Always use arborist ropes for climbing trees, not ropes intended for rock climbing or caving. Rock climbing rope (dynamic rope) is very stretchy and designed to take climber falls. Caving rope is stiff and won’t take arborist knots.
Colors. Tree climbing ropes come in a variety of colors. Which color you choose is a matter of personal preference. For recreational climbing, bright ropes are easy to see, but the muted earth-tone ropes make the climber less obvious to people on the ground. Professional climbers choose the brightest colored ropes because they want to see where their rope is in the tree. They also want their ground workers to see it to avoid cutting it with a chainsaw or accidentally feeding a loose rope end into the jaws of a chipper, which can cause a fatal accident.
Size. Tree climbing (arborist) ropes come in different diameter sizes, from 10mm to 13mm.
The largest is ½ inch (13mm). This thicker rope is easier to grip than others, but it is also the heaviest.
The smaller diameter ropes range from 10 mm (single rope technique only) to 11.6 mm for traditional doubled or single rope technique. These ropes are lighter in weight, which makes them easier to carry. However, they are harder to grip with bare hands because the exterior sheath has a tighter weave, which makes them more slippery. Climbers who use a smaller diameter rope solve this problem by wearing latex coated gloves, which improve grip considerably. The smaller diameter ropes also work better with mechanical ascending devices that are so popular with the more experienced climbers.
Construction. Arborist rope is built using different types of weaves. The two main weaves are called braided or kernmantle. Which one you choose is based on personal preference. Choose a rope of at least 16-strand construction. Never use a rope with a twist construction, as it will make you spin the moment your feet leave the ground. Arborist rope is soft and flexible, which makes it possible to tie the special climbing knots needed to climb trees. Stiff ropes will not hold the knots.
Sheath. Tree climbing creates a lot of friction on rope, which causes the rope to melt or fuse. The result is a stiff, “crusty” outer layer which doesn’t hold the knots as well. So tree climbing ropes are built with a special outer layer designed to resist friction and heat.
Elasticity. Tree climbing rope should not be stretchy, because a stretchy rope causes the climber to bounce and use more energy to climb. Arborist rope is more “static” as compared to the more elastic “dynamic” rock climbing ropes. That’s why arborist rope is the standard for tree climbing.
Rope ends. It’s a good idea to buy a rope with one of its ends (never both ends) spliced. The spliced end allows climbers to go beyond doubled-rope technique to use a more advanced climbing system, such as the hitch pulley method or single rope technique, to improve efficiency and speed.
There are three kinds of spliced ends.
- Standard splice. This is a large loop (6-8 inches) spliced on the rope end. Some climbers like a larger loop to tie off the end.
- Tight-eye splice. This is a more compact eye favored by many climbers. It’s a bit more expensive because it’s harder to make.
- Sewed loop. This is an end that is sewed to create a loop. It's not as streamlined as the tight-eye splice, but it functions just as well as the other splices. It is sometimes less expensive because it is not as difficult to make up.
The length of rope you need is double the climbing height of the tree (150 feet of rope to climb 75 feet up). Start by buying a rope that is 150 feet long unless you are climbing shorter trees, such as 50-footers, where you can use a standard 120-foot rope. If you plan to climb taller trees in the future, purchase a second, longer rope of 200 feet.
Tree climbing ropes will last for years of recreational climbing use if cared for properly. If you are climbing daily for tree work, replace your rope every year (this is the current ANSI standard). The old rope should be cut up into short pieces so it is not usable.
Your climbing rope is your lifeline — it must not fail while you are climbing! Always pay attention to your rope. Inspect it visually and by running it through your fingers before, during, and after every climb. If you find a damaged section, cut the rope immediately with a knife to prevent further use. It is easy to forget about a damaged section, and this is a rope that you should never use again!