6 Best Copper Rivets for Securing Shim Laps to Choose

Securing shim laps and metal detailing requires more than just picking a fastener off a shelf. Because these components are often exposed to extreme thermal expansion, vibration from wind uplift, and constant moisture cycling, the material integrity of the fastener is paramount. Using standard galvanized steel in a copper or lead-coated copper system creates a galvanic reaction that will destroy the roof in a few short seasons. Solid copper rivets offer the necessary ductility and corrosion resistance to outlast the surrounding metal, provided the right gauge and style are matched to the specific installation requirement.

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Hanson 9 Gauge Copper Truss Head Rivet: Best Overall

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The Hanson 9 gauge truss head rivet is the gold standard for those who prioritize a low profile and maximum surface contact. The truss head design offers a wider footprint than standard round heads, which distributes clamping force across a larger area of the metal sheet.

This is critical when working with thin copper flashing or sensitive shim laps where tearing the base metal is a constant risk. By spreading the load, the truss head minimizes the chance of “dimpling” the metal during the peening process, which helps maintain a clean, professional aesthetic on visible architectural details.

For general roofing contractors who need a reliable, “do-it-all” fastener, this is the safest choice. It balances sheer strength with enough malleability to be set easily with a standard hammer and rivet set.

Jay-Cee #9 Solid Copper Rivets: Top Value Pick

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Jay-Cee rivets are the go-to for high-volume jobs where efficiency and material cost are major project drivers. While they lack the aesthetic refinement of specialized architectural heads, they provide a rock-solid, code-compliant connection that performs perfectly in concealed lap conditions.

The #9 sizing is a sweet spot for most standard flashing and metal roofing gauges. These rivets hold their shape well under the force of a hammer strike, ensuring that the shank expands to fill the hole completely, which is essential for preventing water migration through the fastener site.

Choosing these saves budget without sacrificing the structural integrity of the roof. If the application is hidden under a ridge cap or tucked behind a drip edge, there is little reason to spec a more expensive alternative.

Stortz Solid Copper Slating Rivets: Slate Pro Pick

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Slate roofs are a unique beast, requiring fasteners that can be set in tight, difficult-to-reach areas without damaging the brittle surrounding material. Stortz rivets are specifically engineered for the nuance of slate work, where the rivet must be driven into a hole that is often precut through stone and metal.

These rivets are optimized for “blind” installation, meaning the installer often doesn’t have the luxury of a perfect visual on the underside. They are designed to mushroom predictably when struck, creating a tight, low-profile seal that doesn’t hold moisture or catch debris.

When replacing or installing new slate copper work, deviating from a dedicated slate rivet often leads to cracked tiles or compromised seams. Always prioritize this professional-grade option when the cost of a failed slate repair far outweighs the marginal cost of the fastener.

McMaster-Carr 1/8″ Flat Head Rivets: Versatile

McMaster-Carr is the industry standard for when a project calls for a non-standard size or a specific head shape not found at traditional roofing suppliers. Their 1/8″ flat head rivets are ideal for custom fabrication, such as decorative gutters or small metal patches where a protruding head would interfere with a flush finish.

Because they offer such a wide range of lengths, these are the best choice for through-fastening multiple layers of metal. It is essential to choose a length that allows for exactly 1.5 times the shank diameter to protrude beyond the surface for proper peening.

These are not specifically marketed as “roofing rivets,” but their metallurgical quality is high enough for professional use. Use these when precise dimensions are required for custom metalwork or when an existing installation has non-standard hole diameters.

Rivet & Fastener 12 Gauge Round Head: Heavy Duty

When a project involves heavier-gauge copper or thick lead-coated accessories, the standard 9 gauge rivet often lacks the shear strength needed to hold under heavy snow loads or wind-driven vibration. The 12 gauge round head provides the extra backbone needed for these heavy-duty scenarios.

The round head design is thicker than a truss head, providing more material for the hammer to strike, which is useful when working overhead or in cramped conditions where a perfectly square strike is difficult. They feel more substantial in the hand and offer a more robust mechanical connection for structural metal components.

