Supporting a heavy floor beam or holding a long ledgerboard in place is common when building a deck, adding on, or doing major repairs. Unfortunately, so is the strain associated with these tasks. You'll never find a stronger, more tireless assistant than an automobile scissor jack. The long crank handle and threaded mechanism on the jack lets you raise or lower ponderous objects with surprising precision. And unlike some hydraulic bottle jacks, a scissor jack won't "leak" and suddenly drop while under pressure. Keep the jack from sinking into the ground by putting it on top of a 2x8 support board. If necessary, dig out the ground so the board is level.