Secure the horizontal flange to the roof.
How to fit asphalt roof shingles.
Start by laying asphalt felt or other underlayment over the roof.
Apply a heavy bead of asphalt cement.
Overlap each row at least 3 to 4 inches.
Place the second step flashing piece over the end shingle in the first course by positioning it 143 mm 5 5 8 above the bottom edge of the exposed asphalt shingle.
Dot the cement under and around the edge of the last ridge shingle where you removed the nail line.
Nail at the four corners to the end of the ridge and always add a little dab of tar to cover the nail heads.
Using your staple gun secure the felt to the roof.
If you live in an area with inclement weather you should consider using a special ice and water protector.
How to install asphalt roof shingles step 1.
Install new flashing metal.
Also apply asphalt cement over the nail heads exposed on the last ridge shingle to prevent water leaks.