Preserving cast iron rainwater systems on listed properties
Posted on by Peter Bell
Peter Bell – Conservation Advisor – Listed Property Owners Club
By law, any works to alter, extend or demolish a listed building in a way that affects its character as a building of special interest require listed building consent from the local planning authority.
This could include the replacement of rainwater pipes and gutter systems, for example. Not only are they part of a building’s heritage and character, but they also keep water out of its fabric, and they are therefore vital to its structural integrity.
Increasingly we’re seeing a trend towards owners taking a risk on replacing existing rainwater pipes and gutters on listed properties, which are likely to be cast iron, with inferior, plastic products.
I believe that this decision is often influenced by the builder who is carrying out the work on the property, as they may consider plastic products to be easier to install than cast iron.
If caught out by the local planning authority, listed property owners who opt to replace cast iron guttering with inferior materials will be instructed to reinstall cast iron or, in extreme cases, they could face criminal prosecution. Granted, many local planning authorities don’t have the time or resource to go down the legal route, but the threat remains and, in my opinion, the law should be enforced.
This seems to be a problem that is unique to rainwater and gutter systems as many listed property owners tend to believe that ‘cutting corners’ with these alterations carries less risk of being noticed by the local planning authority, compared with other remedial work such as replacing windows with uPVC, for example.
However, replacing cast iron with plastic is a short-term fix. Over time plastics can become brittle and lose colour. They’re also susceptible to thermal movement, which can lead to leaking downpipes. I also find the rattling of plastic guttering in high winds quite annoying.
By contrast, cast iron pipes and gutter systems are naturally durable and can last up to 100 years, that’s five times as long as a typical plastic system and, if installed correctly, they require little structural maintenance throughout their life, only periodical painting. Cast iron products can also be supplied with a factory applied top coat, helping to reduce the time and cost associated with installation and ongoing maintenance.
The profile designs of cast iron products have also changed very little over the years. Therefore new components can easily be integrated into existing systems, helping listed property owners to avoid the costs of complete replacement.
Preserving and maintaining an original rainwater system really does contribute immensely to the external character of a property. Decorative features like hopper heads, or rainwater heads as they are also known, can add further interest and a unique silhouette to a building, especially when accompanied by other ornate castings like decorative ear bands. They can also provide an indication of the building’s age and are especially important to the architectural value of a property. Whichever way you look at it, cast iron has an aesthetic charm that simply cannot be matched by other materials.
As ‘custodians’ of these buildings, which hold both local and national importance, listed property owners should look no further than cast iron when it comes to replacing rainwater pipes and gutter systems.