Cutting down a tall tree can seem like a daunting project, but if approached in the proper way, almost any homeowner who feels comfortable operating a chainsaw can fell a tall tree. There are two main points to consider when you are cutting down a large tree. The first point is how tall is the tree and is there room for it to fall without damaging property or hitting power lines? The other consideration is how wide the tree is. In other words, will you be required to climb the tree in order to remove any wide branches before the tree is cut? If you can answer "yes" to those two questions then your job is well begun.
Estimate the height of the tree so you will know where the top of the tree will land when the tree falls. To estimate the height of a tree, cut a stick the same length as your arm. Hold the stick in front of you at arm's length and step back until the entire height of the tree is covered by the stick. Pace off the distance to the base of the tree and you will have the approximate height of the tree in feet. See the Resources section for additional information.
Survey the area and find a direction that the tree can fall where it will do the least damage to buildings, power lines and other trees.
Check the width of the tree's branches and determine if any of them need to be removed before the tree falls. If so, use a ladder and a climbing harness to get above the long branches and the use a chainsaw to cut the branches. In most cases only the long, lower branches will need to be removed as shorter, higher branches will cause fewer problems.
Notch the tree on the side where you want it to fall. Wear eye goggles, hearing protection and gloves, and make a straight cut to approximately the center of the tree at waist height on the side where you want the tree to fall.
Make a second cut, a downward cut at approximately a 45 degree angle such that your second cut will intersect your first cut approximately half way through the tree. Remove the notch that you have just cut.
Make a third cut from the side of the tree opposite your notch such that this cut is aimed two to three inches above the center of your notch. Cut straight through the tree, aiming just above the center of your notch. Just before this cut reaches the notch your tree should begin to fall in the direction of your notch. As the tree falls, move quickly away at a 45 degree angle opposite the direction of the fall.