How to Make Your Skylight Leak Proof

A very annoying, and sometimes costly, thing to have is a skylight that leaks. You should use waterproof underlayment as well as weave metal step flashing on the shingles on your roof in order to make your skylight leak proof. This is not a difficult job and can be an important one so water does not leak into your home.

Many skylights will sit on a raised curb on your roof. This curb is made with waterproof metal flashing. You should be able to reuse the metal flashing if you are careful when removing it. If it is damaged when you remove it you will have to purchase new metal flashing. Many times you can buy the waterproof metal flashing from the skylight manufacture or a roofing company.

The first thing you have to do is to remove the counter flashing of the skylight. On some skylights you will have to remove the entire glass frame. With some types of skylights you only have to unscrew the metal channel from the curb. Now carefully pry up the shingles pulling up the nails so that you can save the flashing.

Now you can reassemble it to make your skylight leak proof. The pieces of metal flashing do not need to be sealed to one another so you will not need any roofing cement. This is because water will run downhill so they only need to be installed in the correct order on your roof.

Here are a few steps when reassembling the skylight in order to make it leak proof:

∗ The first thing you need to do is install self-sticking waterproof underlayment. The underlayment should be 6 inch wide strips that are self-sticking. The underlayment will direct water that can get through the metal flashing directly onto the roof. When you install the underlayment do it from the bottom up. Be sure to lap each piece on top of the lower piece.

∗ Set the bottom piece of flashing on the top of the shingle course. Nail it down but only at the upper corner. Make sue you do not nail it directly to your roof.

∗ Now weave the step flashing up to the side of the skylight when you are installing each shingle course. Again, nail it to the upper corner.

∗ The upper flashing piece is a single piece that will wrap around the sides. The fabricated pieces will has seams that are both soldered and sealed and will have corners.

∗ Fix and then install the next row of shingles. Around a half an inch of the flashing should be left exposed.

∗ The last step is to lay the skylight back on.

∗ When you are finished take a bucket of water and pour it around the edges of the skylight. If water is still leaking in try to find the leak and fix the underlying and the flashing again.

Author: Jason Green