Roof jacks provide a stable surface to work, increasing safety.
Roof jacks provide a stable surface to work, increasing safety and making it easier to apply roofing. Ideally, locate a rafter below the sheathing. (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.
To remove a jack when you're done with it, tap up with a hammer to disengage the jack from the nails. To drive the nails in so they don't poke through the roofing, slip a flat pry bar under the shingle and over the nailhead and pound the nail down. Or, if the tab is flexible enough, lift it as you nail.