As remodeling contractors, we are able to stay up to date with what folks want and desire in their homes. We are kept abreast of what folks want and what their fears are concerning aspects of home improvement.

Take skylights, for example.

Most people would like to have as much light as possible in their home. And they say that they'd love to have a skylight or several skylights. Yet, these folks are afraid to commit to an installation because they perceive a skylight as a rain forest in a frame--a source of condensation and a leak hazard.

Fact is, in some cases, such fear is for good reason--especially in today's modern homes where every nook and cranny is completely sealed and airtight. An airtight condition causes less air movement in the home. This means more condensation on windows (moving air absorbs moisture). Condensation that gathers on windows can gather on a skylight in the same way and for the same reason. The difference is that on a window the condensation runs down the surface of the glass to the window sill where it puddles and can become a science experiment.

With skylights, the condensation also drips downward, but toward the floor, where you could be standing, or where you might have an expensive piece of furniture. If your windows condense, there is a good chance that a skylight will too. When air doesn't move properly at window level, it probably won't circulate well at skylight level either.
Having said that, we still love skylights and the aspect of the outdoors that they bring into our homes. A skylight doesn't have to be a rain-generating device at all. If properly installed, a skylight can be a bonus to a room, with only a remote chance of condensing or leaking.

Here is the list of pitfalls you will need to be careful about when adding a roof window or skylight:

• If your roof is badly worn or close to shot, don't try adding a skylight. The already poor condition of the roof will be exacerbated by the addition of a skylight. Wait until you replace your roof. Skylights are best installed when the roof is being replaced. Roofing is cheapest in the spring. Roofers seem to run out of work right after the snow melts, and slow times mean lower prices.
• If your skylight has to be tunneled from roof to ceiling, be sure the sidewalls are well insulated. This is not the place to get ventilation to the skylight that will reduce or eliminate condensation. In fact, this is the worst place to let air into the home. During the summer, your attic can get hot enough to melt candles. Not insulating this area can result in heat loss in the winter (energy waste) and heat gain in the summer (more energy waste). Insulate and foam-seal gaps at all construction surrounding the skylight.
• Install the skylight on the north side of the roof, if possible. Although such an installation can add to the condensation problem, south-facing skylights can be incredibly hot.
• Never install a single-glazed skylight. Only use the insulated type. Whether plastic or glass, an insulated skylight is superior to one with only one layer of protection.
• It isn't necessary, but consider using an insulated glass lens rather than a plastic one. We prefer glass to plastic because it insulates better. Years ago we installed a 3x6 skylight over a pool table. That winter it condensed and the pool table got rained on. We replaced the plastic model with a glass unit and the condensation went away.
• Use a ventilated skylight and be sure not to plug the ventilation holes during installation. Even better, use a skylight that opens. Some models are available with a manual crank that can be operated with a long pole that collapses and can be stored in a closet. Operable skylights that are electrically and remotely controlled are even better. There are some electric models that come with a rain sensor that automatically closes the skylight when it begins to drizzle.
• A skylight well is a container that is ideal for catching and holding the kind of air that causes condensation. To reduce the chance for such condensation, you must somehow cause the air in the skylight well to move. Even if the air at floor level is moving well, it might not be doing the same thing at the ceiling. Installing a decorative ceiling paddle fan near the skylight well can make a big difference. And there are so many choices available. If a paddle fan isn't to your liking, you can put a tiny low-voltage exhaust fan in one of the walls in the well itself. Whatever it takes, move that air!