Skylight Leaks: Flashing is the Culprit
Skylight flashing is designed to make an adjustment between the sloped roofing and the skylight curbs. Done right, and as part of a correctly installed roofing system, skylight flashing allows you to enjoy your skylight for many years. Done wrong, you can end up with leaks that can utterly ruin the room below the skylight.
Skylight Flashing is Critical
Many contractors don’t understand the importance of skylight flashing; they tend to see tar and underlayments as the primary methods of protecting against leaks. In reality, your skylight flashing must be properly installed if you want a water-shedding system that will last for years to come.
How Can You Spot a Poor Installations?
If you want to ensure your contractor has done a good enough job to prevent skylight leaks from occurring, look for the following:
- All pieces of flashing extend 4 inches from the skylight onto the roof deck.
- There is a back pan exit that prevents water and snow from accumulating in the back pan.
Should You Re-flash to Prevent a Leaking Skylight When You Re-roof?
Re-flashing skylights is an added expense when you have a new roof put on, but it is well worth the money. Here’s why:
- The old flashing may be rusted.
- The old flashing may be crumpled in the roof removal process.
- The old flashing will have nail holes from the previous installation.
- Water can enter through these holes.
- The old flashing may have been incorrectly installed in the first place.
- There is no way the old flashing will have the same life expectancy as the new roofing material. To prevent skylight leaks, it will have to be replaced before your new roof will have to be replaced.
Training is Key for Skylight Flashing
Because skylight flashing is such an integral part of your roofing system, it should always be installed by someone with technical experience and hands-on knowledge. This experience and knowledge should extend to an awareness of the issues related to tying skylight flashing into a variety of exterior finishes, including wood, stucco and vinyl.
It should be noted that the Alberta Building Code does not cover skylight flashing. This has resulted in a lack of proper training in the installation of skylight flashing.