Ice dams form along the roof edge when snow melts from the warm upper roof and refreezes at the cold eaves. The trapped water backs up under shingles, causing leaks into attic spaces, walls, and ceilings. Left untreated, ice dams cause extensive water damage, rotting fascia boards, and mold growth. A roofer can safely remove ice dams, install ice-and-water shield membrane, and improve attic ventilation to prevent recurrence.
Gutters overflowing in rain Gutters that overflow during rain are not directing water away from your foundation, which can lead to basement flooding, soil erosion, and foundation damage over time. The cause may be clogs from leaves and debris, sagging sections, undersized gutters, or damaged downspouts. A gutter specialist can clean, realign, or replace your gutter system to restore proper drainage and protect your home from water damage.
Leaking roof vent or flashing Leaks around roof vents, pipes, or flashing are one of the most common causes of roof leaks. Flashing — the thin metal strips that seal transitions between the roof and chimneys, vents, or walls — deteriorates over time from UV exposure, thermal cycling, and storms. Even a small gap lets water infiltrate into the attic and down through ceilings. A roofer can remove the old flashing, install new step or counter flashing, reseal vent boots, and verify there's no hidden water damage in the decking below.
Gutter sections that sag or pull away from the fascia board no longer channel water properly, causing overflow that erodes landscaping, stains siding, and can lead to foundation damage. Sagging is typically caused by loose or failed hangers, accumulated debris weight, ice damage, or rotted fascia. A roofer or gutter specialist can rehang the sections with properly spaced brackets, replace damaged hangers, repair fascia, and ensure correct slope for drainage.
Leaks at gutter joints and seams are the most common gutter failure. Sealant degrades over time, and thermal expansion widens gaps between sections. Leaking gutters pour water against the fascia, soffit, and foundation instead of channeling it away, causing rot and basement moisture. A gutter specialist can reseal joints, replace damaged sections, or install seamless gutters to eliminate joints entirely.
Moss thrives on north-facing or shaded roof surfaces where moisture lingers. While it looks harmless, moss roots work under shingle edges, lifting them and allowing water to penetrate the underlayment. Over time this leads to wood rot in the decking, leaks, and shortened roof lifespan. Pressure washing can damage shingles, so professional moss removal uses gentle chemical treatments, manual scraping, and zinc or copper strip installation to prevent regrowth. A roofer can assess the extent of damage, safely remove the moss, treat the surface, and recommend ongoing prevention.
Water entering around a chimney is one of the most common — and most damaging — roof leak sources. The leak usually originates from deteriorated flashing (the metal strips where the chimney meets the roof), a cracked chimney crown, damaged mortar joints, or a missing chimney cap. Because chimney leaks send water down hidden paths inside walls, the damage can progress for months before stains appear. A roofer handles flashing and roof-side repairs, while a mason addresses the chimney structure itself. Repair costs range from $200–$500 for reflashing to $1,000–$3,000 for crown and mortar rebuilds.
A leaking skylight can cause stained ceilings, rotted framing, mold growth, and damaged insulation if not addressed promptly. Not every drip is a true leak — condensation on the interior glass is common in winter when warm, humid indoor air meets the cold skylight surface, and it can look identical to a roof leak. A true leak usually appears during or shortly after rain and is caused by failed flashing around the skylight curb, dried or cracked sealant between the glass and frame, improperly installed step flashing where the skylight meets the shingles, or ice dams forcing water uphill under shingles. A roofer can diagnose the source with a water test. Re-sealing the skylight frame with appropriate roofing sealant costs $150–$400. Replacing deteriorated flashing around the curb — which requires removing surrounding shingles, installing new step and counter flashing, and re-shingling — runs $400–$1,200 depending on skylight size and roof pitch. If the skylight unit itself is cracked, fogged between panes, or over 20 years old, full replacement costs $800–$2,500 including the unit and installation. Deck-mounted skylights are easier to replace than curb-mounted ones. Adding a proper cricket (small diverter ridge) above a skylight on a low-slope section prevents future water pooling ($300–$600).
Standing water on a flat roof If water is still pooling on your flat roof 48 hours after the last rain, you have a ponding problem. Flat roofs are designed with a slight slope to drain, but sagging decking, clogged internal drains, or shifted insulation can create low spots where water sits. Prolonged ponding accelerates membrane deterioration, adds hundreds of pounds of dead load to the structure, and eventually causes leaks. A roofer can identify the cause — whether it's a drainage issue, structural deflection, or membrane failure — and restore proper drainage with tapered insulation, additional drains, or membrane repair.
Roof sheathing (the plywood or OSB boards nailed to the rafters beneath shingles) can rot when moisture becomes trapped — from a slow leak, poor attic ventilation, or ice dams pushing water under shingles. Soft, spongy spots on the roof surface, sagging between rafters visible from the attic, or dark water stains on sheathing boards are all signs of rot. A roofer can assess the extent of damage, replace affected sheathing panels ($70–$100 per sheet plus labor), and address the moisture source to prevent recurrence.
