Installing A Skylight Without Leaks

When our family quickly began outgrowing our home, my husband and I couldn't decide whether to add onto our current home or move into a larger one. One day, when we were checking the local area looking for "home for sale" signs, we saw a sign we couldn't take our eyes off -- there was a large plot of land for sale for a great price in a great location. We had never thought of building our own home before, but after a little research, we realized that it wasn't as costly as we thought, especially considering the great deal we got on the land. The entire process was a learning experience, but thankfully, the building team was very pleasant and helpful. We now love our new home, and I am excited to share our experience on our new blog. I also plan to post many planning and construction tips!

Installing A Skylight Without Leaks

19 November 2014
 Categories: Construction & Contractors, Articles


Skylights are a wonderful way to get natural light into your home without worrying about your privacy. However, as with any hole in the surface of your roof, skylights have the potential to be the cause of leaks. The enjoyment of your skylight is going to be seriously hampered if you have to keep buckets under it to catch all the leaks. The secret to avoiding this is to install it right the first time.

Use the Joists as Your Guide

You are actually going to need to cut two holes in your attic (unless it is finished). One going out to the roof, and one going down into the rest of the house. In both cases, you need to cut into as few joists as possible for the installation. These beams are a major part of what holds up your roof, and if you cut into too many of them your roof could start to sag. Even if your roof is exceptionally light, the skylight could sag over time, leaving space for leaks.

The key to making sure your skylight is properly supported is balancing the weight. That means framing the new skylight exactly halfway between the remaining supports. The directions that came with the skylight should tell you how thick the frame needs to be. Essentially, the bigger the skylight, the thicker the frame needs to be.

Insulate as You Work

Water is not the only type of leakage you should be worried about. Air leakage can cost you big time if it is allowed to continue. As you frame in each section it is imperative that you take air leakage into consideration. Use sheets of insulation to cover the new walls as they are built, and a liberal application of caulk will seal any cracks.

Every few years you will need to recheck the seals in order to ensure that no new leaks form. Since the sealant process is so similar to your window maintenance, you may even want to do them together. If you allow these leaks to grow they will eventually allow in water as well as air.

Install the Skylight Carefully

It is imperative that you follow the manufacturer's directions during the installation. There are several types of skylights, and each has slightly different installation steps. This is further complicated by the fact that your installation style will depend on your roof type and the size of the skylight you are installing.

Once the skylight is in place, you need to repair the hole in the roof. The skylight installation kit should include flashing to encircle the skylight. Use plenty of overlap in the flashing to ensure water cannot work its way in over time. Remember that you want this skylight to remain water right for years, and sloppy installation is the best way to ensure that this will not happen.

Finally, add shingles back around the flashing. If you were careful when you removed them, you might even be able to use the same shingles. If too many are damaged, you will have to replace them with spares.

Installing a skylight is no small task, and after reading these directions, you might feel like it is simply too much for you. If this is the case, have no fear! There is nothing wrong with deciding that a project is just not for you. Hiring a local roofer to handle the installation might cost you a bit extra up front, but you can be sure that you won't have issues in the future. Water damage from a leaking skylight is a far more expensive proposition than a few hours of labor from a qualified professional roofer from a company like Roof Tech