A leak at the rake edge of a gable roof often shows up on a day when the rain was not falling straight down. The water comes sideways on the wind, climbs under the last shingle at the edge, and runs along the underlayment until it finds a nail hole or a gap in the drip edge. By the time it reaches the ceiling, the stain may sit well away from the wall where the water got in. If you are standing in a bedroom in St. Louis County with a brown ring on the drywall near the gable wall, this page covers the next decision you have to make.
Why the rake edge takes wind-driven rain
Rain on a gable roof mostly runs down the slope and off the eave, but the rake is the sloped edge that meets the wall. Wind pushing from the west or south hits that edge at an angle and drives water up under the overhang. The shingles at the rake are cut to a line, and the exposed edge of the last course is where a small lift is enough to let moisture in. Storms that cross the metro from the southwest often bring rain at a sharp angle for an hour or more, long enough for water to soak into the felt beneath.
Roofers call the metal along the edge the rake drip edge. Its job is to carry water past the underlayment and out over the gutter line without letting it wick back under. When that metal is installed with its leg too short, or when the underlayment is lapped the wrong way, wind can push water up past the lip. Nails that run through the metal and into the rafter tail can also loosen after several winters of freezing and thawing, opening a path the water finds on the next gusty night.
How it differs from a leak higher up
A leak from the ridge or from a valley usually shows its stain close to where the water entered, because gravity pulls it down a fairly predictable line. A rake leak does not work that way. Water can travel a long distance along the top of the decking and the underside of the sheathing before it drips. The stain can appear several feet from the gable wall, near a window or in the middle of a closet ceiling, and it may only appear during wind-driven rain. A dry week can make the spot look healed, which is why people often stop watching it.
Some quick checks help separate the rake edge from the rest of the roof. Go into the attic on a rainy day or just after a storm with a flashlight. Look at the underside of the gable end sheathing and the tops of the rafter tails near the wall. Dark staining along the edge boards, wet insulation pressed against the gable wall, or drip marks on the framing that run parallel to the rake all suggest the edge is taking water. If the wet line forms a V that runs up toward the ridge, the source is more likely in the field of the roof or in a valley, and that calls for a different repair.
What a proper repair looks like
A patch of caulk at the edge is not a repair. Caulk sits on top of a shingle that is designed to shed water by lapping, and it cracks within a season or two under the expansion and contraction of St. Louis summers and winters. A real fix starts by lifting the course of shingles above the edge, checking the underlayment and the drip edge for correct lap direction, and replacing any nails that have backed out. The metal may need to be reset so its top leg sits under the underlayment and its bottom leg hangs over the gutter line. Where the rafter tail is soft from years of water exposure, the damaged wood needs to come out before new metal goes on.
Keys Roofing installs Atlas and Malarkey shingles, and the shingles used at the rake should meet the same spec as the rest of the field. If the repair involves lifting shingles, the crew should document the condition of the underlayment before it goes back down, with photos and measurements of the edge, the drip metal and the rafter tails. A written scope that says which pieces were replaced and which were reset is the record to keep, whatever happens afterward.
What to ask the roofer before the work starts
Ask the roofer to show you the rake edge from the ground and from the attic before anyone climbs. Ask whether they plan to reset the drip edge, replace it, or add a layer of underlayment at the rake. Ask how they will protect the gable wall and the gutter during the work, because a crew that lifts shingles at the edge will drop debris, and sometimes leaves a gap for the next rain if the job is not closed in the same day.
Ask what will be done about the rafter tail if it is soft. A tail that has been wet for years can look sound from the outside while the end grain has broken down. If the roofer says the wood is sound, ask for a photo of the cut end or a probe test with a screwdriver, recorded in the scope. Ask for the scope in writing, with the photos and measurements attached, before you sign anything.
Timing the repair and checking it after rain
A rake repair should be checked after the next wind-driven rain, not just after the first light shower. Wait for a storm with a strong sideways wind, then look at the attic underside within a few hours. If the wet line is back on the edge boards, the repair did not reach the water path, and the roofer needs to see it. Keep a note of the date, the wind direction and the rainfall so the record is clear if the problem returns.
Cold weather adds another step. In winter, the rake edge can carry ice that builds up in the gutter and pushes water back under the lower course. Clearing the gutter at the gable end before a hard freeze lowers the chance of that happening, and a roofer who sees ice in the gutter at the rake should note it in the scope. If the leak returns after a freeze, the cause is often the same edge detail as before, not a new leak somewhere else.
When to call
If the stain is spreading, if the ceiling feels soft, or if water is reaching a light fixture, get a roofer on the roof soon. Until then, move valuables away from the wall, put a bucket under the drip, and take photos of the stain and the attic before anything is cleaned. The office number for Roof Leak Repair St. Louis is (314) 220-2333. Ask for a site visit that checks the rake edge both in wind and in dry weather, and ask that the findings come to you in writing with the photos attached.