This is a picture of what they call a curb mount skylight. I have outlined the basic operation of how they work.
- Basic operation of a skylight
Basic Skylight Operation
If you develop a leak in your skylight don’t panic most of the time it’s not as bad as it may seem. There are only a few things that can go wrong. Here is a quick tutorial on how to fix these problems.
Never caulk the lens! This is a bad idea and in time will leak again. Also you will be able to see the caulking from inside, this looks very bad. And you will end up having to replacing the sky light.
Common causes for skylight leaks
1. Plugged up weep. The weep is the area where the water runs out of the skylight and on to the roof . These become clogged due to blowing dust, roof debris and the accumulation of dirt washing down into the lens and plugging up the water trough inside of the skylight.
Solution: remove the screws that hold the top metal frame down onto the lens. Remove the lens (careful not to rip the rubber seals) Check to see if the water trough has any dirt or other debris impeading the flow of the water out of the skylight. If so clean it out and then carefully reassemble the skylight. Run water over the skylight lens and check for leaks.
2. Broken, Cracked rubber seals. (see above for lens removal) Check to make sure all the seals are in place not broken or cracked. If seals are worn broken or cracked go to your local hardware store and ask if they carry new ones. The rubber seals are what prevents water from running back past the water trough and into the house.
3. Cracked or broken lens. Skylights typically have two lenses and is unlikley. You can spot cracks or failed lens typically there will be moisture trapped between the two lenses and you can visually see this. If this is the case remove the lens and check your local hardware store for a replacement. Availability depends on skylight size and the age of the skylight.
Typically when you have a leaking skylight you will notice that it is leaking at one of the four cornners of the skylight. If you have checked everything above and all looks good then it may not be the skylight at all, and may be the roofing around the skylight. If this seems to be the case check around the skylight for obvious things holes,cracks,roof splits and such. If you can’t find any thing wrong cover the skylight with plastic weigh the plastic down on the roof with bricks or something heavy on all sides to avoid more drywall damage and call your roofing contractor.
Replacing your curb mount skylight.
If you want to save yourself a few hundred bucks you can replace the skylight yourself.
To remove the skylight remove the screws or nails from the bottom of the skylight on all four sides (the amount of nails depends on the size of the skylight). Once all nails/screws have been removed. Grab the skylight by the sides and pull straight up on it. If the skylight is stuck work it free from all sides. Careful not to damage the drywall inside. Once the skylight has been removed take it to your local hardware store and get a replacement (depending on the size).
Once you have your new skylight set it down over the curb apply pressure to the top and re-nail/screw it. Use one nail on opposite sides to hold it in place then re-nail the rest and you are finished.
The roofing is wrapped around the curb and the skylight fits around the curb so the roofing should not be affected.
This removal precedure is for curb mount skylights only pictured above. Self-flashing skylight (pictured below ) removal is a whole different proccess and should only be done by a qualifed roofer . However the leak detection and lens removal are the same.
self flashing skylight