you should be switching between demolish and snap punch.
Put up demolish first for the dot. then use snap punch the next time since demloish is already running, and then by the time you get your next couerl form demolish will need to be refreshed as its about to fall off.
You snap punch when demolish is already up, or if you know the thing you're attacking is going to die or something soon and know that demolish wont have enough ramp time.