Help! My Skylight Leaks When It Rains

November 12, 2021

A skylight can be one of the most important features a home has since it can turn a room that might otherwise seem dark and dreary into a bright and cheerful space. It’s also one of the more vulnerable areas in the home, as it has several weak spots that rain can slip through if they happen to become compromised.

Skylights are also sometimes installed incorrectly, which can also lead to leakage. If your skylight leaks when it rains, this can lead to catastrophic damage inside the home. It can create unsightly dark spots on the ceiling, cause the wood floor to warp, and destroy property that it drips onto. If your home is experiencing a leaky skylight, here’s what you can do.

Figure Out What’s Leaking

While the individual parts that make up your skylight are probably all made from very strong, sturdy materials, they can still be vulnerable where these parts connect. That said, if you notice a leak, there are several parts of the skylight that are likely to be the culprits.

The Lens

The frame of the skylight holds the lenses together. A silicone sealant is usually used to connect these parts together and to form a watertight seal. Over time, however, the relentless assault of wind, rain, and other inclement weather can damage this seal. Even a small crack in the sealant between the lenses and the frame can allow water to make its way inside your home.

The Skylight Flashing

The flashing on your roof is thin and lightweight but serves a critical function: it redirects rain away from more vulnerable areas of your roof. Made from thin metal, you’ll notice flashing protecting areas of the roof such as the chimney and any valleys from the rain. This flashing is also installed around the skylight, and as long as it’s properly installed and remains in good condition, it will do an excellent job to keep water out of your home. However, if it becomes damaged by the weather, or if the metal begins to rust, it may begin to let the water in.
Other areas can develop leaks as well, and you’ll have to work to discover exactly where those leaks are coming from.

Locating the Source of the Leak

The easiest way to locate the source of a leaking skylight is to do a hose test. This is a two-person job: one must remain in the home, underneath the skylight, with a bucket. The other must spray the top of the skylight with a garden hose. Eventually, if a leak is present, the person inside the home should be able to see water droplets begin to form. This is the spot where the leak is.

You may also notice that there are several leaky areas. If that’s the case, you’ll need to fix them all before you can guarantee there won’t be any water damage inside your home every time a rainstorm blows through.

On occasion, you may notice water damage, and yet the garden hose will not yield any evidence of leakage. In this case, the leak may actually be caused by condensation. As skylights are in a higher part of the home, the temperature differences between the room, the outside, and the skylight itself can lead to water droplets forming on the glass. These will then drip without any obvious signs of a leak.

Fixing a Leaky Skylight

If your skylight leaks when it rains, the first step toward addressing the problem is to thoroughly clean it. Often, a buildup of dirt and debris can actually become the cause of a leak, for several reasons. Twigs, sticks, and branches can damage both the glass and the seal around it, leading to leaks. They can also become stuck between the frames holding the skylight together, allowing water inside. Sometimes, repairing your skylight is as simple as clearing it of twigs and branches.

The next step is to replace the damaged sealant. Waterproof silicone sealants can be purchased in most hardware stores. Install sealant over damaged areas, ensuring that the leaky area is thoroughly covered. In some cases, you’ll have to peel away some of the original sealant and replace it entirely.

If the cause of the leak is due to damaged flashing, you will have to replace the offending material. This can be a difficult job, not to mention a safety concern if you are not careful. If you need to climb onto the roof to repair some flashing, make sure you have all the proper safety gear for working with the tools. This means gloves, closed-toe boots, and eye protection (as well as fall protection equipment, of course). Carefully use a roofing hammer to pry away the damaged flashing. You can then replace it by nailing down new flashing made from aluminum or another durable material.

As we’ve mentioned, it’s also possible the source of the leak is actually condensation. If this is the case, then adding silicone sealant or replacing the flashing will not help. Your best option in the case of condensation is to improve the ventilation in your home and consider investing in a dehumidifier.

If the Problem Continues

If you can’t seem to solve the problem on your own, or if personally replacing flashing and climbing around on the roof is not something you wish to do, you can also contact a professional from Interstate Roofing. We specialize in the installation and repair of skylights, as well as other roofing features.

When a skylight leaks when it rains, in many cases, the problem is caused by improper installation. That’s why it’s important to avoid the problem entirely by securing the services of experienced professionals to perform the installation for you, and Interstate Roofing certainly fits the bill. We are also able to perform maintenance and repairs, no matter how severe the leak is or how extensive the damage that has already taken place is.