When it comes to rainwater systems, metal reigns supreme. Not only do metal gutters and downpipes last significantly longer than PVCu alternatives, but they are also a much more sustainable option, especially during current times when caring for the environment is more important than ever.
Although metal systems may have a higher initial cost, they offer exceptional lifetime value, are fully recyclable, and leave a lower carbon footprint compared to plastic.
But which metal should you choose? Whether you’re working on a modern home, a period restoration, or a commercial project, selecting the right metal rainwater system depends on factors like budget, strength, maintenance, and style.
This guide compares the four main types of metal rainwater systems—steel, cast aluminium, extruded aluminium, and cast iron—to help you make an informed decision.
Steel Rainwater Systems – Affordable, Strong & Contemporary
Steel Guttering, in our view, is the most cost-effective metal rainwater system, offering a sleek, modern look while maintaining excellent strength and durability.
We sell it in a range of colours, available for next working day delivery. There are 2 main brands on the market - Lindab guttering and Zambelli guttering (next day).
Key Benefits of Steel Gutters & Downpipes
✅ Affordable: The most budget-friendly metal option.
✅ Strong & Durable: Outperforms PVCu in strength, longevity, and performance.
✅ Minimal Expansion & Contraction: Resistant to thermal movement, meaning fewer joint failures.
✅ Eco-Friendly: Fully recyclable with a long lifespan.
✅ Stylish & Versatile: Available in various powder-coated finishes. This allows you to match it up to windows or fascia. E.g. if you have an aluminium coping in anthracite grey to match.
The Zambelli galvanised steel guttering in use on a UK property.
Installation & Suitability
📌 Effortless Installation – Designed for easy and straightforward fitting, these gutters are lightweight yet durable. They come with rubber-lined union connectors, which provide a secure and watertight connection without requiring additional sealants. This feature not only simplifies installation but also minimizes maintenance in the long run.
📌 Versatile Design – Suitable for a wide range of properties, these gutters seamlessly blend with both traditional and modern architectural styles. Whether you’re upgrading an older home or installing a drainage system in a newly built property, this guttering solution offers both functionality and aesthetic appeal.
Take a closer look at the Zambelli steel guttering installation guide here.
Black Zambelli (9005 Matte Black) With the Corrugated Metal Sheets
Pricing & Specifications Guide
💰 Guide Price: £24.53+VAT per 3-meter length of galvanised steel gutter (Standard 115mm, plain galvanised finish).
✔ Durable & Weather-Resistant – The galvanised steel construction ensures long-lasting performance, with excellent resistance to rust and corrosion. It's also backed by a 25 year product warranty (Zambelli).
✔ Low Maintenance – The colour-coated finish not only enhances the appearance but also provides an extra layer of protection against harsh weather conditions.
✔ Cost-Effective Solution – Offers a high-quality alternative to traditional plastic or zinc gutters, combining strength and longevity at an affordable price.
Cast Aluminium Rainwater Systems – Traditional, Strong & Lightweight
Cast aluminium is an excellent alternative to cast iron, offering a heritage look with a lighter weight and lower maintenance requirements.
Key Benefits of Cast Aluminium Gutters & Downpipes
✅ Extremely Durable: Rust-resistant and perfect for handling heavy rainfall.
✅ Mimics Cast Iron: Provides a heritage aesthetic but is lighter and easier to install.
✅ Long Lifespan: Typically lasts 25+ years with minimal maintenance.
✅ Eco-Friendly: 80% of aluminium systems are made from recycled materials.
✅ Available in 26 Unique Colours: Pre-coated for immediate installation.
Aluminium box gutter, also supplied by Trade Warehouse
Maintenance of Aluminium Guttering
A well-maintained aluminium gutter system can last for decades, preventing costly repairs and water damage to your property.
Down below is a detailed guide to keeping your aluminium gutters in the best condition.
Routine Cleaning: The Key to Longevity
Clearing out your aluminium gutters regularly is essential for ensuring a free-flowing drainage system. Blocked gutters can lead to water overflow, which may damage your home’s foundation, walls, and roof.
How Often Should You Clean?
- End of autumn: After most leaves have fallen, remove accumulated debris before winter sets in.
- Spring check-up: Inspect for any damage caused by heavy rainfall or winter storms.
- After storms: If you experience extreme weather, check for blockages and damage.
Best Practices for Cleaning
- Use gloved hands or a gutter scoop to remove leaves and debris.
- Never flush debris down the outlets—this can lead to stubborn blockages in the downpipes.
