Skylight / November 10, 2018 / Delphine Demers.
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.
Another modern option is to have a replacement skylight with double panes of glass with a layer of argon gas infused in between the panes. New features and options make getting a replacement skylight a more viable option than just shingling over the old one. Remote controls make it possible to open and close a skylight on a whim rather than having to clamber about on ladders. Some skylights can also come with rain sensors so they will close the moment they feel raindrops or too much moisture. These options allow the skylight to vent the house while also protecting it against damage.
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.
You will need to position and mark the opening on the ceiling after the skylight is installed. Take into consideration the size of the room and the amount of light you wish to bring in and select the size and position of the hole accordingly. Once the skylight is installed and the ceiling hole is cut its then a matter of connecting the two with the shaft which is typically constructed from 2x4 or 2x6 lumber. The angles involved typically require some tricky framing and is probably best left to an experienced carpenter. After the framing is completed the inside of the shaft is covered with wood or drywall and the attic side is insulated to minimize heat loss.