Domed skylights are a type of skylight that is distinguished by an oval shape that provides several advantages over the flat versions. Domed skylights are generally considered to be more esthetically pleasing, practical in terms of shedding water, and relatively easy to replace than flat skylights. As an added bonus, many manufacturers offer several versions of the domed skylight as very affordable prices.
Just like any type of skylight, the main function of the domed version is to allow natural sunlight to enter an enclosed space, such as a room, via a window that is set in the roof for the space. When most people think of a skylight, they think in terms of a solid section of flat glass that is set into an opening in the roof section, or a set of glass panes set into a metal or wood frame and inserted into the ceiling opening. The domed skylight offers an alternative to this traditional offering that is considered by many to be more decorative while still providing the same basic functionality.
Domed skylights are often made of clear acrylic materials. There are several good reasons for this. First, acrylic domes are lighter and thus place less of a weight on the supporting structure for the ceiling and roof. Second, the acrylic is more cost effective in many cases than using glass for large skylights. Finally, the acrylic tends to hold up just as well as glass in most weather conditions, but can be replaced with ease in the event of a problem.
A domed skylight in general offers some practical advantages that are not offered by a traditional flat skylight. The oval shape of the skylight provides a natural means of shedding water away from the skylight itself. This can be especially important when the general roof construction is flat and may have a tendency to allow water to stand. In addition, the domed skylight is usually very easy to install, and requires very little in the way of maintenance.
Critics of the design for a domed skylight point to several issues that can arise, especially if acrylic is used in the design. Cheaper types of acrylics have a tendency to yellow with age, which will interfere with the flow of natural sunlight into the space. Also, some forms of domed skylights do not retain heat well, which could mean higher heating and cooling costs.