Roofing Nails Copper or Aluminium - What Should I Use
Choosing the right roofing nail might seem like a minor detail, but it’s actually the literal "linchpin" of your home’s weatherproofing. Using the wrong metal can lead to the dreaded "galvanic corrosion", a fancy way of saying your nails will eat themselves (and your roof) over time.
What is Galvanic Corrosion
In simple terms, galvanic corrosion (often called electrolysis) is an electrochemical process where one metal essentially "sacrifices" itself to another. It happens when two different types of metal are in contact while exposed to moisture.
Think of it like a battery that nobody asked for. By putting two dissimilar metals together in the rain, you accidentally create a circuit that causes the "less noble" metal (in this case aluminium) to dissolve. Aluminium has a much more negative electrode potential compared to copper. When both metals are in contact with an electrolyte (such as water or moist air), the aluminium becomes the anode and corrodes, while the copper acts as the cathode and is protected.
When it comes to high quality roofing, the debate usually boils down to Copper vs. Aluminium. Here is everything you need to know to make the right call for your project.
1. Copper Roofing Nails: The Premium Standard
Copper nails are the "old soul" of the roofing world. If you are working on a heritage property or using high end materials like natural slate or clay tiles, copper is usually the non-negotiable choice.
The Positives (Pros)
- Supreme Corrosion Resistance: Copper is incredibly hardy, especially in coastal areas where salt spray would destroy steel nails in months.
- Longevity: A copper nail will often outlast the roofing material itself. We’re talking a lifespan of 50–100 years.
- Chemical Compatibility: It is the only choice for copper flashing and gutters. Using any other metal here would cause a chemical reaction that leads to leaks.
- Aesthetic Patina: Over time, copper develops a beautiful green patina that looks stunning on traditional buildings.
The Negatives (Cons)
- Price Tag: Copper is significantly more expensive than aluminium. It’s an investment in the "forever" of the building.
- Malleability: Copper is a relatively soft metal. If you’re a bit too heavy handed with the hammer, or if you’re driving into very dense, old-growth timber, they can bend more easily than aluminium.
2. Aluminium Roofing Nails: The Modern All-Rounder
Aluminium nails are the practical, cost effective heroes of modern roofing. They are lightweight, durable, and the standard choice for most asphalt shingle and some slate installations.
The Positives (Pros)
- Cost-Effective: You get great corrosion resistance without the "premium" price of copper.
- Weight: They are incredibly light, which makes carrying large quantities up a ladder a lot easier on the back.
- Self-Healing Properties: When aluminium is exposed to air, it forms a thin layer of aluminium oxide that protects the rest of the nail from further rusting.
- Versatility: They work brilliantly with modern synthetic roofing materials and most standard timber battens.
The Negatives (Cons)
- Not for the Coast: While they resist rust, they don't handle high-salt environments as well as copper or stainless steel.
- The "Softness" Factor: Like copper, aluminium is softer than steel. You need a steady hand and a clean strike to avoid wasting nails.
- Reaction to Treated Timber: Certain modern pressure treated timbers contain high levels of copper. If you drive an aluminium nail into them, the two metals will react, causing the nail to degrade prematurely.
The Golden Rule: Galvanic Corrosion
The most important takeaway should be this: Never mix your metals.
If you have copper flashing, you must use copper nails. If you use aluminium nails on copper flashing, the aluminium will corrode at an accelerated rate through a process called electrolysis. Your nails will essentially turn to dust, and your roof will literally slide off.
At-a-Glance Comparison - Copper vs Aluminium
| Feature | Copper Nails | Aluminium Nails |
| Best For | Slate, Clay, Heritage, Coastal |
Asphalt Shingles, Modern Slate |
| Durability | 75+ Years | 30–50 Years |
| Coastal Use | Excellent | Fair/Good |
| Cost | High | Low/Medium |
| Strength | Soft (Bends easily) | Moderate (Better than copper) |
Summary: If you are building for the next century or live within sight of the sea, go for Copper. If you are looking for a reliable, rust-resistant, and budget-friendly option for a standard modern roof, Aluminium is your best friend.
To view our range of copper or aluminium roofing nails, click the link below:
