Dan's Papers - August 17, 2007 - Basking In the Skylight

Skylights can transform any room into the best room in the house. By introducing more natural light from one or more skylights, you can make the rooms feel more spacious, expansive and beautiful. In addition, the increase in natural light will help decrease your overall energy costs. Skylights that open up can also provide ventilation in rooms that may not be well ventilated. It is known that the benefits of natural light to people and houseplants are considerable. You might be surprised to know that skylights provide more natural light - up to 30% - than vertical windows. Many folks don't like the idea of cutting holes in their roof. But the truth is, adding a skylight is actually easier than installing a window. Most skylights come with flashing systems that will seal the roof effectively in order to avoid moisture from getting in.

There are two basic types of skylights - curb-mounted or frame-in-place. A curb-mounted skylight is raised above the plane of the roof and either sets on a wood frame curb or the curb is an integral part of the unit. A framed-in-place skylight is installed flush with the plane of the structure, much like a vertical window. It is held in place with L-shaped brackets. Both types of skylight are available in a variety of sizes that can be easily integrated into your ceiling and roof construction.

Skylights can be either "ventilating" or "fixed." Ventilating skylights are excellent for bath or kitchen. In addition to providing extra light, when opened, the overhead ventilation creates an updraft. Ventilated skylights can be operated by several means - temperature sensor, remote control, electric on/off wall switch or a manual or motorized hand crank. Fixed skylights are for additional light only. They're great for attics, bonus rooms or anywhere you want extra illumination. Styles and sizes vary from domes to rectangles. Acrylic skylights are available for utility rooms, workshops and garages where fashion is less of a concern than functionality.

Tubular skylights are relatively new on the scene. The small size - a 10-inch or 14-inch diameter - allows them to be used in spaces where full-sized skylights would be impractical. Hallways, bathrooms and even closets can accommodate a tubular skylight. They provide a lot of light in spite of their small size. The concept and installation process are basically the same for a regular skylight.

Some optional skylight features include insulted thermal glass, which prevents heat loss in winter and assists cooling in summer, tinting filter to protect from UV rays and additional heat, shades or blinds to screen out the sun, and insect screens on ventilating skylights to keep the bugs out.

Before you install a skylight, you need to be familiar with the roof and ceiling in your home. Make sure you know your roof support system when you go shopping. Support joists should be either 16" or 24" on center. The simplest installation occurs when the skylight fits between two roof joists. Skylights that are larger than the joist measurements can be installed but require reinforcing. Know what kind of roof you have. The roof thickness determines the type of mounting and flashing required. Thinner roofs like asphalt or fiberglass use self-flashing or curb mount. Thicker, high profile roofs such as wood shakes, slate or clay tile require built-up curb and flashing. Self-flashing is the prefabricated part of the unit, as the skylight drops in and installs right into the roof. A curb-mount is site-built to accommodate window and roof thickness. The skylight is then mounted to the curbing.

The type of ceiling dictates whether or not you need a shaft to direct light into the room. Cathedral ceiling skylights mount right in the roof. One hole does it all. A regular ceiling needs either a straight or flared shaft. A flared shaft directs more light into the room. With either shaft you'll have to cut and frame two holes - one in the ceiling and one in the roof. Reflective shafts increase the light provided. Remember that shafts need insulating to prevent heat loss.

What if you plan to install a skylight yourself? Well, unless you are comfortable cutting holes in your roof, the old adage "measure twice, cut once" definitely applies. You may want to measure three times when putting in a skylight, and always check for wiring before cutting anything. It's always wise to check the weather forecast and, lastly, get someone to help you.