A hand hacksaw would take months. Don't try to bend the points back and forth with a hammer in an effort to break them. The shanks of roofing nails are too thick for this and, if you try, you are likely to make the nail hole in the sheathing much bigger. You could also damage the shingles this way. Q. My pressure-treated porch floor has tight floorboards where the water beads up.
Trouble is, the water freezes, making it hazardous.
The floor is exposed and water will freeze on it no matter what you do, just as it freezes on a sidewalk or any other smooth surface that tends to hold water. Obviously, this would require taking up the floor. Salt might damage the painted or stained floor. Sand will help temporarily but will make a mess that will be tracked into the house. Putting down non-slip appliques would require too many, and the water still will freeze on them.