Skylights: Let The Light In
Yes it’s true. In real life we are actually honest to goodness remodeling contractors. As remodelers are able to stay up to date with what folks want and desire in their homes – allowing us to keep our hand on the heartbeat of the industry. We are kept abreast of what folks want – or not – and what their fears are surrounding certain aspects of home improvement. Take skylights for example: Most people would like to have as much light in their home as possible. And those same people all say that they would love to have a skylight or several. Unfortunately, these same people are all afraid to commit to an installation because they perceive a skylight as a rain forest in a frame – a veritable plethora 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 air tight. As we are learning air tight means 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. Not a good thing, but with windows you can count your blessings. With skylights the condensation also drips downward – toward the floor – where you may be standing – or where you may have an expensive piece of furniture from which to begin a science experiment. If your windows condense there is a very good chance that a skylight will too. Air movement is air movement and when it doesn’t move properly at window level it will probably not circulate well at skylight level either.
Having said all that, we would like to say that we absolutely love skylights and the piece of the outdoors that they bring into our homes. Truth is a skylight doesn’t have to be a rain generating device at all. If properly installed a skylight can be a real plus in a room with only a remote chance of condensing or leaking. Here is the list of pitfalls you will need to be careful of when deciding to add 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 most certainly be exacerbated by the addition of a skylight. Wait until you replace your roof. In fact, skylights are best installed when the roof is being replaced. Yes, we realize that ours is not a perfect world, But, at least there is some compensation for those whose roofs are too far gone to add a skylight right away. By the way, roofing is cheapest in the spring. Roofers seem to run out of work right after the snow melt. Slow times mean low prices.
- If your skylight has to be tunneled from roof to ceiling you must make absolutely sure that the sidewalls of the chase 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. Plastic or glass, an insulated skylight is superior to one with only one layer of protection. Who was it that said two heads are better than one?
- It isn’t a must, but you may want to consider using an insulated glass lens rather than a plastic one. If you want to know the truth, we prefer glass over plastic because the glass type insulates better. Years ago we installed a 3×6 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. Even better are the operable skylights that are electrically and remotely controlled. There are even some electric models that come with a rain sensor that automatically closes the skylight when it begins to drizzle outside. What next?!?
- Keep in mind that a skylight well is a container (an upside-down container) that is perfect for catching and holding the kind of air that causes condensation – OK, rain. To reduce the chance for such condensation you must somehow cause the air in the skylight well to move. Remember the movie the Karate Kid? “Breathe in, Breathe out!” Even if the air at floor level is moving well it may not be doing the same thing at the ceiling. Installing a decorative ceiling paddle fan near the skylight well can make all the difference in the world. And there are so many choices available. If a paddle fan isn’t to your taste you can do a tiny low voltage exhaust fan in one of the walls in the well itself. Move that air.