Shopping Summary
| Total edge length | — |
| Waste-adjusted length | — |
| Stick length / coverage | — |
| Pieces to buy | — |
| Estimated cost | — |
Common Roof Examples
| Roof | Approx. drip edge |
|---|---|
| Small shed | 40 – 80 ft |
| Garage | 100 – 160 ft |
| Average house | 180 – 300 ft |
| Large house | 300 – 450 ft |
Drip Edge Types
| Type | Profile and use |
|---|---|
| Type C | L-shaped with a bottom hem; common, simple eave and rake edge |
| Type D | T-shaped with a lower flange that kicks water further off the fascia |
| Type F | Extended face, often used over existing shingles or at rakes |
| Gravel stop | Raised lip for flat or low-slope roofs to hold gravel ballast |
Material Comparison
| Material | Notes |
|---|---|
| Aluminum | Most common, rust-proof, paintable, inexpensive, light |
| Galvanized steel | Stronger and stiffer, good in high wind, can rust if the coating is scratched |
| Copper | Premium, long-lasting, develops a patina; used on high-end and historic roofs |
What Is Drip Edge?
Drip edge is the L-shaped or T-shaped metal flashing installed along the edges of a roof, at the eaves and rakes, to direct water away from the fascia and into the gutter instead of letting it wick back under the roof. It protects the wood edge of the roof from rot, helps shingles overhang correctly, and is required by most building codes. This calculator works out how many sticks of drip edge to buy: enter your eave and rake lengths, choose a stick length, add a waste factor, and it returns the pieces to grab and the cost.
How Much Drip Edge Do I Need?
Add up the linear feet of every roof edge that gets drip edge, which is the eaves along the bottom and the rakes up the gable sides, plus any dormers or porch roofs. Add a waste factor of 5 to 15 percent for cuts, corners, and the overlap where pieces join, then divide by the usable length of each stick. Because each piece overlaps the next by a couple of inches, a 10-foot stick covers a little less than 10 feet, which this calculator accounts for so the piece count is realistic.
Drip Edge Placement
Placement differs between the two edges. Along the eaves, drip edge goes under the underlayment so water running down the felt sheds over the metal and into the gutter. Along the rakes, drip edge goes over the underlayment so wind-driven rain cannot get under it. Pieces overlap by about two inches in the direction of water flow, and corners are mitered or overlapped. Getting the under-versus-over detail right at the eaves is what keeps water out of the roof deck.
Drip Edge Types and Materials
Type C is a simple L-profile with a hemmed bottom edge; Type D, sometimes called a T-style, has a wider lower flange that throws water further from the fascia and is increasingly required; Type F has an extended face for going over existing shingles or at rakes; and a gravel stop is used on flat roofs. Aluminum is the most common material because it is cheap and rust-proof, galvanized steel is stronger for high-wind areas, and copper is the premium choice for longevity and looks. Match the material to your climate and budget.