- Inspect the roof
If your roof has served you for 30+ years, chances are some shingles are broken. The horizontal edge where the shingles intersect will probably be irregular in some areas. Trim the irregular edges and flush them with small pieces of shingles.
- Remove ridge caps and nails
- Fix broken shingles
Should any shingles break while removing the ridge caps and nails, repair them using roofing cement. If an entire shingle is damaged beyond repair, replace it with a new shingle. The roof must be even before the layering of new shingles.
- Clean the roof
There should be no debris, leaves, broken pieces of shingles, or any stuff that might obstruct the new shingles and result in unevenness.
- Install valley flashing
Fix the valley flashing using nails on the outer edges. Use nail sizes that are long and strong enough to hold the flashing in place firmly.
- Install the drip edge
Set the drip edge over the gable ends. Next, drive steel nails through the drip edge to stick it on the roof.
- Install new shingles
Fit the first row of shingles as you nail them on the drip edge. The shingles should protrude over the drip edge by ¼’’. Install the remaining rows. The rows above should overlap the ones below by ¼’’. The intersection between the rows should result in a horizontal line.
- Fix the ridge cap shingle
Fit the ridge cap shingle over roof ridges. Use nails to fix the cap shingle on the roof. Just like the shingles, the caps should overlay each other by ¼’’.
- Inspect the roof once again to ensure there is no loose or broken shingle. Use the utility knife to cut any shingle edges that are not in plumb.