Installing a Skylight
Installing a skylight isn’t an easy task. There are many things to consider before picking up a hammer and calling the building department in your area.
Not only is there technical knowledge required, but in some jurisdictions, you may need to obtain a permit in order for your roof to support the additional weight. Here’s what you should look for when considering installation:
Many skylights need to be placed directly in the center of your roof. Too far off and you’ll never get enough light, too close and it will hit the roof at an angle that results in poor illumination. So how do you find this perfect placement? The best way is with a surveyor’s transit or dumpy level. You can rent equipment from your local hardware store, usually for around $20/day. Once you’ve set the pivot point at the highest point on your roof, align it to face due south and begin taking readings along two separate points of your roof.
The first reading should be near where you plan to install the skylight while the second should be a few feet away. If you’re lucky, you’ll get an even spread of measurements closest to 90 degrees South on your transit. Mark these locations and then simply triangulate between them to determine where your skylight will fit perfectly onto your roof.
This works for more than just skylights — any roof-mounted equipment that you need to mount at a specific angle will follow this same procedure.
Many skylights have moving panels for ventilation. These are often used even in very cold climates, where the heat loss is offset by the benefit of fresh air entering your home. However, these vents can lead to issues if not properly sealed.
When you are installing the skylight, use caulk to seal around the perimeter where the roof meets the frame of your new skylight. If air is allowed in here, moisture may find its way onto your ceiling below and over time lead to expensive damage.
Every few years, inspect this area for signs of leakage and reseal as needed.
Perhaps the most important thing to consider before installing a skylight is whether or not your installation meets building code requirements in your area. While all codes are different, the standard generally requires that skylights must be designed for specific loads depending on their type and location on the roof. Just because you’ve met this requirement doesn’t mean that your skylight is safe, either — there are all sorts of other things to take into account.
For example, many jurisdictions require that a certain distance must be maintained between the bottom of the skylight and the roof. This ensures an emergency exit even during heavy snowfall or other weather events. For high-rise buildings, this distance must be even more to account for wind gusts that may catch a person unaware and blow them off the roof.
In most cases, having a structural engineer sign off on these requirements is enough to permit your installation. If you’re installing skylights as part of a building permit, it’s likely that one of their engineers will be the one to sign off on these requirements.
Many people are installing skylights in order to save on their energy bills, which is often possible but not always the best solution. The reason for this is that while skylights can provide excellent natural lighting, they also create a series of thermal issues. For example, while heat loss is reduced, heat gain from the sun’s rays can raise the temperature of your roof to dangerous levels. This not only increases your energy bill but can lead to shingles curling and other thermal problems that result in damage and leaks.
As such, if you’re considering installation skylights, consider instead installing a series of solar tubes to provide the same illumination without the expensive and dangerous ramifications.
When installing a skylight, one popular option is to add fans so that you can use it for venting purposes. It’s an excellent way to supplement your air conditioning during warm months and even help remove hot air from your home in the winter, but if not done properly it can lead to problems.
For example, if you don’t take into account that your skylight is drawing in fresh air from the outside, this may create a negative pressure inside your home and cause backdrafting of your furnace or even combustion gases to leak into your house. If this happens, not only will you risk carbon monoxide poisoning but your energy bills will skyrocket as you use more energy to compensate for the air being sucked inside.
As such, ensure that you have a balanced ventilation system if you’re looking to install both an intake skylight and an exhaust fan. If you are using one or the other, take care not to have them draw too much air into or out of your home to compensate for the other.
You may also consider pairing fans with a passive solar chimney, but be aware that these systems work best in tandem and therefore require proper planning. Otherwise, you may find yourself canceling out each other’s benefits and wasting energy as a result.
When installed properly, skylights are an invaluable addition to any home. However, if they’re not done right or not maintained over time, they can cause problems that end up costing even more than you’d spent on the skylight in the first place. As such, before installing a skylight take into account your climate and whether or not it’s actually practical for your needs.
For example, in colder climates skylights can turn into icy death traps that no one will be able to escape from when the temperature drops below freezing, while hot humid climates may get so stifling without proper ventilation that you’d be better off with a box fan instead. In addition, consider your energy usage and whether or not you want one so that you can plan for it properly and avoid damaging your home.
And, of course, ensure that there is at least a four-foot gap between the top of the skylight and the roof to prevent any accidents from occurring as well as ventilation issues from developing. Finally, take care when installing fans or passive heat systems to ensure that you’re not canceling out their benefits and wasting money as a result.
In short, skylights are wonderful additions to any home but they aren’t right for everyone or every situation. As such, before installing one it’s important to consider your climate, energy usage, safety issues, and whether or not the skylight is practical for your needs.
If you do decide to install one, take care and ensure that it’s done right so that you can enjoy its benefits without creating any more problems than you started with.