What Drip Edge Does
Drip edge is a thin, L-shaped strip of metal (aluminum, galvanized steel, or occasionally copper) installed at the edges of a roof -- along the eaves (horizontal edges) and the rakes (sloped edges). It serves several functions:
- Directs water off the edge of the roof and into the gutter rather than letting it run down the fascia
- Prevents water from wicking back under the shingles at the eave -- a process called capillary action that causes fascia rot over time
- Provides a clean termination edge for shingles and underlayment
- Helps keep the gutter properly positioned under the shingle edge
Where Drip Edge Goes
- Eaves: Installed over the fascia, under the underlayment. This sequence allows water that gets under the shingles at the eave to drain onto the drip edge and into the gutter.
- Rakes: Installed over the underlayment (not under it like at eaves). This ensures water running off the side edge of the roof does not get underneath the underlayment.
The sequence matters: eave drip edge goes on first (under underlayment), rake drip edge goes on last (over underlayment). Reversed installation defeats part of the purpose.
Signs of Drip Edge Problems
- Fascia board that is soft, rotted, or shows paint failure below the shingle edge
- Gutters pulling away from the fascia
- Water staining or rot visible below the gutter line
- No visible metal edge at the shingle line when viewed from the gutter
Related: Gutter and Roof Drainage Guide
Frequently Asked Questions
Is drip edge required by code?
Yes. The International Residential Code (IRC) requires drip edge at eaves and rakes on new roof installations. Many older roofs were installed without it or with inadequate drip edge. During a re-roof, installing proper drip edge should always be included.
Can I install drip edge myself?
The installation is mechanically simple on accessible eaves. However, improper drip edge installation -- particularly the overlap and sequence with underlayment -- can create the problems it is supposed to prevent. Most roofing professionals install drip edge as part of a complete re-roof, and it is not a large line item. Including it in any professional repair or replacement is the sensible choice.
What happens if drip edge is missing or damaged?
Without drip edge: water from the roof edge can wick back under the shingles and rot the fascia board. Gutters may pull away from the fascia over time from water weight and ice. Fascia rot is a common consequence of missing drip edge that many homeowners do not connect to the roofline.
Find Help in Your City
Installation requirements may vary by local code. Consult a licensed roofing contractor for professional guidance.