Have just asked my hubby as he had to do this with ours you need to screw a batten on to the shed to fix brackets on for the guttering and no to the second part of the question hope this helps.
Guttering shed overhang.
Is it possible to buy brackets that extend to account for the overhang.
However if you choose to install gutters made of aluminum or similar metals the process is very similar.
The last would be a roof hanger that is nailed to the roof surface under the shingle tab.
The attachment is one of several methods.
This type of guttering for sheds is pvc so it is quite durable.
Now you can collect the rainwater e g.
One is via a spike through the gutter and into the fascia.
Guttering for one roof edge only for e g.
Your shed porch or overhang.
For structures like garden sheds easy to cut and snap in place pvc guttering is an ideal choice.
Another is a hidden hanger that hooks inside the gutter and is also nailed through the face.
Attaching a gutter and downspout system to your shed can prevent muddy ground around its base and prevent its walls from rotting prematurely.
If you live in a warm place with sporadic rain you can hang gutter hangers close to the middle of the gutter with a spacing of no more than 36 inches or three feet apart from the center.
In a water butt or drain it to the garden.
The rainsaver is a proprietary brand that is just one of many similar types of clamp on guttering designed specifically for sheds.