Normally, my vinyl-flooring installation jobs involve one or two rooms, and there are typically two or three door openings. I prefer that the vinyl tuck under the door jambs and casings — it looks better than scribing the vinyl to the casings, and it’s a lot less tedious. To trim the bottoms of the casings, I use an offset backsaw resting on a wood shim to trim them in place, or I pull the casings, trim them and then nail them back up. There were no less than a dozen large, complicated old door jambs in a house that I recently worked on. Not only that, there were variations in floor heights, and the customer had requested a thicker-than-normal grade of vinyl flooring for the job. The problem became how to shorten the casings efficiently to make room for the vinyl without pulling the trim.
As shown in the drawing, my solution was to double up a couple of wood-cutting blades in my reciprocal saw. I used two long blades that were flexible enough to follow the floor contours. Their increased kerf width cut the right amount off the bottoms of the casings. It was clean, the customer happy.
Jere Anderson, Spokane, WA