I have a 130 year old house with original floorboards made of 1+1/4 inch thick pitch pine (much, much tougher than today's cheap pine - it's like steel).
There's a section of floorboard that's been cut out to make an inspection hatch it to run cables, and it has been done badly - the cut (with a circular saw, I presume) almost missed the joist underneath, so the 'hatch' looks pretty precarious.
The cut is across 3 boards, and in an effort not to cut beyond the 3, they've stopped short, and just pulled up the boards, breaking the last one so that it's left a spur of wood sticking out (which you can't see when the hatch is in place).
Anyway, I'd like to extend the hole by another inch, and replace the 'hatch' boards with some slightly-longer boards take from somewhere else. I don't want to lift the boards that I'm cutting, because they've never been taken up, and I know from experience that lifting floorboards is bad for them. So, I want to cut them in-situ.
What I can't figure out is how to cut an inch off those boards, given that they're on top of the joist, and hemmed in by boards that I don't want to touch. I could probably use a circular saw for the middle part, but how to get the edges? I've had mixed results in the past with a floorboard saw, but it's really really difficult with boards as hard as these. Likewise chipping away with a chisel doesn't seem viable.