- Collect waste in a bucket or bag for easy disposal.
- Use a drainage rod if the downpipe is blocked, pushing from the top downward
White cast aluminium guttering.
Ensuring water flows smoothly through your aluminium gutter system means checking for blockages in both the gutters and the downpipes.
- Check for clogs in the downpipe by running water through it. If water doesn’t drain freely, use a drainage rod to clear obstructions.
- Install leaf guards or gutter brushes to minimise debris build-up and reduce cleaning frequency.
- Trim overhanging branches to prevent leaves and twigs from accumulating in the gutters.
Checking your aluminium gutters regularly helps detect minor issues before they become costly repairs.
Things to Always Keep an Eye Out For:
- Leaks at joints or seams: Apply waterproof gutter sealant to fix small leaks.
- Loose brackets or sagging sections: Tighten or replace brackets if needed.
- Peeling paint or oxidation: A white, chalky residue indicates oxidation—clean and repaint if necessary.
- Dents or warping: Heavy impacts from debris or ladders can bend aluminium gutters, reducing their efficiency.
Painted black cast aluminium gutters on a UK heritage property.
Installation & Suitability
Installing aluminium guttering might seem daunting at first glance, but with the right tools and guidance, it’s a manageable task that can significantly improve your home’s rainwater management.
Brackets are the backbone of your guttering system—they keep everything in place, ensuring durability and stability.
- Fix the Brackets: Use 6mm x 40mm (No12 x 1.5”) roundhead woodscrews to secure fascia brackets. Make sure they’re level and aligned with the gutter’s intended fall.
- Position Angles: Where the gutter changes direction, place an additional bracket near each angle joint for extra support.
Now, it’s time to fit the gutters into the brackets.
Here’s how to do it with finesse:
- Mount the Gutter: Lower the gutter onto the brackets, ensuring there's enough clearance for joints.
- Securing the Gutter: For half-round and beaded half-round profiles, clip the gutter into place by positioning the back of the gutter first, then pivoting it into the bracket while applying gentle pressure to the front.
- Jointing Cast Gutters: For cast aluminium gutters with spigot and socket joints, degrease the jointing surfaces with Rainclear solvent cleaner. Apply two 6mm beads of DOW791 silicone sealant around the fixing hole before securing with M6 x 20mm nuts, bolts, and washers.
Pro Tips for a Flawless Finish
- Handle with Care: Aluminium, while robust, can dent if mishandled. Always support longer lengths when moving them.
- Protect the Coating: Avoid harsh tools that could scratch the factory-applied powder coating, which protects the metal and keeps your gutters looking sharp.
- Consider Professional Help: While installing gutters is doable as a DIY project, hiring professionals can save you time and ensure the job is done safely, especially if you're not comfortable working at heights.
💰 Guide Price: £56.31 for a 1.83m powder-coated cast aluminium gutter (125mm half-round).
Modern Extruded Aluminium – Sleek, Lightweight & Long-Lasting
For a contemporary rainwater solution, extruded aluminium guttering is the go-to choice.
Stronger than steel and lightweight, it is a top pick for modern homes and commercial buildings.
Key Benefits of Extruded Aluminium Gutters & Downpipes
✅ Exceptionally Durable: Made from 2-3mm thick aluminium, thicker than steel.
✅ Highly Flexible: Can be fabricated to fit awkward architectural details.
✅ Rust-Resistant: Naturally forms a protective oxide layer.
✅ Huge Profile & Colour Options: Available in 26 standard colours & various designs.
✅ Snap-Together Installation: Some models use 'SnapIt' technology for quick installation.
The anthracite grey modern aluminium guttering
Maintenance Needs
Cast iron guttering is a durable, heavy-duty choice, known for its ability to last well over 50 years with proper care.
While it is inherently strong and low-maintenance compared to other materials, it does require periodic upkeep to prevent deterioration and ensure optimal performance.
Here’s how to keep your cast iron gutters in top condition for decades to come...
🔹 Clear gutters twice a year—after autumn leaves fall 🍂 and before spring rains 🌧️.
🔹 Check for rust and repaint if needed to protect against corrosion. 🎨
🔹 Avoid damage—never lean ladders directly against the gutter. 🚧
🔹 Inspect joints & brackets for wear and tighten if loose. 🔩
🔹 Apply sealant if leaks appear to maintain a watertight system. 💧
Cast Iron Rainwater Systems – The Ultimate in Longevity
Cast iron guttering is the most expensive metal rainwater option but offers an unmatched lifespan of 50-100+ years. This beats the other metal rainwater systems.
