A drip edge is a piece of roof trim which directs water into the gutters, ensuring that water ends up where it is supposed to go as it drains from the roof. In some homes, a drip edge is not necessary because of the way in which the roof is designed. In others, it is needed. These edges can be added while roofing is replaced, or they can be carefully inserted into an existing roof if the need for an edge is identified before the whole roof needs to be replaced.
Ideally, the roof overhang should direct the water into the gutters. In areas where there are no gutters, as seen on a gable, the roof overhang protrudes far out enough that any water which drips off ends up well away from the house. If the roof edge is too close to the edge of the walls, water ends up coating the sides of the house and may even end up inside the trim, flashing, and walls, creating serious problems. A drip edge addresses these problems without the need for drastic modification to a roof.
The drip edge fits under the roofing and roofing felt in any downward-facing areas of the roof. It can be adjusted to ensure that the water drips neatly into the gutters directly below it. Along gables, the edge goes under the roofing, but over the felt. In both cases, a zig zag pattern is used to attach it, and it is attached with care so that it lies flush with the flashing. This ensures that water cannot work its way into areas where it is not desired.
Metal and plastic are both used to make drip edges. The edges are available from many hardware and home supply stores, and people can also order custom products as needed. Installing this trim is not terribly complicated, although people do need to feel comfortable working at heights and working with their roofing. A contractor can also be hired to do the job. While installation occurs, it is a good idea to check for signs of rot, missing roof tiles, and any other problems which could lead to complications in the future.
A drip edge is useless without properly maintained gutters. The gutters and downspouts should be kept clean, with caps on gutter ends where no downspout is available. People should also be careful about how their downspouts drain. Many older homes have downspouts which dump water very close to the foundation, which is not a good idea. The downspouts should carry water well away from the foundation, directing it downhill so that it will drain harmlessly into the street or to a lower grade on the property.
By Mary McMahon
Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a About Mechanics researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.