Lay the starter row of metal shingles at the drip edge and affix to the roof with metal roofing nails.
Installing metal roof pipe boot.
Install remaining screws one inch on center around the perimeter of the pipe flashing.
The slide the boot down the pipe and leave it about 3 above the roof.
A different type of flashing is a chimney pipe boot.
Start with the high seam and install one x inch metal to metal screw.
Instead of having to cut flashing materials yourself you can buy a fitting boot for your chimney pipe.
Push your pipe flashing firmly into place.
Install a second screw on the high seam at the opposite end of your first screw.
Work up from the initial row starting at the lower corner in a diagonal pattern staggering the shingles to prevent gaps.
Metal roofing is also available in the form of shingles.
And begging to caulk around where the boot will go on the roof.
Place the new boot in the hole of the pipe and cut the boot on the line that touches the rim.