Most roof problems don't announce themselves with a dramatic leak in the middle of your living room. They start small — a few missing granules here, a subtle dip in the roofline there. By the time water is dripping through your ceiling, you've likely got thousands of dollars in structural damage that could have been prevented.
Charlotte's climate is particularly hard on roofs. We get intense UV exposure from May through September, heavy thunderstorms, occasional hail, and enough humidity to encourage mold and algae growth year-round. These five warning signs are the ones I see most often on Charlotte homes, and each one tells a specific story about what's going wrong up there.
1. Missing, Cracked, or Curling Shingles
Urgency: High — address within 1 to 2 weeks
This is the most visible sign, and the one homeowners spot first. Walk to the end of your driveway and look at your roof from the street. What you're looking for:
- Missing shingles: Dark patches where shingles have blown off completely. You might find them in the yard or wedged in the gutter.
- Cracked shingles: Visible splits or fractures. These typically run vertically and happen when shingles lose flexibility as they age.
- Curling edges: Shingle corners or edges that are lifting up, turning inward (cupping), or bowing upward (clawing).
Here's what each one means. Missing shingles leave your roof deck exposed to rain, and it only takes one heavy storm to drive water into the underlayment and decking beneath. This is a repair you should schedule within a week or two — not something to put off until next month.
Cracking usually means the shingle has reached the end of its useful life. The asphalt has dried out and become brittle. If you see cracking on a few shingles in one area, a spot repair works. If cracking is widespread across the roof, you're looking at a replacement — the shingles are telling you they're done.
Curling is the one that worries me most because it's progressive. Once a shingle starts curling, it catches wind more easily, which peels it further, which lets water underneath. In Charlotte's thunderstorm season, one bad storm can rip curling shingles off in sheets. If more than 20% of your shingles are curling, it's time to start getting replacement quotes from Charlotte roofers.
2. Granules Piling Up in Your Gutters
Urgency: Medium to High — get an inspection within the month
Next time you clean your gutters — or next time it rains hard — look at what's coming out of your downspouts. If you see a gritty, sandy residue that looks like coarse black or brown sand, those are shingle granules. And they shouldn't be there in large quantities.
Asphalt shingles are covered with ceramic granules that serve two purposes: they protect the asphalt from UV radiation, and they give the shingle its color and fire resistance. When those granules start falling off, the bare asphalt underneath is exposed to direct sunlight. In Charlotte's summer heat, exposed asphalt deteriorates fast — we're talking months, not years.
Some granule loss is normal in the first year after installation — that's just loose manufacturing residue washing off. But if your roof is 10+ years old and you're seeing heavy granule accumulation in the gutters, splash blocks, or pooling at the base of your downspouts, your shingles are losing their protective layer.
You can also spot granule loss from the ground. Look at your roof in direct sunlight. Shingles that have lost significant granules will look darker and shinier than the surrounding shingles — you're seeing the exposed asphalt reflecting light differently. This is a great reason to schedule a professional roof inspection to get an honest assessment of how much life your roof has left.
Exception: if you see sudden, heavy granule loss right after a storm, that's hail damage, not aging. That's an insurance claim situation, and you should document it immediately.
3. A Sagging Roofline
Urgency: Very High — call a roofer today
Stand across the street from your house and look at your roofline — the ridge at the very top and the edges along the eaves. Both should be straight. If you see any dipping, bowing, or waviness in the roofline, you have a serious structural problem.
A sagging roof means one of three things:
- The roof decking (plywood or OSB) is rotting. Water has been getting through the shingles and underlayment for a while, soaking the wood underneath. Wet plywood loses its structural integrity and sags under the weight of the roofing materials above it.
- The rafters or trusses are compromised. Either from long-term moisture damage, termites, or they were undersized for the span in the first place. This is more common in older Charlotte homes built before modern building codes.
- Too many layers of shingles. Some older homes in Matthews, Indian Trail, and other established neighborhoods have had new shingles layered over old ones — sometimes two or three times. All that weight can cause the decking to sag over time.
This is the one warning sign where I tell people not to wait. A sagging roof can fail — meaning a partial or full collapse — especially under the weight of heavy rain or if we get an unusual snow load. Get a roofer out to look at it as soon as possible. If the sag is pronounced (more than a couple inches over a span of several feet), some roofers will treat it as an emergency call.
The repair here almost always means a full tear-off to replace damaged decking and potentially reinforce or replace structural members. It's expensive — $15,000 to $25,000 or more depending on the extent — but ignoring it risks a much more expensive and dangerous outcome.
4. Daylight Visible Through the Roof Boards
Urgency: High — address within 1 to 2 weeks
Here's a test anyone can do. On a sunny day, go up into your attic. Turn off any lights and let your eyes adjust. Now look up at the underside of the roof deck. Do you see any pinpoints of light coming through? If so, those are holes. And if light can get through, water is getting through too.
