Skylight / July 9, 2018 / Delphine Demers
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.
Skylights may seem inexpensive at first glance since a quality 2x4 foot skylight along with a flashing kit costs anywhere from $100 to $400. However you need to consider adding another $3000 for installation costs. That being said you first need to carefully evaluate if installing a skylight is the right thing for your home. Till recently having a roof slope determined if you could install a skylight. Flat roofs or those which were too steep required special tools and techniques. However many of the skylight kits available today include a comprehensive installation kit and procedures which permits it to be installed on all types of roofs.
For one thing skylights are positioned in such a way that they are inaccessible unless they are operated by remote. Even in cases of motorized skylights which are easily manipulated there are still some disadvantages that are inherent to skylights that are not present or minimized in windows. Vertical windows lose less heat by convection when compared to skylights. Also since windows are generally protected by overhangs or shrubs they lose less heat by radiation. On the other hand skylights are directly exposed to the sky. Thus they lose more heat by radiation. Proper insulation can reduce this heat loss to a large extent. In the summer season skylights are more exposed to the direct heat of the sun than windows.