Mold in the attic usually signals a ventilation or moisture problem rather than a plumbing leak. The most common cause is inadequate soffit-to-ridge airflow: when warm, humid air from the living space rises and has no way out, it condenses on the cold underside of the roof sheathing and feeds mold colonies. Bathroom exhaust fans or dryer vents that terminate inside the attic instead of outdoors are another major culprit. Roof leaks — even small ones around flashing, valleys, or pipe boots — can also introduce enough moisture to start growth. Health-wise, attic mold can circulate spores into the HVAC system and living areas, aggravating allergies and respiratory conditions. A roofer or insulation specialist inspects ventilation pathways (soffit vents, ridge vent, gable vents), checks for exhaust fans venting into the attic, and evaluates roof integrity. If mold coverage is extensive (typically over 10 sq ft), a licensed mold remediation professional should handle removal before ventilation corrections are made.
Roof flashing pulling away Roof flashing is the thin metal strip that seals joints where the roof meets walls, chimneys, dormers, or vents. When it pulls away, lifts, or develops gaps, rainwater bypasses the shingles and runs directly into the roof deck, causing rot, mold, and interior water damage. A roofer removes the old sealant, re-bends or replaces the flashing, re-integrates it with the shingle courses, and applies fresh roofing cement to restore a watertight seal.
Ice dam forming on the roof An ice dam is a ridge of ice that forms along the eaves of a roof, preventing snowmelt from draining off. Heat escaping through the attic melts snow on the upper roof, and the water refreezes when it reaches the cold overhang. As the dam grows, water backs up behind it, seeps under shingles, and leaks into the attic, ceiling, and walls. Chronic ice dams signal inadequate attic insulation, poor ventilation, or air leaks from the living space into the attic. A roofer can install ice-and-water shield membrane on the vulnerable eave area, improve attic ventilation with ridge and soffit vents, and coordinate with an insulation contractor to seal bypasses that let warm air reach the roof deck.
Missing shingles after a storm High winds during a storm can lift, crack, or tear shingles completely off a roof, leaving the felt underlayment or bare deck exposed. Even a few missing shingles create an entry point for rainwater that can soak the roof deck, insulation, and ceiling below within a single rainstorm. The longer exposed sections remain unpatched, the greater the risk of mold growth in the attic sheathing and structural rot of the roof decking. A roofer can tarp the damaged area for immediate protection, then replace missing shingles with matching material, re-seal the flashing, and inspect the surrounding field for hidden wind damage such as lifted nail heads or cracked tabs that may fail in the next storm.
Gutters Pulling Away From the Fascia Board Gutters that are visibly separating from the fascia board, sagging between brackets, or pulling away at the mounting points are a problem that worsens with every rainstorm. The most common cause is the accumulated weight of water, wet leaves, and debris that overloads the hangers or spikes — especially when the gutters have not been cleaned in over a year. Rotted fascia wood is the second major culprit: the screws or nails lose their grip in softened wood, and the entire gutter section droops. In colder climates, ice dams can pry gutters away from the roofline overnight. A sagging or detached gutter directs rainwater against the foundation, erodes landscaping, stains siding, and can cause basement flooding or crawlspace moisture. A roofer can remove the old fasteners, repair or replace any rotted fascia sections, reinstall the gutter with heavy-duty hidden hangers spaced every 24 inches, verify proper slope toward the downspouts, and add gutter guards to reduce future debris buildup.
Soffit Damaged or Sagging Soffits — the panels covering the underside of your roof overhang — protect the attic from moisture, pests, and wind-driven rain. When they crack, warp, or begin sagging, they open a direct path for squirrels, raccoons, bats, and wasps to nest inside the attic or between rafters. Water also penetrates the gap, soaking the fascia board and rafter tails and accelerating rot that spreads to the roof sheathing above. Vinyl soffits crack from UV exposure and hail; aluminum soffits dent and separate at the joints; wood soffits rot when paint fails and moisture wicks in. A roofer experienced with soffit and fascia systems can remove the damaged sections, inspect the rafter tails for hidden rot, install replacement panels with proper ventilation slots, and seal the joints so the overhang is weathertight again.
Ice Dam Forming on Roof Edge An ice dam is a ridge of ice that builds up along the lower edge of a roof, blocking melting snow from draining into the gutters. As heat escaping from the living space warms the roof deck above, snow melts on the upper sections and flows downhill — but when it reaches the unheated eave overhang (which stays at or below freezing), the meltwater refreezes and accumulates into an ever-thickening ice barrier. Once the dam is tall enough, subsequent meltwater pools behind it and backs up under shingles, seeping through the roof deck into the attic, walls, and ceilings below. The telltale sign is icicles hanging from the gutter line combined with water stains appearing on interior ceilings or walls during or just after a cold spell. The root cause is almost always uneven roof temperature: insufficient attic insulation (allowing interior heat to escape), inadequate attic ventilation (trapping warm air at the ridge instead of flushing it out), and air leaks from the living space into the attic through recessed lights, bathroom fans, attic hatches, and top plates of interior walls. A roofer experienced with ice dam prevention can install ice-and-water shield membrane along the eaves (required by code for the first 24 inches in cold climates), add proper ridge-and-soffit ventilation to equalize roof temperature, and coordinate with an insulation contractor to seal attic air leaks and bring insulation to current code depth (R-49 in most cold zones per the IECC).