This is a long video but it will show you how to do it.
How to install rolled roofing video on a flat roof.
Visit your local hardware store and ask for enough rolled roofing to fit the area of your roof.
Prepare the roof by tearing off the old shingles or by preparing for a reroof.
This should give you a 1 inch overhang on the eaves including the top edge.
For a flat or nearly flat roof use double coverage although a torch down modified bitumen or epdm roof is a better solution.
How to remove repair and install a flat roof.
Working with a helper expect to spend half a day installing flashings and roll roofing for a 700 square foot roof with modest complications.
Make sure you offset yo.
And tie it into your hip roof.
Place the top edge of the roofing along the chalk line.
To apply rolled roofing you ll need your roof measurements a broom chalk to mark lines a razor blade to cut the material roofing cement nails and a hammer to hold down the material.