Build cost basics: Guide to rainwater goods prices
e Build It Estimating Service’s Adrian Wild compares the upfront and lifespan costs of fitting different types of guttering for your home building project
We get our fair share of wet weather in the UK. According to the Met Office, if you live in Wales, Northern Ireland or the western regions of England, you can expect up to around 4m of rainfall per year. Moisture and buildings don’t mix well, so it’s vital your house is designed to collect and channel water away properly. If rain saturates the core materials, the property could suffer mould and decay – and ultimately structural failure. Guttering is also a highly visible part of a home’s completed look, so you need to consider both function and aesthetics when making your selection.
Rainwater goods: the options
With reasonable maintenance, you should get decades of reliable service from a well-designed and properly installed rainwater management system. For this reason, in addition to upfront purchase prices, the table below shows the equivalent annual life cycle cost of each material (basically the installation cost divided by the expected years of service).
Costs and longevity will vary depending on the material. Some original Victorian cast iron gutters still perform superbly today (with regular repainting and repair). Modern PVCU products have a much shorter shelf life – but assuming you’ve specified good quality versions, they shouldn’t need much attention over time, which may be important for you. Here’s a quick guide to the pros and cons of each type:
PVCU Plastic is most affordable upfront and quality has improved dramatically, with better seals and more attractive profiles. Avoid ultra-cheap versions, as they may be prone to thermal expansion and contraction, which is likely to lead to leaks. An alternative is GRP (glass reinforced plastic), which is more expensive but can be moulded for a heritage feel.
Cast iron A premium product offering an authentic period look and long life. Modern factory-painted versions are strong, durable and come in a range of heritage-style colours. If your home has original cast iron guttering, look to conserve it.
Zinc Over time this metal forms a thin patina layer that protects it from the elements, but the change is practically invisible and contributes to excellent durability. It’s lightweight, simple to fit and looks great in contemporary settings.
Aluminium Available in modern or heritage styles, this is lightweight and easy to install. Powder-coated versions are durable and corrosion-proof, so they’re a low-maintenance and affordable choice. Cast aluminium products are made by pouring the metal into a mould to accentuate the traditional look, but they’re more expensive than powder-coated options.
Steel Popular for contemporary homes, steel is an affordable metal upfront. It’s lightweight and considered easier to handle than aluminium, with minimal thermal movement compared to plastic – but its lifespan is around half that of zinc or cast iron.