cutting standpipes that are against a wall or in a corner | Terry Love Plumbing Advice & Remodel DIY & Professional Forum

I have a number of 4" pvc stand pipes that need to be trimmed down, prior to new gutters being installed.

I always struggle when the pipe is against a wall or in a corner with cutting them off cleanly and flat... esp. when I take a multi-tool to it.

Is there a trick do doing this? I am thinking for the ones against a wall, using a back saw or similar saw with a wide blade may help. Any tips or tricks on this would be great.