Skylight / July 15, 2018 / Arnou Gabriaux
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.
There must be a clear opening in the area where the skylight is to be placed. A skylight that faces the East lets in plenty of morning sunshine while one that faces the West brings lets in the afternoon sunshine. It is important to know the amount of light and the type of light your skylight lets in. Afternoon sunlight can become uncomfortably hot if you live in a warm and dry place. The size of the room also has a bearing on the effectiveness of the skylight on your roof. If the room is small your choices are severely limited as skylights are best suited for large rooms. If you still want a skylight for a small room it is best to opt for an elegant pyramid skylight. This gives the illusion of space.
For example the optimum slope for a south-facing skylight in Columbus Ohio at 40º North latitude is 45º to 55º. Every skylight has a "shaft" which governs how much light is admitted into the room below. If all four sides are flared then the light is spread over a wide area. If your skylight has a shaft with perpendicular sides the light is focused straight below. If your skylights shaft is flared on only one or two sides then the light is sprayed in the flared direction. Ventilation If you wish you can have a skylight which also provides ventilation as well as light to your room. This allows you to release the hot air which collects at your ceiling.