I need to install the stove pipe for our Kuma oil stove. 6" triple wall. My question is how folks install the roof flange collar. Metal roof over plywood. 5/1 2 pitch. Been a while since I've done one.

I will cut the hole 2" larger to keep combustibles away as required. Question here, should the metal roofing be cut to fit the pipe and the plywood cut 2" larger ?

My thoughts are, I would install the pipe and insure that it is plumb. Trace outline of the flange. Cut Metal roofing from the hole to a line draw 3" below the top flange line . Slide the flange under the roofing at the top. Align with marks on the bottom of the flange that were made prior when plumbing the pipe. Install sealant under the metal roof. Screw down with roofing and reseal the edges.

Any tips or suggestions appreciated. And what type of sealant are you using ? Thanks