removing chimney/sealing roof

I have an unused chimney (from an old oil burner)that comes up through the roof at the point where the two sides of the roof meet (i.e. the highest point)it is about 7' in from the side of the house.

I've determined that this chimney is not load-bearing and want to remove it, but I'm not sure of the best way to patch the roof. The opening will be about 1' by 1' square.

 

I forgot to mention that this is a brick chimney with a asphalt shingled roof, and I am removing it completely - down to the cement slab.

 

I'm not a pro at this, but I would remove the chimney to below the roof line (into attic), remove the old flashing, and clean off a section of the roofing that extends beyond the two adjoining rafters (16" or 24" centers?).
Cut-out the chimney hole sheathing half way onto the adjoining rafters, and replace that section of roof sheathing with the same thickness of plywood (5/8? or 3/4?)nailed to the rafters and to cross pieces between the rafters in the attic, cover it with roofing felt slipped up under the felt above, and shingle over it to match the rest of the roofing.
Shouldn't be too difficult to do.
One of the pros here will probably have better ideas.
Good Luck!
Mike

 

Just make sure that if you have more than one layer of shingles that you also build up to match.

 

You guy's advice worked like a charm. The chimney came out in a snap, and the patching was a breeze. And wouldn't you know it - right after we got done, there was a soaking rain (that's summer in Seattle for you) but the roof was tight as a drum.