Aluminum flashing is thin, formable sheet metal used to close the joints where a roof meets a wall, a chimney, a valley or a penetration, directing water back onto the roof covering instead of into the structure below. Aluminum is soft enough to be bent, cut and dressed with hand tools on site, and it forms a self-limiting oxide layer that keeps it from rusting the way uncoated steel does.

This 4 in. width is a common size for step flashing, roll flashing and repair pieces, where a narrow leg is worked under shingles or siding and the balance is turned up against the adjoining surface. It is cut with tin snips and fastened or bonded with roofing cement or sealant, depending on the detail.

Aluminum should be kept away from direct contact with fresh masonry, mortar and pressure-treated lumber, and separated from copper, since alkaline materials and dissimilar metals promote corrosion.

Key Features

• Formed from aluminum sheet, which resists rust and does not require painting for corrosion protection
• Soft enough to be cut with snips and bent or dressed to the roof detail by hand on site
• 4 in. nominal width suited to step, wall and penetration flashing details
• Lightweight compared with steel or copper flashing of the same gauge, easing handling on a roof
• Compatible with asphalt shingle, roll roofing and most siding assemblies
• Can be bedded in roofing cement or sealant and fastened with compatible nails

Applications

• Step flashing where a sloped roof meets a vertical wall
• Headwall and sidewall flashing on dormers and additions
• Flashing around chimneys, skylights and roof penetrations
• Valley and transition repairs on shingle roofs
• Counterflashing and patch work on existing roofs
• Drip and edge detailing at eaves and rakes

Product Details

• Product Type: Roof Flashing
• Material: Aluminum
• Nominal Width: 4 in.
• Sold By: Each

Specifications

1. Submit a quote request for this product
   
2. Our team reviews availability and pricing
   
3. We follow up with a detailed quote and next steps
   

Pricing, availability, and lead times may vary by product and quantity.

• Local pickup options available
• Delivery available depending on product and location
• Lead times vary based on availability and order size

Need Help?

Have questions or need help selecting the right materials?

Our team is happy to help.