Skylight / July 11, 2018 / Nicolas Charlebois
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.
When these are pulled away and removed the drenched and water damaged roof beams come into view. Moisture comes from both inside and outside. Weather isnt the only thing that causes skylights to leak. Warm air from inside the house can catch in the skylight as it rises on warm air and then drips down onto furniture and valuables below. Modern skylight replacements can come with what is called low-e glass. This low emissivity glass keeps energy meant to heat or cool a room in and helps to reflect heat and cold out and away from the light itself. This is usually done through a special film that the glass is coated with. This film can block out UV rays and comes in many different filtering shades.
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.