Arizona Roofer

Your Roofing Questions Answered

Skylight Repair

June 23rd, 2012

The two most common sources of roof leaks on a foam roof (or really any type of roof) is skylights and scuppers. Generally when a roof leaks it’s because of a failed penetration on the roof. Leaks are usually not found in the membrane it’s self. Curb mount skylights are the easiest type of skylight to change and usually come in 2 common sizes 2′ by 2′ or 2′ by 4′ and are avalible from home depot or lowes. It should be noted that they will carry single and double dome skylights, the difference being a single dome has one lens where a double dome has two lenses. If the space under the skylight is liveable space it requires a double dome, if it is not liveable then you only need a single dome. I recommend double dome sklights no matter where they are going it’s twice the protection for about $10 more.

In the picture below it shows a picture of a skylight that has been sealed shut and no longer functions correctly. This pretty common thing being done and it only woks in the very short term and should not be done. The time it takes to seal it up and the price you might pay someone to do this you could have replaced it for less.

failed skylight
sealed skylight lens with failed coating.

In this next picture it shows how a skylight functions.


This is how a skylight functions

functioning parts of the skylight

In This last picture it explains how to remove the skylight

how to change the skylight

Be sure to remove all 8 nails or screws before removing

Removing and replacing skylights isn’t as hard as you might think. Find the nails or screws holding the skylight on remove them and the gently pull the skylight off. Once you have it off put the new one in place and push it down so that it’s flush against the top of the curb then nail it in place. You can probably remove and replace on of theses in about 15-20 min.


Failed Skylight

July 15th, 2009

I gave a tutorial on finding and fixing leaks on skylights. It also covered what to and what not to do to fix them . And it didn’t take long to find a failed skylight that I could take pictures of to further explain how Skylights work and once again explain what not to do.


In this first picture it shows a caulked skylight lens. This is not recommended. Over time the caulking fails and the skylight will leak again


caulked lens

Caulked Skylight Lens


In this picture it shows the reason why the sky light was leaking in the first place. If you look the “weep” (this is where the water comes out of the skylight). Has been caulked and foamed shut, blocking the waters exit. The water traped inside can only fill the trough and leak inside of the house.


inside workings of a skylight

This is the inside of the skylight


The operating function is as follows. Water runs in between the lens and the metal frame (see picture 1). Fills up in the trough. The water travels to the cornners and then out through the weep on the side. This skylight is ruined and needs to be replaced. At a price around $150-$200 or more depending on who does it!

Understanding Skylights

July 3rd, 2009

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.


Curb Mount Skylight


Skylight removal

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).

Skylight Re-installation

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