It is the go-to choice for heritage properties and listed buildings.
Key Benefits of Cast Iron Gutters & Downpipes
✅ Unrivalled Strength & Longevity: Lasts a lifetime with proper maintenance.
✅ Authentic Traditional Look: Perfect for restoration projects & period properties. ✅ Highly Sustainable: Fully recyclable and eco-friendly.
✅ Thicker & Heavier: Provides superior durability against extreme weather conditions.
✅ Pre-Painted or Site-Paintable: Comes in black factory finish or primer-coated for on-site painting.
Installation & Suitability
See our full cast iron installation guide here.
Top Tips When Installing Cast Iron
🔹 Check the Fixing Background – Ensure fascia boards are level, secure, and capable of supporting gutter weight. 📏🔩
🔹 Bracket Placement – Install brackets at 915mm centres, with extra support near outlets & angles (max 150mm from joints). 🔧
🔹 Set the Gutter Fall – Identify the highest & lowest points, ensuring a minimum fall of 1:600 for proper drainage. 📐
🔹 Position Outlets & Angles – Use a plumb line or laser to align over gullies, supporting with at least one bracket per outlet & angle. 🎯
🔹 Fix Gutter Lengths – Place the gutter into the brackets, securing the rear first, then pivoting the front edge into place. 🔄
🔹 Seal Joints Properly – Apply two 6mm beads of low modulus sealant, insert the spigot end, allowing a 3mm expansion gap. 🏗️🔗
🔹 Bolt & Secure – Push bolts through, ensuring sealant fills the slot before tightening nuts & washers. Do not overtighten to avoid leaks. 🔩🚫
🔹 Final Touch – Clean off excess sealant & smooth the internal face for a watertight finish. 🧽💧
🔹 Cut Lengths? – De-burr & touch up with supplied paint before installation for long-lasting protection. 🎨🛠️
💰 Guide Price: £47.24 per 3m length of powder-coated extruded aluminium gutter (115mm half-round).
Maintenance Needs
🔹 Annual Cleaning – Clear debris from gutters & outlets to prevent blockages. 🧹🍂
🔹 Check for Rust – Inspect for corrosion, especially at joints & brackets. 🛠️🔎
🔹 Repaint Every 5-10 Years – Apply rust-resistant paint to protect against weather damage. 🎨🛡️
🔹 Inspect & Secure Brackets – Tighten loose fittings and replace any damaged brackets. 🔧🔩
🔹 Seal Joints Properly – Use a high-quality sealant to prevent leaks & maintain a watertight system. 💧🚫
🔹 Avoid Heavy Impacts – Never lean ladders against gutters; use a ladder stand-off. 🚧🪜
🔹 Check Downpipes – Ensure proper water flow & clear any blockages with a drainage rod. 🌊🚰
🔹 Prevent Water Damage – Look for signs of overflow or pooling water that may indicate an issue. 🚨🏠
🔹 Monitor Paint Condition – Touch up areas where paint is peeling to prevent exposure to moisture. ✨🔨
Installation & Suitability
📌 Heavy & Requires Two-Person Installation: Best done by professionals.
📌 Suitable for: Listed buildings & traditional architecture.
💰 Guide Price: £47.24 (inc VAT) per 1.83m length of pre-painted cast iron gutter (100mm half-round).
Comparison Table: Which Metal Rainwater System is Right for You?
| Feature | Steel | Cast Aluminium | Extruded Aluminium | Cast Iron |
|---|---|---|---|---|
| Initial Cost | £ | £££ | ££ | ££££ |
| Lifespan | 20-25 years | 25+ years | 25+ years | 50-100+ years |
| Strength | Strong | Very Strong | Very Strong | Extremely Strong |
| Rust-Resistance | Coated Protection | Naturally Resistant | Naturally Resistant | Requires Maintenance |
| Weight | Light | Medium | Light | Heavy |
| Best For | Modern & Traditional | Period & Modern | Contemporary & Commercial | Heritage & Listed Buildings |
Final Verdict: Which One Should You Choose?
-
On a budget? → Choose Steel.
-
Want a cast iron alternative? → Choose Cast Aluminium.
-
Need a sleek, lightweight system? → Choose Extruded Aluminium.
-
Restoring a period property? → Choose Cast Iron.
No matter your choice, metal rainwater systems outperform PVCu in durability, aesthetics, and sustainability. Invest wisely, and your gutters will last for decades! 🎯
Which system do you prefer? Drop a comment below! ⬇️