Evaluating & Replacing Older Skylights
Evaluating & Replacing Older Skylights
A major source of hidden water damage. Discover the hail hazards of original 1990s acrylic domes, flashing failures, and replacement costs from a local residential builder and engineer.
The Hazard of 1990s Acrylic Domes
Vaulted ceilings and abundant natural light were massive architectural trends in Highlands Ranch during the 1980s and 1990s. To achieve this, builders installed thousands of acrylic "bubble" dome skylights. While they look retro, they represent a significant structural liability today.
After three decades of exposure to Colorado's intense, high-altitude ultraviolet light, these plastic domes become incredibly brittle. During our severe spring hail storms, the compromised acrylic can easily shatter. When a skylight shatters during a thunderstorm, the resulting interior water damage to your drywall, hardwood floors, and electrical systems is catastrophic. Upgrading to modern, impact-resistant flat glass units (like Velux) is a mandatory step for protecting your investment.
The Engineer's Warning: Flashing Failures
If you see water stains on the drywall surrounding a skylight tunnel, do not let a seller tell you they "just need to re-caulk it." Caulk is a temporary band-aid. True leaks are caused by the failure of the metal step-flashing woven into the roof shingles around the unit. The aluminum flashing corrodes or separates over 30 years. The only correct, engineer-approved fix is to completely remove the old skylight, strip the surrounding shingles, install new ice-and-water shield, and integrate a brand new unit with modern, continuous factory flashing.
Seal Failures & Replacement Costs
Another common issue in vintage homes is "foggy" skylights. This condensation indicates that the thermal seal separating the dual panes has completely failed. Once the seal breaks, the insulating properties (R-value) vanish, causing your HVAC system to work overtime to heat or cool the room.
If you are purchasing a home with original skylights, you must budget for their imminent replacement. Depending on the pitch of the roof and the size of the unit, replacing an old dome with a modern, low-E energy-efficient flat glass skylight typically costs between $1,500 and $3,000 per unit. As your real estate advisor, we aggressively identify these failing units during our walkthroughs to negotiate these hard replacement costs into the initial purchase price.