Drip edge is absent along the eaves of a shingle roof. What is the consequence?

Drip edge is a small L-shaped metal flashing at the roof perimeter, and its job is to control where water leaves the roof. Without it, water running off the shingle edge does not fall clear — surface tension pulls it back around the shingle's underside, where it wets the sheathing edge and runs down the fascia. The damage accumulates in the places least visible from the ground: the exposed edge of the sheathing swells and delaminates, the fascia's back face rots behind its paint, and in cold climates the wetted edge contributes to ice damming. Drip edge also directs water into the gutter rather than behind it, which is why its absence often shows up as fascia rot immediately above an apparently functioning gutter. The inspector reports the missing flashing and the areas where consequential damage is visible.

Without drip edge, runoff wraps back under the shingle edge by surface tension and wets the sheathing edge and the fascia behind it. Water is also more likely to run behind the gutter rather than into it.

Drip edge is installed at eaves and rakes to direct water away from the fascia and the sheathing edge and into the gutter. Its absence allows capillary action to pull water back onto the roof edge assembly, causing sheathing and fascia deterioration.

Water Curls Without a Lip. Surface tension pulls runoff back under the shingle unless a metal edge throws it clear.

Look for the evidence rather than only the absence — soft or stained fascia, delaminated sheathing edge visible from the attic, or paint failing on the fascia's top edge.

• •Treating drip edge as a wind-resistance component
• •Assuming a functioning gutter makes drip edge unnecessary
• •Reporting the absence without looking for fascia and sheathing damage