Nail the new shingles down with roofing nails so the nails are covered by the shingle above.
What does a roof jack look like.
You can usually feel sheathing nails which are driven into rafters through the underlayment attach a jack by driving two 16d nails never roofing nails into a rafter.
A roof jack will not do you any good without planks of lumber to span them.
Look for dents and dings on gutters and downspouts.
It might be something.
Roof jacks provide a stable surface to work increasing safety and making it easier to apply roofing.
Dented gutters downspouts.
What causes a sagging roof line.
If you can see a dip curve or swag on the peak when standing in the street your roof has a problem.
Cut roof shingles to fit around the roof jack and insert them under the existing shingles.
If it does follow our first installation procedure.
What exactly does hail damage on a roof look like.
If it doesn t have a corner and simply looks like the image below follow the second installation procedure.
Use a hammer to bend the top edge of the soft lead roof jack down into the vent pipe.
Roof lines should be arrow straight.
Avoid using short pieces as the risk of a length of lumber tipping upward if you should happen to step onto the end of it is greatly increased.
Quick things that point to roof hail damage.
Also before you start installing your flashing you need to look to see if the wall in question has a corner on the roof face as in the image below.
Ideally locate a rafter below the sheathing.