How to flash new curb on old roof

This is a modified bitumen flat roof. Normally the cap sheet would be run up the curb and then a flashing (made out of cap sheet) would be applied over that. I would extend it 6 inches on the roof and all the way up and over the 2x4 flashing.

When installing a new curb on an old roof, do I just flash with a cap sheet and not worry about the roof cap sheet running up the curb? Should I make the cap sheet flashing extend further on the roof?

The flashing sheet is separate from the field sheets, should be flashed as normal

Thanks. The manufacturer states that the field sheet should extend over the vertical surface a minimum of 3 inches. How do you do this if you are cutting into the field sheets to install a new curb?

For a torch applied modified bitumen roof the flashing is fabricated from the field sheet.

Install your new curb and flash it with the field membrane, go up & over the curb & 6" onto the existing roof.

Is the existing roof smooth or granulated.

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