Skylights are a great source of light and visibility in most any area of your house. Not only are they great when the sun is shining, but they can be soothing when the rain is falling. Unfortunately, sometimes the relaxing rhythm of the rain falling on the skylight can be disrupted by leaks. If your skylight is leaking, you'll need to seal it. You can call a roofing contractor if you aren't comfortable tackling it yourself, but here's a look at what you need to know to do the job on your own.
Sealing a Skylight on a Metal Roof
Start by chipping the roof cement away from the edges of the skylight. Use a chisel or similar tool to do this, but be careful not to damage the roof around it. Once the cement is cleared away, cut some mesh roofing material into strips, and then place them around the skylight.
Embed them in roof coating to keep them in place and seal the outer edge of the skylight. Let the roof coating dry for a day, then apply one more coat.
Sealing a Skylight on a Shingled Roof
The first thing you'll need to do is figure out where the actual leak is. Cover the top half of the skylight with a thick plastic sheet and secure it so that rain can't get underneath. Spray water over the top of the skylight with a hose. Watch for any water inside. If you don't see any water inside, move the tarp to the bottom half of the window and repeat the process. This should narrow down the side that's leaking.
Pulling Up the Shingles
Once you know where the problem is, you'll have to remove all of the shingles around that side. Start about a foot from the skylight edge and pull the shingles up. Then, remove the roof tar around the skylight with a chisel. It'll take time for you to do this part, so be patient. Don't try to rush it, because you might damage the roof.
Applying a Water Barrier
Cut the roof felt around the window using a utility knife. Pull the felt out, exposing the roof deck beneath. Apply a water shield strip to the roof deck. Use adhesive water shield so you can just remove the strip from the back and apply it to the deck.
Restoring the Shingles
Once you have applied the water barrier, you will need to reattach the roofing shingles. This will mean applying a fresh layer of roofing tar and attaching each shingle properly. If you are not confident in your roofing skills, you can talk to a roofing contractor with experience applying shingles around skylights.
Other Possible Issues
If you find that this doesn't fix the water problem, you may be dealing with condensation instead of an actual leak. Sometimes, having skylights on cathedral ceilings or above multi-story homes can lead to some condensation because of the heat and humidity created when you cook, do laundry and wash dishes. Cut a small hole under the light well by the skylight to see if there's any insulation behind the drywall. If not, you can add some spray foam to insulate it. Opt for foam with minimal expansion, because it could damage the roof and skylight otherwise.
Another common cause of leaks is spider cracks in the skylight. Sometimes, fine cracks can lead to leak problems, and may even threaten the integrity of the skylight. If your custom skylight is cracked or damaged, you'll need to have it repaired or replaced.
With the tips presented here, you can combat the moisture and leaking problems that can plague skylights when the seal around the edge lets go. If you aren't comfortable with doing the repairs on your own, you will know what you can expect of the repair process when you call a professional.