Grab attack

[Kwauss]

When you have an attack such as an monster's grab attack that causes a combat maneuver to trigger when you hit, do you roll and add your CMB separately, or just add the CMB to the initial roll instead of attack bonus?

[TyrKnight]

I have them roll separately and add their CMB. The rules usually mention if the roll carries forward to the next check. This one doesn't so I presume it is a separate roll.

[Are]

The CMB check is a separate roll.