Identifying the Most Common Causes of Skylight Leaks and How They Affect Long-Term Roof Performance

For property owners, understanding the root causes of a commercial skylight curb leak in Modesto and how leaks progress is essential for protecting long-term roof performance. This overview from Peterson Roofing explains the typical failure points, the potential impact on your roofing system, and practical steps to prevent costly damage.

• Improper curb flashing and flashing integration: The junction where the skylight meets the roof is the primary water barrier. If the curb flashing isn’t installed or maintained correctly, water can migrate under the roofing membrane.
• Deteriorated sealants around the curb: Weathering, UV exposure, and temperature cycling can crack or degrade exterior sealants, creating a path for moisture to reach the interior structure.
• Damaged or aged roofing membrane near the skylight: If the membrane around the skylight is torn, punctured, or has degraded adhesive, water can bypass the curb and travel along the membrane.
• Inadequate curb height or misaligned flashing: If the curb is too low or the flashing doesn’t properly shed water away from the skylight, moisture can pool and penetrate.
• Ponding water and drainage issues: Flat or low-slope sections around a skylight can accumulate water. Prolonged ponding increases the chance of seepage through joints and fasteners.
• Weather damage and wind uplift: Severe rain, hail, or wind-driven moisture can compromise flashing, seals, and the skylight itself, initiating leaks even in newer installations.
• Roof aging and movement: Over time, roof decking, fasteners, and sealants expand and contract with temperature changes, which can loosen connections and create new leak pathways.

• Water intrusion reaches decking and insulation: Continuous moisture accelerates wood decay, warping, and insulation saturation, reducing energy efficiency and comfort.
• Mold and microbial growth: Hidden leaks foster mold growth, affecting indoor air quality and potentially triggering health concerns for occupants.
• Degraded underlayment and fasteners: Repeated exposure weakens the roof assembly, increasing the risk of more extensive, harder-to-repair damage.
• Energy losses and higher costs: Wet or damaged insulation loses R-value, raising heating and cooling costs over the life of the roof.
• Structural and surface deterioration: Prolonged leaks can lead to rot, corrosion of metal components, and cosmetic deterioration that reduces property value.

• Schedule regular inspections: Conduct professional roof and skylight inspections at least once or twice a year, and after major storms, to catch early signs of wear.
• Prioritize proper installation and materials: Ensure skylight curb flashing, sealants, and roofing membranes are compatible and installed to factory standards.
• Maintain clean drainage around skylights: Keep gutters, scuppers, and surrounding roof surfaces clear to prevent water pooling near the curb.
• Address aging components promptly: Replace degraded sealants and damaged flashing promptly to halt the progression of corrosion and water intrusion.
• Consider design fixes for drainage: If a skylight location routinely gathers water, discuss with a qualified roofer about slope improvements or secondary drainage options.
• Document and monitor issues: Keep records of prior leaks, repairs, and inspections to guide future maintenance decisions.

If you notice active dripping, ceiling stains, soft decking, or musty odors near a skylight, contact a qualified contractor promptly. A professional assessment can determine whether the issue is a curb flashing, sealant, or membrane problem and outline a targeted repair plan. If you suspect a commercial skylight curb leak in Modesto or see signs of water intrusion, schedule an evaluation with a trusted roofer to prevent further damage.

Peterson Roofing serves commercial clients in Modesto with roof inspections, skylight sealing, and curb flashing repairs. Their team can assess skylight performance, identify leak sources, and recommend cost-effective strategies to maintain long-term roof integrity.

Take action today: if you’re facing a suspected commercial skylight curb leak Modesto, contact Peterson Roofing for a professional inspection and a clear plan to protect your building’s roof performance. Regular maintenance and timely repairs are the best defense against costly moisture damage and degraded energy efficiency.