. Heat can also cause the gutters to twist and warp. With age, plastic tends to fade and discolour. With age also, UV light causes embrittlement in plastic and coatings so they become vulnerable to cracking and chipping.

Cast iron rainwater is tough, incredibly strong, lasts for years and is 100% recyclable. It’s cost effective and beautiful, available in eight Heritage colours as standard. A wide range of colours can also be ordered for bespoke projects. Protected by a three coat system applied under Apex certified factory conditions and installed and maintained properly, Alumasc cast iron rainwater can be expected to last over 100 years. Perfectly protected against the weather, gutters and downpipes should not need attention for up to 10 years, with regular maintenance thereafter.

Cast iron is ideal for period and conservation buildings, heritage public, listed buildings and self-build homes. It would not be cost effective on new mass-market housing where, if looked after properly it would probably outlast the building itself.

Plastic ‘cast iron’ effect rainwater is ideal for the mass-market. Cast iron is a premium solution to protect premium properties.