By the very nature of our sport, there will come a time when you’re faced with using a wet rope. Can you safely rappel on it? Can you lead on it? Will water permanently damage the rope? Instead of making an “educated guess” in the alpine, learn the basics here to guide your decisions in the field. We polled five leading rope companies to see what they had to say about the strength of a rope before, during, and after being exposed to water. Note: All info provided specifically regards nylon dynamic climbing ropes.
It is safe to rappel on a wet rope (dry-treated or not).
A wet rope is not dangerously weakened for rappelling compared with a dry rope. Static strength is most important when rappelling, and ropes can have up to a 30 percent strength loss there. However, when wet, it is possible to see as much as a 70 percent reduction in dynamic performance, which is important when taking a lead fall (see below).
A dry-treated rope can still freeze even though it doesn’t look or feel wet.
The goal of dry treatment is to prevent the rope’s nylon fibers from absorbing water, but a rope is a woven collection of yarns and fibers, so it’s possible for water to be suspended between the fibers of a rope, but not be absorbed. That suspended water can freeze and turn the rope into an unusable cord. This affects its ability to absorb impact in a lead fall.
If a nylon rope is dried properly, and there are no signs of abrasion in the sheath and/or core, strength and elasticity return to normal and can be used safely.
If there were any long-term effects of soaking and then drying ropes, rope manufacturers would not recommend washing them at all. However, the rope has more elongation and is more susceptible to abrasion when wet, which can reduce the cord's ability to absorb future impacts. So if it underwent any major trauma when wet, retiring the rope is recommended.
It is ok to fall on a wet rope.
Rope companies do not recommend falling on a wet rope, which may have its dynamic performance reduced by up to 70 percent when wet. Modern dry-treated ropes are a bit better, with dynamic performance reductions of about 40 percent, depending on the type of dry treatment. Any fall on a wet rope causes more damage, so its future performance (even when dried) is compromised.
A dry-treated rope can never get wet.
Correction: The goal of the drytreatment process is to prevent the rope’s nylon fibers from absorbing water for as long as possible, but with enough wear, age, and exposure to water, any rope will eventually get wet. This isn’t waterproof like your rain jacket; it’s more a treatment on individual fibers that keeps them from absorbing water like a sponge.
Your rope must be thoroughly soaked through to suffer dynamic strength reduction.
Tests have shown that just being splashed under a shower had comparable strength reduction to ropes that have been fully soaked; i.e., the amount of strength and performance loss is nearly equal for both a damp rope and a fully soaked rope.
Dry It: When drying a rope, keep these tips in mind. Avoid exposure to direct sunlight and never use a tumble dryer, or any artificial heat source, which can damage the fibers of the rope. It is best to loosely flake the rope (avoid stacking the coils on top of one another to eliminate the chance of mold) in a cool, dry, and well-ventilated place. Be sure to rotate the pile in standardized intervals to ensure uniform drying. A regular house fan on a low setting can expedite the drying process.