Choose drip edge by matching the metal to the roof's service life and climate, and the profile to the edge and gutters. A flashing that fails in 10 years on a 30-year roof means opening the roof edge twice.
Which drip edge material should you use?
For a typical asphalt shingle roof, aluminum is the standard choice: light, corrosion resistant, and easy to form on site. Use galvanized steel where wind exposure or long unsupported runs need extra stiffness. Reserve copper for copper roofs or premium long-life roofs, and vinyl only for temporary repairs.
The NRCA advises that the material type and thickness of a drip edge should be commensurate with the steep-slope roof system's expected service life. That rule is the decision test: the flashing should last as long as the roof it edges.
| Material | Strengths | Weaknesses | Best fit |
|---|---|---|---|
| Aluminum | Light, corrosion resistant, easy to cut and bend, available painted to match fascia | Thinner stock can dent; can be damaged by copper contact (see compatibility below) | Standard asphalt shingle roofs |
| Galvanized steel | Stiffer than aluminum, stands up to high wind | Heavier; the zinc coating can rust where scratched; incompatible with copper runoff | High-wind areas, long runs, commercial work |
| Copper | Very long life (75 to 100 years for soldered copper flashing per roofer reports), develops a patina | Highest cost; corrodes aluminum and galvanized steel downstream; runoff can discolor light surfaces | Copper roofs, historic or premium long-life roofs |
| Vinyl or plastic | Inexpensive, never rusts | Less durable than metal; can turn brittle in cold weather | Temporary repairs only |
Which profile fits your roof edge?
Profiles are usually named Type C, Type D, and Type F. The names vary by supplier, so confirm the shape on the product label, not just the letter.
| Profile | Shape | Typical use |
|---|---|---|
| Type C (L-style) | Simple 90-degree bend | Standard eaves and rakes on asphalt shingle roofs |
| Type D (T-style) | Extended lower lip that throws water farther from the fascia | Eaves in heavy rain or wind-driven rain, where water must clear the fascia |
| Type F (gutter apron) | Longer face that reaches down into the gutter | Eaves with gutters, or re-roofs where the new edge must cover the old one |
The NRCA fabricates metal drip edges in L-type or T-type and notes that shingles should extend about 1/4 to 3/4 in beyond an L-type vertical face, or sit at least flush to 3/4 in beyond a T-type edge. Use the gutter-apron profile at eaves with gutters so runoff lands in the trough instead of behind it.
What thickness should you buy?
Thicker metal resists dents and stays straighter on long runs. Aluminum drip edge is commonly sold around 0.019 to 0.024 in (0.48 to 0.61 mm). Galvanized steel stock is stiffer at the same price point and some roofer guides recommend at least 24-gauge for durability. Hemmed (folded) edges add rigidity and keep the metal from cutting the installer or the underlayment.
Read the product label before you buy. Thickness claims on generic listings are unreliable, and the label also states the profile, coating, and painted finish.
Which metal combinations should you avoid?
Do not put copper in the same drainage path as aluminum or galvanized steel. Copper sits high on the galvanic series, so in the presence of rainwater it corrodes the less noble metal. A GAF technical bulletin documents galvanic damage to aluminum near copper with moisture, and the Cornell architecture technology notes rate copper-to-aluminum contact as high-risk (avoid) and copper-to-galvanized steel as inadvisable.
The runoff alone can carry the problem: water flowing from copper onto aluminum or galvanized components corrodes them even without direct contact. Match the flashing metal to its neighbors along the whole edge, gutter, and downspout path.
Use aluminum nails with aluminum drip edge and copper nails with copper. Dissimilar fasteners corrode the flashing they hold.
Can copper drip edge stain shingles or siding?
Yes. As copper oxidizes it sheds ions that can leave green discoloration on light-colored surfaces directly below. Roofers report this streaking on siding and light shingles where copper runoff washes over them. If you choose copper, plan the drainage so runoff does not cross light-colored shingles, siding, or gutters, and isolate copper from any aluminum below it with a non-conductive barrier.
How do color and finish factor in?
Aluminum drip edge is widely sold with factory-painted finishes that match or contrast the fascia and gutter color. Paint is a cosmetic choice, not a corrosion upgrade: the coating protects only while it stays intact. Confirm the finish is rated for exterior exposure, and handle painted pieces gently during cutting and bending so the coating stays continuous.
Common material-choice mistakes
- Buying vinyl for a permanent roof edge and replacing it after cold-weather cracking.
- Choosing the thinnest aluminum and getting wavy edges that telegraph through the first shingle course.
- Pairing copper drip edge with aluminum gutters or galvanized flashing, then finding corrosion within a few seasons.
- Using steel or plain nails through aluminum drip edge, starting galvanic corrosion at every fastener.
- Picking a profile by letter only; Type F from one supplier can differ from Type F from another.
- Ignoring the gutter-apron profile on guttered eaves and letting runoff fall behind the gutter.
- Choosing a flashing that outlives the roof twice over while the neighbor flashing is disposable, or the reverse.
Sources and scope
- International Code Council, 2021 International Residential Code, Section R905.2.8.5 "Drip edge": drip edge required at eaves and rake edges of shingle roofs; 2 in (51 mm) minimum segment overlap; 1/4 in (6.4 mm) below the sheathing and 2 in (51 mm) back onto the deck; fastening at not more than 12 in (305 mm) on center; underlayment over the drip edge at eaves and under it at rakes.
- Professional Roofing (NRCA), "On the edge", 2019-06-01: metal drip edge in L-type or T-type configurations; material and thickness commensurate with roof service life; fastening about 12 in on center, staggered; consult shingle manufacturer instructions.
- GAF, Technical Bulletin TAB-R 2011-107, galvanic reaction between copper and aluminum: aluminum highly susceptible to galvanic corrosion in contact with copper plus moisture; documented incidents with standing water.
- Cornell Architecture, Building Technology notes, galvanic corrosion table: copper-aluminum contact high risk; copper-galvanized steel not advisable; match nail and screw material to flashing metal.
- Smith Roofing Exteriors, drip edge and gutter installation guide: aluminum commonly 0.019 to 0.024 in; Type C, D, and F profile roles; hemmed edges for rigidity.
- Mighty Dog Roofing, copper flashing FAQ: copper runoff can discolor light-colored surfaces below; copper must be isolated from aluminum; soldered copper flashing life 75 to 100 years.
Scope: the guidance here selects drip edge material and profile for steep-slope asphalt shingle roofs. The governing code, local amendments, shingle manufacturer instructions, product label, gutter material, and a qualified installer control the accepted material, profile, fasteners, and final order.
Review responsibility: Saleem Sial owns the published calculation, source, and editorial checks. Waseem Sial, External Reviewer and Engineer, remains listed for ongoing external review; no completed external-review date is claimed.
Next, use the drip edge measurement guide to turn this material choice into a piece count, or return to the Roofing Calculators hub for the full set of planning tools.
