Everybody knows what an axe is. Many people know what an adze is. Who knows what a froe is?
A froe is an ‘L’ shaped tool for splitting wood precisely, and the process of splitting wood this way is called riving. This tool is incredibly handy for splitting wood into kindling safely and quickly or even into boards. Boards and shakes created by riving are often stronger and more dimensionally stable than sawn boards. This is because almost all the wood fibers can run all the way from one end of the board to the other. It also is less wasteful, meaning you can get more roof shakes out of a single cedar log.
To use a froe on short stock, place the tool on the end of the log as shown. Then with a wooden mallet or cudgel, strike the back of the froe to drive it into the log. Once it is well seated in the log, use the handle like a lever and pry the log apart. Never use an axe or metal hammer on a froe, doing so may damage your tools and the shrapnel could hurt someone.
Straight grained GREEN wood is the best to use a froe on. Knots can make riving quite difficult, but proper placement of the froe and splitting where the wood is straight can help. I have had good results with green ash and some oak. Birch is also excellent, however you will want to cut the bark off or in vertical lines as it will hold the log together when you try to split it. Cedar is the traditional wood for roof shakes/shingles, and riving is also an efficient way to split basswood into smaller blocks for figure carving. It is good to experiment with the different woods you have available.