For gabled roofs the roof rafters extending beyond the wall caps creating an angled roof overhang on the eaves.
How far over the wall should the roof extend.
2 i call them the baker principles.
Over roof insulation the gable overhang has been cut flush with the wall sheathing.
Too much overhang and the shingles could blow off in high winds.
With a flat shed roof the roof simply extends past the wall plate to provide an overhang.
Coming from me it should by now.
How far should the roof extend over the gutter.
Connect the water control element layer of the roof to the wall the air control element layer of the roof to the wall the vapor control element layer of the roof to the wall and finally the thermal control element layer of the roof to the wall.
How to extend rafters.
I have a lovely old bloke next door in his late 70 s who has 12 x 7 m carport that was installed pre google earth.
This will protect a roof from most types of damage.
Because this style of a shed has a flat roof it can facilitate a wider overhang which is ideal for storage.
Two feet is the general maximum length for a typical roof overhang.
The outer ends of a roof s rafters the sloped members that give the roof its pitch provide shade divert rain and create soffit space for attic ventilation.
The back edge of the gutter should tuck up behind the dripedge if you have it otherwise the edge of the shingles should extend well over the back half of the gutter so the drips cannot get behind it and rot the fascia board.
The edge of the shingles should hang over a roof between an inch and an inch and a half or between a half inch and three quarters of an inch if drip edge flashing is installed.
Also note that a new fully adhered membrane is installed on the original roof deck replacing the one installed 17 years ago is folded down to catch the top edge of the wall water control layer.
A normal gutter will have about 1 2 3 4 of its width sticking out beyond the shingles to catch the runoff.
Here phil explains how much overhang a roof should have at the gutter.
Some metal roofs have wood framed eaves that extend several inches or a foot beyond the house or shed wall to support metal roofing.
Too little can allow water to seep into rake or fascia boards.