Make sure you offset yo.
How to remove roll roofing.
Place the top edge of the roofing along the chalk line.
If you can lift the edges use some more cement to seal them in place.
How to remove old flat roofing.
Take special note of the corners and edges of the roof.
Leaks form and the materials erode into something that is better.
Clean the rolled roofing before you finish.
When you re finished trimming test the edges to see if you can lift them.
This should give you a 1 inch overhang on the eaves including the top edge.
Flat roofing has some advantages but when it ages or falls into disrepair it can be troublesome.
This is a long video but it will show you how to do it.
Use your razor knife to remove any excess rolled roofing.
This will either be laid out shingles or rolled roofing folded over the peak of the roof.
How to remove repair and install a flat roof.
Pry up the ends and pull off the cap.