While you're up there, look for these additional signs:
- Dark stains or streaks on the underside of the decking: This is water damage. The wood has gotten wet repeatedly.
- Mold or mildew smell: Charlotte's humidity means any moisture in the attic quickly becomes a mold problem.
- Wet insulation: If your fiberglass or blown-in insulation is damp or matted down, water is coming in from above.
- Rusty nail heads: Nails poking through the decking that show rust have been exposed to moisture condensation — a sign of poor ventilation, which accelerates all other roof problems.
The most common cause of daylight through the roof deck is failed or missing flashing around pipes, vents, chimneys, and skylights. Flashing is the metal (usually aluminum or galvanized steel) that seals the gaps where something penetrates the roof surface. Over time, flashing can rust, crack, or pull away from the surface. Charlotte's temperature swings — from 95-degree summer days to 25-degree winter nights — cause metal to expand and contract constantly, which loosens sealants and creates gaps.
If the issue is isolated to a few penetration points, flashing repair is relatively affordable — $200 to $600 per penetration. If the daylight is coming through the decking itself (not at a penetration point), that's a bigger problem indicating cracked or missing decking, and you're looking at a partial or full roof replacement.
5. Moss, Algae, or Dark Streaks Covering the Roof
Urgency: Medium — address within 1 to 3 months
If your Charlotte home has a north-facing slope or sits under heavy tree cover, you've probably noticed dark streaks, green patches, or fuzzy moss growing on the shingles. This is extremely common in our climate — Charlotte's combination of heat, humidity, and shade creates ideal conditions for biological growth on roofs.
Each one is different, and the fix depends on what you're dealing with:
Dark streaks (Gloeocapsa magma algae): Those black or dark brown streaks running down the roof are actually a type of blue-green algae. It feeds on the limestone filler in asphalt shingles. While it looks terrible, algae alone doesn't cause immediate structural damage. But it does two things: it holds moisture against the shingle surface (which accelerates aging), and it makes your roof absorb more heat (because the dark streaks reduce reflectivity). Over time, this shortens shingle lifespan by several years.
Green patches (moss): Moss is the bigger concern. Unlike algae, which sits on the surface, moss sends root-like structures (rhizoids) into the shingle material. It lifts shingle edges, traps moisture underneath, and creates channels for water to flow under the shingle rather than over it. Left unchecked for a few years, moss can cause genuine water damage to the decking.
What to do about it depends on how far it's progressed:
- Light algae streaking: A professional soft-wash treatment ($300 to $600 for a typical Charlotte home) removes the algae and prevents regrowth for 2 to 3 years. Never pressure wash asphalt shingles — the high pressure strips granules.
- Moderate moss growth: Moss needs to be killed first (with a moss-killing solution), then gently brushed off after it dries. Trim overhanging tree branches to let more sunlight reach the roof. Install zinc or copper strips along the ridge — when it rains, metal ions wash down the roof and inhibit regrowth.
- Heavy, long-term moss or algae with visible shingle damage underneath: At this point, the shingles may be compromised enough that cleaning won't fix the underlying damage. Time for an inspection to see whether repair or replacement makes more sense.
A lot of neighborhoods around Lake Norman, Mooresville, and Davidson have heavy tree canopy, and moss is an ongoing battle. If you're in a heavily wooded area, plan on having your roof soft-washed every 2 to 3 years as part of your regular roof maintenance routine.
What To Do If You Spot Any of These Signs
Here's the priority list:
- Sagging roofline — Call a roofer today. This is structural and potentially dangerous.
- Missing or cracked shingles — Schedule a repair within 1 to 2 weeks, sooner if rain is in the forecast.
- Daylight through the roof deck — Schedule an inspection and repair within 1 to 2 weeks.
- Heavy granule loss — Get an inspection within the month to assess remaining shingle life.
- Moss and algae — Address within 1 to 3 months. Not an emergency, but don't ignore it for years.
For any of these issues, the smart first step is a professional inspection. A good roofer will get on the roof, take photos, and give you an honest assessment — repair vs. replace, what it'll cost, and how urgent it is. Most reputable Charlotte roofing companies offer free inspections, so there's no financial risk in getting someone to look.
The biggest mistake I see Charlotte homeowners make is assuming a small problem will stay small. Roofs don't work that way. A $400 flashing repair today prevents a $4,000 ceiling repair next spring. A $12,000 replacement when the signs are clear prevents a $20,000 emergency replacement when the roof fails during a storm.
If you've noticed any of these warning signs, get a free quote from a local roofer and find out exactly where you stand.