It costs a few dollars a foot and most homeowners have never heard of it. But a missing drip edge is one of the most common reasons we find rotted fascia on older West Michigan homes, and code now requires it for a reason.
Quick answer: Drip edge is a metal flashing installed along the edges of a roof to carry runoff off the roof and into the gutter instead of back under the shingles onto the wood. The International Residential Code, which Michigan follows, requires it at both the eaves and the rakes. Without it, water wicks onto the fascia and sheathing, and in a West Michigan winter that wet edge rots. It is the small detail that protects the most vulnerable part of the roof.
Every roof has an edge, and the edge is where water wants to misbehave. Drip edge is an L-shaped or T-shaped strip of metal, usually aluminum or galvanized steel, installed along the perimeter of the roof before the shingles. One leg lies on the deck under the roofing; the other bends down over the edge and kicks slightly outward. That small bent lip does one job well: it takes water running off the roof and throws it clear of the wood, into the gutter or off the rake, instead of letting it curl back and cling to the fascia.
Without that lip, surface tension does something homeowners never expect. Water running off a bare shingle edge does not just fall. It hugs the underside of the shingle and wicks backward onto the fascia board and the exposed edge of the sheathing. Drip edge breaks that path. It is a tiny piece of the roof, easy to overlook on a walkaround, and it protects the parts that cost the most to repair when they rot.
Drip edge is not optional anymore, and the history is worth knowing. For most of the last century, drip edge was good practice but not a universal requirement, so plenty of older West Michigan homes were roofed without it. That changed when it became a nationwide requirement in the 2012 International Residential Code cycle. The current code, which Michigan adopts, spells out the specifics in Section R905.2.8.5, and the numbers are worth having when you review an estimate.
These are the published requirements from the International Residential Code, Chapter 9. A roof that skips drip edge or installs it short is not code compliant, which matters both for the roof's life and for the paperwork on any real estate transaction.
The trick with drip edge is that it goes in a different order at the two edges. This is the part that separates a roofer who follows the detail from one who nails metal on and moves on. At the eaves, the drip edge is installed first, directly on the deck, and then the underlayment and the self-adhering ice barrier lap over the top of it. That way any water traveling on top of the underlayment sheds onto the metal and off the roof. At the rakes, the order reverses: the underlayment goes down first, and the drip edge is installed over it.
Get that backward at the eaves, with the underlayment tucked under the drip edge, and water on the membrane can run behind the metal and onto the fascia, which is exactly the failure the drip edge was supposed to prevent. The eave detail also has to coordinate with the ice barrier our winters require, a layer we cover in our guide to ice-and-water shield and Michigan code. The drip edge and the ice barrier work together at the eave, and the sequence is not something to improvise.
This is not a theoretical code point. It is the single most common cause of edge rot we find. On a home with no drip edge, every rain and every snowmelt sends water wicking back onto the fascia board and the raw edge of the deck. In summer it dries between storms. In a West Michigan winter it does not. The National Weather Service Grand Rapids office tracks 40 to 60 freeze-thaw days in a normal winter, and through that stretch the roof edge can stay damp for weeks. Wet wood in cold cycles is wood that rots, and the fascia is the first to go.
By the time a homeowner notices peeling fascia paint or a soft board, the edge of the sheathing underneath is often gone too. That is the connection between the small missing flashing and the bigger repair, and it is why we treat the edge as a system, covered further in our guide to soffit and fascia repair. Adding proper drip edge during a reroof is the cheapest insurance on the roof against the most predictable rot.
Drip edge and gutters are supposed to be partners. Done right, the eave drip edge extends down over the back of the gutter so that water coming off the roof lands inside the gutter, not behind it. When there is no drip edge, or it is set too short or too high, runoff sneaks between the roof edge and the gutter and pours down the fascia, staining and soaking the very board the gutter was hung on. If your gutters are clean and you still see water running down the fascia in a storm, a missing or misaligned drip edge is a prime suspect. The interaction with the gutter is part of why we look at the two together on our gutter work.
Drip edge is simple, which is exactly why it gets done carelessly. The failures repeat from house to house.
None of these are exotic. They are the difference between a roof edge that sheds water for thirty years and one that quietly feeds the fascia until it fails. On any full tear-off we strip the edges clean, replace any rotted fascia and deck, and set new drip edge in the correct order before the underlayment ever goes down.
Older Grand Rapids homes complicate the edge. Many century-old houses in Heritage Hill and the downtown neighborhoods were built with built-in gutters or deep ornamental fascia and never had a modern drip edge. Retrofitting the detail on a historic roof takes care, because the edge has to stay watertight without altering the look of the eave or the built-in gutter it was designed around. It is the same restraint we bring to built-in gutter work: modern water management, integrated so the historic edge still reads the way it was meant to.
Drip edge is the least expensive flashing on the roof and one of the most important. It carries water off the edge and into the gutter instead of back onto the fascia and deck, and Michigan code requires it at both eaves and rakes because leaving it off is a proven way to rot a roof edge. The details are unglamorous, a 2-inch lap, a quarter inch of overhang, the right order at each edge, but they are the difference between a dry edge and a slow, expensive failure. If your home predates 2012 or was roofed on the cheap, it is worth finding out whether it has drip edge at all before the fascia tells you the hard way.
Our residential roofing crews set drip edge to code and to the home, and our cost guide shows where the edge details fit in a full roof. We have kept West Michigan roof edges dry, one detail at a time, since 1994.
Yes. The International Residential Code, which Michigan follows, requires a drip edge at both the eaves and the rake edges of asphalt shingle roofs. It became a nationwide code requirement in the 2012 code cycle. Many older West Michigan homes were roofed before that, which is why so many have no drip edge and show fascia rot as a result.
Drip edge is a metal flashing at the roof's edges that directs runoff off the roof and into the gutter instead of letting it curl back under the shingles onto the wood. It keeps water off the fascia and sheathing, stops capillary wicking under the edge, and gives the shingles a firm, straight line to overhang. It is small, cheap, and it protects the most rot-prone parts of the roof.
Both. Code requires drip edge at the eaves, the horizontal lower edge above the gutter, and at the rakes, the sloped gable edges. The two are installed in a different order relative to the underlayment: at the eaves the underlayment goes over the drip edge, and at the rakes the underlayment goes under it. That order is what makes the water shed correctly.
On the rake edges it can sometimes be added by carefully lifting the shingle edge. At the eaves it is difficult to do right after the fact, because drip edge belongs under the underlayment and ice barrier there. The clean, correct time to install drip edge is during a reroof, when the edges are open and it can be integrated in the proper order.
Runoff curls back under the shingle edge and wicks onto the fascia and the edge of the sheathing. Over West Michigan winters that edge stays wet, and wet wood rots. Missing drip edge is one of the most common reasons we find soft, rotted fascia and delaminated deck edges on older homes, and it often goes unnoticed until the fascia is failing.
It depends on the edge. At the eaves the drip edge is installed first and the underlayment, including the ice barrier, laps over the top of it, so water on the underlayment sheds onto the metal. At the rakes it reverses: the underlayment goes down first and the drip edge is installed over it. Getting this backward defeats the purpose.
Roof Repair of Grand Rapids has been installing, repairing, and preserving roof systems on West Michigan homes since 1994. We build roofs from the edge in: drip edge set to code in the right order, a self-adhered ice barrier at the eaves our winters demand, and fascia and sheathing repaired before the new roof goes on. On a downtown ranch or a Heritage Hill original, the edge details get the same attention as the field. Climate figures reference the National Weather Service Grand Rapids office, and code references follow the International Residential Code, Chapter 9.