Skylight / July 11, 2018 / Nicolas Charlebois
A skylight is like a window which has been placed in your roof. It has a frame specially designed to withstand rain and prevent leakage from rain and snow. To maximize a skylights use of natural light to illuminate a room or its passive solar heating potential you will want to take into consideration how a skylight is positioned. Facing north your skylight will provide fairly constant illumination but will not provide a lot of heat. Facing east it will provide the maximum amount of light and solar heat gain in the morning. Facing west your skylight provides afternoon sunlight as well as heat gain. A skylight facing south provides the greatest potential for winter passive solar heat gain than any other location but will often allow unwanted heat gain in the summer.
To maximize the energy efficiency of skylight windows you must choose the material carefully. Both glass and plastic skylights have their unique benefits and disadvantages. Glass is more durable but there are limitations in shape. It is also quite expensive. On the other hand plastic is flexible and can easily be bent or stretched to different shapes. It is inexpensive too. But plastic glazing has a tendency to change color after a while. More importantly irregular shapes lead to more heat loss as larger surface areas are exposed. Windows VS Skylights: It is wrong to believe that skylights can replace or take the place of windows.
The acrylic dome is typically mounted in an aluminum frame which is in turn mounted on a box called a "curb." Once the hole is cut in the roof to the manufacturers specifications the curb is typically constructed on-site to raise the skylight above the level of the roof sheathing. Site-built or factory-supplied flashings are used to seal the roofing around the curb. Domed skylights are available in clear smoked bronze or other tints. Some domed plastic skylights are flush mounted which means that the lens piece and flashing piece are both made of plastic and then placed on the roof without a curb. The problem with this type is that they are loud and very susceptible to leakage.