So how do you know whether the problem you're experiencing is tied to your skylight or roof?
Keith Fackrell, who specializes in skylight installation as owner of Mastercraft Builders in Redwood City, has a simple test to address that concern. Cover your skylight with a tarp, and then wrap some rope around the tarp, securing it to the skylight. Then pour water over the tarp (or wait for rain). If water continues to enter the house, you have a roof leak. If not, then it's likely a skylight issue.
There are three main types of skylights: tubular, fixed, and ventilating. Tubular skylights are great solutions for adding daylight to small, enclosed spaces, such as hallways and closets, and for funneling light, commonly as ten- or 14-inch diameter round openings, down into the interior of the house.
Fixed skylights are used in rooms that need additional light but do not require additional ventilation.
Ventilating skylights are used in any rooms that need both additional light and venting, especially kitchens, bathrooms, and laundry rooms. They come in manual and electronically operable versions. The electronic versions eliminate the hassle of having to crank open the skylight when fresh air is needed. Moisture sensors on electronic skylights close the window automatically when it starts to rain so that the room stays dry even if you're not home to close it.
Unfortunately, California building codes specify that operable skylights can not be installed closer than ten feet from a plumbing vent, such as toilets or sinks, because such skylights could return sewer gasses back into the house. To work around this, Fackrell sometimes recommends that homeowners extend the plumbing vents ten feet away and ten feet higher than the window. "You take a pipe and slip it over the existing one," he says.
Skylights are comprised of several components. The most visual part is the glazing, also called the lens. Made of glass, or plastics such as acrylic or polycarbonate, they can be a single layer or multiple layers. The glazing is supported by a frame and attached with cladding. The curb that the skylight sits on raises it above the roof.
Original Eichler skylights were a unique size: 19 by 19 inches. Today, you can get 22.5 by 22.5 skylights off the shelf at most home centers, but these larger skylights won't properly fit over the smaller opening.
"I get homeowners all the time who have big [poor-fitting] skylights that are causing issues. They can leak or cause condensation, and I've seen them blow off the roof in heavy wind when installation isn't done properly," says Rick Abril of Abril Roofing, Bay Area Eichler specialists in foam roofing.
Most California skylight installers for flat and low-pitched modern homes primarily look to three major skylight manufacturers for their projects: Royalite, Velux, and Sunoptics.
For those who want a design similar to the original Eichler skylights, Royalite may be a good fit. The company manufactures domed acrylic skylights that have two layers of acrylic to help reduce condensation. Choose from a clear, white, or bronze dome.
The clear acrylic brings in the most heat and light, but it concentrates that light in one spot. "If you put this clear skylight in a bathroom, it can make it difficult to put on makeup, for instance, because it causes a glare and reflects a lot of light in your mirror," Fackrell says.
The white acrylic dome, on the other hand, lets in a diffused light that doesn't cast shadows around the room. "Most of the skylights I install are white because it gives a nice light—but you can't see the stars or the clouds in the sky with these skylights," he says.
Velux, considered the largest skylight manufacturer in the world, makes flat glass skylights. They have metal frames that are vinyl clad, which helps to reduce condensation on the frame. The company offers skylights of clear, white, or tinted glass that fit over the existing curb.