Daylight visible through the attic boards - Free Estimate, One Written Price

What’s Happening

Daylight visible through your attic boards almost always means your roof deck has open gaps – either from missing or displaced shingles, failed flashing, or rotted decking boards that have separated. This is an active breach, not a cosmetic issue. Rain, wind, and pests have the same clear path inside that the light does.

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What you’re seeing from below is the roof’s underlayer – sometimes called the decking or sheathing – showing daylight because whatever was sealed above it is no longer doing its job. That could be a missing shingle, a cracked ridge cap, a section of flashing that’s pulled away from a chimney or vent, or a board that’s actually rotted through. Each cause has a slightly different fix, but every single one of them needs to be addressed before the next rain. A gap in your roof doesn’t stay a small problem for long.

Why It Happens

Missing or Blown-Off Shingles

Wind gets under shingle tabs over time, especially if the adhesive seal strip has dried out or the nails were driven too high during the original install. Once a tab lifts, the next windstorm can take the whole shingle with it. From the attic, this looks like a small or large patch of bright, clear light – often rectangular – right where the shingle used to sit. From the ground, you may see a bald or discolored patch on the slope.

Deteriorated or Separated Flashing

Flashing is the metal sheeting that seals the joints between your roof and anything that interrupts it – chimneys, skylights, vent pipes, dormers, roof-to-wall connections. It’s almost always the first thing to fail on an older roof, because it expands and contracts with temperature more dramatically than the shingles around it. In the attic, daylight from a flashing failure typically appears as a thin line or crescent of light right at the base of a chimney or around a vent collar rather than an open rectangular patch.

Rotted or Damaged Roof Decking

The decking – the plywood or OSB panels nailed to your rafters – can rot from the inside out when moisture gets trapped beneath the shingles for long enough. A rot failure often smells damp or musty before it shows daylight; the wood gets soft and eventually separates or collapses slightly. If the light you’re seeing comes with a spongy or discolored spot on the underside of the decking, rot is very likely the cause. This is also the scenario where an old, overzealous DIY patch job tends to make itself known – sealing the surface without drying out what’s underneath.

Failed Ridge Cap or Hip Shingles

The very peak of your roof – the ridge – is covered by a row of specially shaped cap shingles. These take more direct UV exposure and wind stress than any other part of the roof, so they tend to crack, curl, and fail earlier. When a ridge cap shingle is gone, the gap runs right along the top of the roof and daylight can be visible from multiple points along the attic’s peak. You may also hear a faint whistle or hum when wind is blowing, because air is moving through the gap.

What to Do Right Now

• Stay out of the attic if any boards feel soft underfoot. Rotted decking can give way under body weight. Take your photos from the hatch or the attic stairs and stop there.
• Photograph the light source from below. Get as many angles as you safely can – where exactly the light enters, how wide it looks, whether it’s a clean opening or a ragged edge. These photos will help your technician know exactly what they’re walking into before they get on the roof.
• Move anything stored under the gap. Boxes, furniture, insulation batt – get it away from the area directly below the breach. If rain comes before the repair is done, you want as little in the damage zone as possible.
• Note any water stains on the rafters or decking nearby. Water doesn’t always drip straight down. It runs along wood grain and pooling, so stains three feet from the gap can still tell the story of how long this has been happening.
• Do not attempt to seal or patch the gap from the roof side yourself. Working at height on a damaged deck is genuinely dangerous, and a temporary patch applied without full access to the flashing or decking below can trap moisture and make the repair harder. Call your local Mercer Roofing team and let a technician get up there properly equipped.

How We Fix It

When your local Mercer Roofing technician arrives, they’ll do a full inspection of both the attic and the exterior roof surface – not just the spot where light is visible. Gaps often have secondary water intrusion paths nearby that aren’t obvious from one angle. The technician will identify the exact cause, check the decking condition beneath, and look at the surrounding shingles and flashing for anything that’s close to failing.

From there, you get a written price – in full, before any work starts. That’s not a policy we bend; it’s how every job works at Mercer Roofing. If the job involves replacing shingles, we work with manufacturer-recognized brands including GAF, CertainTeed, Owens Corning, IKO, Atlas, Tamko, and Boral, and we’ll match your existing roof as closely as possible. Flashing repairs and decking replacement are handled in the same visit when the scope allows.

Most single-breach repairs are completed the same day the inspection is done. Every repair comes with a written guarantee and our 365-Day Done Right Promise – if the repair fails within a year, we come back and make it right, at no additional cost. This falls under our Roof Repair service, and in cases of significant decking damage, your technician may discuss a broader Roof Installation scope if warranted.

Frequently Asked Questions

Get It Fixed

Call (743) 200-8347 – a real person picks up, any time – and your local Mercer Roofing team will schedule an inspection, put a written price in your hands before anything starts, and get your roof sealed up right. The 365-Day Done Right Promise covers every repair we make.

Written by Grant Whitlock, Owner at Mercer Roofing, part of the Threshold Group family of home-service companies serving communities nationwide since 2000.