In the Wall-phaser page, It says that if it touches Stone bricks, Logs or Wood Planks, it will turn them into cracked versions of what ever that is. The Cracked Stone Bricks are already in the game, and their fine, but Cracked wood and logs have a lot different to bricks.
1. If wood of either form is submerged in water, or is contacting water, It has a Very tiny (100 000 per tick chance) to become cracked, (not on multi-level boats, once they have been made) and if in the rain a 1 in 1000 chance per tick during the rain to become cracked.
2.If nothing is supporting cracked wood or logs, if you walk on it, it may break (1 in 5 chance)