Copper vs Aluminum Building Wire: What to Confirm Before Ordering

Updated: August 5, 2026

“Building wire” covers a broad range of insulated conductors used in electrical projects. Product listings may include copper or aluminum conductors, several insulation types, solid or stranded construction, numerous colors and different reel or coil sizes.

Knowing these differences helps contractors prepare accurate material requests. Final conductor selection, sizing and installation requirements must come from the project documents and a qualified electrical professional.

What is copper building wire?

Copper building wire uses copper as the conductor material. It is available in many sizes, colors, insulation types and packaging configurations.

Copper products may be supplied as solid or stranded conductors. They can also differ in flexibility, overall diameter, temperature rating and suitability for different environments.

Browse Revco’s copper THHN and T90 building wire to compare available product specifications.

What is aluminum building wire?

Aluminum building wire uses aluminum alloy as its conductor material. Depending on the product and project, it may offer practical advantages involving weight, handling or material cost.

Aluminum and copper conductors of the same nominal size should not be assumed to have identical dimensions, ratings or termination requirements. The conductor material and exact product specification must be confirmed before ordering.

Revco’s building wire category includes copper and aluminum product families with specifications for comparison.

Can copper and aluminum wire be substituted?

Do not substitute one conductor material for another without approval. A change in conductor material can affect conductor size, raceway requirements, equipment compatibility, terminations and other parts of the approved design.

If the specified product is unavailable, send the proposed alternative to the contractor, engineer or other authorized decision-maker. Obtain written approval before releasing the order.

What to confirm before ordering building wire

1. Conductor material

Confirm whether the project calls for copper or aluminum. Do not rely on a previous order, similar job or assumed standard.

2. Wire type

Record the complete wire designation shown in the plans, specifications or approved material list. Similar-looking wire products may have different insulation systems, ratings and permitted uses.

When replacing existing material, photograph the complete printed legend on the conductor or original reel label.

3. Conductor size

Supply the conductor size specified by the responsible electrical professional. Revco can help locate products matching that specification, but conductor sizing should not be determined from a product description or general online guide.

4. Solid or stranded construction

Confirm whether the order requires solid or stranded conductors. These constructions differ in handling, flexibility and product availability.

The requested construction should match the project specifications and compatible equipment.

5. Insulation and product ratings

Provide the exact insulation designation and any voltage, temperature, moisture, sunlight, oil, flame or other ratings required by the project.

Do not assume every product in a wire family has the same ratings. Verify the manufacturer’s documentation for the exact catalog number being ordered.

6. Conductor color

Include the required color for each conductor. Color availability may vary by material, size, wire type and packaging.

If the requested color is unavailable, do not approve a substitute without confirming the project’s identification requirements.

7. Length and quantity

Provide the required quantity for each wire type, size and color. If multiple runs are involved, identify the required lengths separately when practical.

Base the order on the approved project takeoff. Do not add an arbitrary percentage without checking with the person responsible for estimating the material.

8. Packaging

Building wire may be available on reels, in coils or in cut lengths. Available packaging depends on the product, conductor size and branch inventory.

Confirm reel size, cut-length availability, minimum quantities, lead time and return restrictions with your selected Revco branch before placing the order.

9. Compatible equipment and accessories

Confirm that lugs, connectors, terminals and other equipment are approved for the specified conductor material, size and construction.

Include manufacturer and catalog information for existing equipment when compatibility needs to be checked.

Building wire quote checklist

Include the following information with your quote request:

• Job name and location
• Copper or aluminum conductor
• Complete wire type or designation
• Conductor size
• Solid or stranded construction
• Required color
• Insulation and product ratings
• Quantity or total footage by color
• Preferred reel, coil or cut-length packaging
• Manufacturer or approved equal requirements
• Required date
• Pickup or delivery preference

Attach the relevant specification, wire schedule, approved submittal or photograph of the existing conductor legend when available.

Common ordering mistakes

• Requesting “building wire” without identifying the conductor material or wire type
• Assuming copper and aluminum are direct substitutes
• Leaving conductor color off the order
• Ordering by size without confirming solid or stranded construction
• Assuming every product has the same environmental ratings
• Ordering fittings or equipment without checking conductor compatibility
• Failing to confirm reel size or cut-length availability
• Approving a substitution without written authorization

Frequently asked questions

Is copper building wire better than aluminum?

Neither material is automatically better for every project. The approved design, equipment, conductor requirements and installation conditions determine which material is appropriate.

Can I order the same size in aluminum instead of copper?

Do not make that substitution without professional review and approval. Changing conductor material can affect more than the material named on the purchase order.

Does Revco sell building wire by the foot?

Cut-length availability varies by product and branch. Ask your selected Revco location to confirm available lengths, minimum quantities and lead time.

What should I send if I am matching existing wire?

Send clear photographs of the full printed conductor legend and any reel or package labels. Include the conductor size, material, color, approximate required length and information about the equipment it must match.

Can Revco determine the correct conductor size?

Revco can help source wire that matches an approved specification. Conductor sizing and wiring-method decisions must be made by the project’s qualified electrical professional.

Ordering building wire on Long Island

Revco supplies building wire and related electrical products to contractors and trade professionals across Long Island. Product selection, packaging and cut-length availability may vary by item and branch.

Start with Revco’s wire, cord and cable category or contact your preferred branch with the approved specifications.

Visit the Revco locations page to find the nearest Long Island branch.

About Revco Lighting & Electrical Supply

Since 1978, Revco Lighting & Electrical Supply has served contractors, builders and trade professionals across Long Island. Our team helps customers source lighting and electrical products for residential, commercial and industrial projects.

Call (631) 283-3600 or contact your preferred Revco branch for product availability and quote assistance.