To cut a log into sections without pinching the saw blade, use a timber jack.
1. Slip the jaw around the log a few feet from the cut end, with the T-shaped kickstand between you and the log. Push the handle away until the inside of the jaw touches the bark.
2. Ease the handle back until the jaw bites and the kickstand jacks up the log.
3. Lay the handle on the ground and saw the log into lengths that will fit in your fireplace.