While they are more difficult to set than thinner rivets, they provide unmatched security. Reserve these for areas where the fastener might be subject to mechanical stress rather than just holding two light sheets of flashing together.

CopperNails.com Solid Copper Rivet: For Flashing

Flashing is the most common place to encounter moisture failure, making the choice of rivet critical. CopperNails.com produces rivets that are specifically tempered for long-term immersion in environments where heavy condensation or standing water is common.

The advantage here is the consistency of the copper alloy, which resists work-hardening—a process where metal becomes brittle after being bent or hit. If the rivet work-hardens too quickly during installation, it can crack under the constant expansion and contraction cycles of a roof, leading to silent, slow leaks.

These rivets are perfect for base-flashing to vertical walls, chimney transitions, and roof-to-wall interfaces. When the project involves high-performance building envelopes, starting with a rivet engineered for material stability is a proactive defense against callback work.

Choosing Rivet Gauge Length and Head Style

Selecting a rivet starts with the metal thickness of the materials being fastened. A good rule of thumb is that the rivet shank should be slightly smaller than the hole—usually by no more than 1/16″—to allow for expansion while minimizing play.

Head style is primarily a function of aesthetics and clearance. Use truss heads for thin, visible flashing to avoid ugly protrusions, but opt for round heads on structural components that require extra material for heavy-duty anchoring.

Length is the most critical technical factor. If the rivet is too short, the head won’t form correctly; if it is too long, the shank will bend sideways rather than mushrooming, creating a weak, lopsided seal that will eventually leak.

Solid Rivet vs. Copper Nail: When to Use Each

Solid rivets and copper nails might look similar, but they perform very different mechanical functions. A solid rivet is meant to be peened on the backside to create a permanent, mechanical clinch that can resist tension and vibration.

Copper nails, by contrast, are driven into wood or substrate and rely on the friction of the wood fibers for holding power. Using a nail to secure two metal sheets together without a wood backing is a recipe for failure, as the metal will eventually wallow out the hole and loosen.

If the joint involves metal-to-metal contact, always use a rivet. If you are securing metal to a wood nailer or deck, a copper nail or screw with a neoprene washer is the correct choice.

Essential Tools for Setting Solid Copper Rivets

A basic ball-peen hammer is not enough to set a solid rivet professionally. You need a dedicated rivet set, which is a tool with a cup-shaped depression that matches the head of the rivet, and a bucking bar or anvil to hold the backside.

The bucking bar is perhaps the most overlooked tool in the kit; it acts as a heavy metal backing that provides the counter-force needed to swell the rivet shank. Without a solid bucking bar, the force of the hammer simply pushes the rivet through the hole instead of mushrooming the end.

Keep a pair of flush-cut nippers or high-quality side cutters on hand to trim the shank to the correct length before peening. Proper preparation—trimming and backing—is what separates a job that lasts twenty years from one that fails in five.

How to Properly Peen a Rivet for a Watertight Seal

Peening is an art of patience and technique rather than pure force. Begin by ensuring the surfaces are tight together, then trim the rivet shank so that it sticks out exactly 1/8″ to 3/16″ past the material thickness.

Use the ball end of the hammer to lightly tap the edges of the shank, folding the metal over in a circular, spiraling pattern. Gradually work from the center of the shank outward toward the edges to ensure the copper expands and “plugs” the hole completely.

Once the shank begins to mushroom, use the flat end of the hammer to flatten the newly formed head against the base metal. The goal is a smooth, tight seal that exerts constant inward pressure on the two pieces of metal, creating a gasket-like effect that keeps moisture out of the fastener hole.

Properly selected and installed, solid copper rivets are virtually permanent fasteners that require zero maintenance over the life of the roof. Matching the gauge, length, and tool technique to the specific metal profile eliminates the most common causes of flashing failure. Rely on these methods to ensure the integrity of every lap and seam on the project.