Water stains on a ceiling under the eave get blamed on the roof almost every time. Sometimes the roof is the cause. Sometimes the water came through a recessed light set into the soffit above, where the housing was never sealed to the board and rain runs along the top of the soffit until it finds the gap. The two faults look alike from the ground and from inside the room, so the first job is to tell them apart before anyone pulls shingles.
Leak and repair
A recessed soffit light is a metal or plastic can pushed up into a hole cut in the soffit panel. The trim ring sits on the outside, the can sits in the eave space, and the wire runs up to the house wiring. On many St. Louis houses the soffit is vented aluminum or vinyl, and the fixture hole is often cut with a hole saw and left with raw edges. Water that reaches the top of the soffit panel does not drip straight down. It runs back along the panel toward the wall, and at the fixture it finds the gap between the trim ring and the panel, the gap around the can, or the gap where the wire enters the housing.
Several things make this worse. Freeze and thaw cycles push a fixture ring slightly out of plane each winter, so a bead of caulk that held in the first season can open by the third. Wind-driven rain tends to hit the windward side of the house first, so the fixture on that side often leaks first. Pressure-washing the eave forces water into the hole, which is why a leak can start a week after a clean-up. None of these is a shingle fault, and a new shingle course laid over the eave will not stop water that enters from below the roof plane.
Start with the ceiling. Find the stain, then look at the ceiling directly above it and at the wall below the eave. A stain that lines up with a fixture on the other side of the wall, or that is wettest right under the light, points at the fixture. A stain that sits high up the rake, or that stops at the top of a dormer wall, points elsewhere, and the roof leak guidance elsewhere on this site applies. The stain alone is not enough. Water travels along rafters and sheathing before it shows, so the ceiling spot can be several feet from the place where the water entered.
Next, look at the soffit from the ground with a flashlight held at a low angle. Dark rings, rust-colored streaks or swelling on the soffit panel around a trim ring show a repeated wet cycle. Check the fascia just beyond the fixture too. If the fascia is soft or the paint is blistered in a line below the light, water has been running that path for a while. Do not probe the fixture or the soffit near any wiring until the circuit is shut off at the panel.
Telling a fixture leak from a roof leak
A roof leak under the eave usually shows as a stain that grows after a hard rain from the roof side, often near a valley, a flashing or a shingle course that has lifted. A soffit fixture leak tends to show after wind-driven rain or after the eave is wet from the outside, even when the roof above is dry. The simplest test is a garden hose on a dry day. Wet the soffit around the fixture for two or three minutes, then check the ceiling below. Work from the bottom of the eave upward, one section at a time, so you know which spot was wet. If the stain appears within minutes of the water hitting the fixture, you have your answer. If nothing happens, return to the roof.
Keep the test short and written down. Note the time, the section wetted and what you saw. A dated photo sequence is worth more than a memory of what the ceiling looked like last week.
What it costs
The repair is usually small, but the trip to the eave is what the bill pays for. A fixture repair means shutting power at the breaker, opening the soffit panel or working through the fixture housing, replacing or resealing the trim ring with a product rated for exterior use, and checking the wire where it enters the can. If the wiring is brittle, if the fixture is an older unsealed type, or if the wet wood needs replacing, the work grows. Ask whether the price includes a licensed electrician for the wiring, or whether the roofer is doing only the exterior seal. Those are different scopes, and they are not interchangeable.
If the fascia or soffit board has rotted near the fixture, price the wood as a separate line. Rot is usually found once the panel is open, and an allowance line in the bid that reads "rot replaced at unit price" is more honest than a guess made from the ground. The same goes for the ceiling drywall below the eave, which often needs cutting back to dry board after repeated wetting. That repair belongs in the bid as its own item, not inside the roof price.
What to ask
Before you agree to anything on an eave light, ask these questions of whoever comes out:
- Which fixture is leaking, and how was that confirmed on the day with a water test?
- Who shuts off and tests the circuit, and is that person licensed for the wiring?
- Is the fixture rated for exterior and wet locations, and will it be replaced or only resealed?
- What sealant is used at the trim ring, and what is its rated temperature range for a St. Louis winter?
- Is the soffit panel being opened, and will the cut edges be sealed or closed back up?
- What happens to the fascia and drywall if they are wet, and is that work priced separately?
- Will the crew photograph the open soffit and the fixture before and after the work?
If you want the eave looked at, call the Keys Roofing office at (314) 220-2333. The crew will document what they find and leave a written scope with photos and measurements for you to keep.