Slackline Express
Slacklining: Verb, The act of having an unbelievable amount of fun walking and doing tricks on a piece of webbing pulled tight between two points, also used as a form of meditation, physical and mental training.

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Slackline Webbing Wear

How worn is worn? When should you retire your slackline? What is safe? For a most part the world's answer for how long to use a slackline has always answered "use your best judgment", "untill it breaks" or the even less helpful suggestion of when it's "sketchy".

Webbing life span is for the most part the "elephant in the room no one talks about." All webbing retailers know that these conditions not only can but eventually will happen to all webbing due to use. However, almost none however are willing to give guidelines about replacing it. They want to make the initial sale and inspire confidence in the product without acknowledging that all nylon safety products have a shelf life of about 5-10 years even if they are unused, much less left out in the rain and sun for a few years with constant load of being stretched tight for a permanent slackline. We're trying to be a bit more realistic, a slackline under normal use can last up to 5 years after that it should be much replaced if not sooner depending on wear. In extreme cases webbing can be permanently damaged to an unsafe level in a single use.

If you encounter any of the "bad" examples and would like your line refurbished please Contact Us, we're glad to help you out and if we originally made the slackline we try to do repairs and refurbishments at a no-profit pricing. If you received a slackline from us with a mill flaw please contact us, we'll fix it at our cost ASAP. We do our best at finding them all but given the nature of some flaws, they may not be evident until the line is put into use.

Some of these examples have been obtained from our own testing, some donated from people in the field, some web was sent in from customers wanting their lines refurbished while a few examples have been created for our illustrational purposes.

Good webbing
Perfectly fine webbing with only a small number of fibers lifting from the weave.


This webbing has been slightly abraded by either incomplete locking off of a cam buckle or by a lack of padding on a tree. This webbing is still perfectly fine but pad those trees or pre-load those cam buckles


This is an example of fibers being pulled out from overfilling a ratchet. The tale-tell is the gouge/fiber pull only on one the edge of the webbing. This is where the webbing on the spool gets bound against the slide plate that locks into the gears on the ratchet. While this web is still good be careful, if you can get a pinky finger into it, you'll should scrap your web. Avoid doing this by using our Super Tensioning Add-on pack for classic or homemade kits or learn to use the Tensioning Widget that is already built into the Primo kit.


This is an example of what will eventually happen to webbing without padding on the tree slings. While still ok for casual use, I'd avoid using it on lines longer than 40 feet as the clumping goes pretty deep. This is definitely a grey area on judgment calls but I have to be honest, the prospect of getting snapped with a webbing "whip" with 1,000 lbs of tension on it is definitely not on my list of things I want to do. I'd consider swapping out the sling for normal use, for a low line with the kids playing on it, it may be fine but you should pad the line to prevent it from failing.


A massive gouge in the line caused by slamming it in a car door where the latch was. Sadly this line was trashed before it was used even once. Even if the tensile strength is still there for now it'll accumulate dirt and debris into the webbing weave and quickly reduce it's strength.


This is an obvious mill flaw, the weaving machine did not "close" the side edge of the weave and it is just falling apart. The unfortunately truth is these do leave the factory and the web often does not fall apart into an obvious defect until the line receives a load. It is the job of all slackers and climbers to diligently inspect their webbing. Something like this is obviously not safe, however it may look just fine until you put a load on it or actually closely inspect the webbing.


This example too is a serious flaw from the production mill. The entire roll looked perfectly fine but about 200 feet in we found this. This is why you must inspect the entire length of your webbing before putting it into use. This is an extreme example however much smaller mill flaws easily make it past quality control from the plant. We catch these non-woven patches in about every case of webbing we buy however we do our best to catch any defects before it makes it to the customer.


This is an example of a typical burn. This is pretty common for nighttime slacking at campsites when someone sets up a line next to a lantern. The line is significantly compromised and it is recommended that it be replaced. It could probably be ok for light duty use but melting damages webbing pretty bad as it shortens the fibers which then loads the webbing un-uniformly which leads to it shredding under load.

Obviously trash. This example has been melted through one side and partly into the other. It only took 3 seconds of contact with hot metal to do this.


A puncture wound from slinging a tree that had a barb wire fence anchored to it. The line is probably ok, but keep an eye on it to ensure the hole doesn't get worse. Taking a flame to this will help seal the tuft of fiber so it doesn't get worse over time.


Looks ok from this side however check out the back:

This is an excellent example of why we say padding your trees will make a difference. This is climb-spec webbing designed to take extra abrasion and this level of damage was attained after two weeks of daily use. While still usable it will eventually fail due to abrasion if the owner continued to use it without padding.

This will test your eyesight but if you look closely the tracer black dash in the middle is offset to one side and disappears. This is a mill flaw, but a very minor one. We'd usually try to avoid selling it, but strength wise it should be perfectly fine.


This mill flaw however isn't quite so innocent. This example was caught before put into production.


This is a new piece of webbing. If you are worried about it being good you obviously haven't checked out our force calculator. It should be good for 4,000 lb + of tensile load.


Yet another mill flaw. However, this one didn't show up until it had a load placed on it. It made a small "pop" noise as the webbing elongated once the person hopped on.

Again, a mill flaw. This time a lengthwise type of weave flaw. This is a less common flaw but still be cautious to check for it. Most likely the line is still fine.


Congratulations, you've gotten your line dirty. No worries, if you are paranoid about it you could Wash It.


This is why we say to pad your edges. Eventually it will snap. This was loaded over a brick column for a week or so, and yes it failed while in use. Thankfully no one was hurt.

Ah, this tests your eyes. Notice that the weave changes a bit, this is a very minor mill flaw. While the line is probably strong enough, best to not use it as it will wear prematurely and will have lost unknown amounts of strength.


Even smooth anchors can wear into webbing. This example was supplied by a missionary in Guatemala that mounted on a smooth round light pole for about 4 months. It was taken down every day but always put up in the exact same place. We were able to replace their slings and send them a Padding Pack and nearly a year later it shows no signs of abuse.


This is a trick, it may be new webbing but this time we soaked up some car battery acid with it, left it under the car battery for a month or two, then washed it off. I haven't load tested it, but it would probably break with only a thousand pounds or so as a rough guess. This is a reminder that nylon is susceptible to more than abrasion and flaws from the factory. It feels different to the touch but would be hard to identify if in the middle of a hundred feet of web.


UV Bleached webbing
Yet another trick, this time I found the sample in Joshua Tree National Park in the desert. This webbing looks new but it used to be yellow. It has been completely bleached from UV light. The underside of the sling was still yellow, although fainter than normal. It feels brittle to the touch and would probably break under less than five hundred pounds. All images and content has the rights reserved to Slackline Express LLC.
If you want to use our images, photos or text, please ask us first. If your lucky we might send you the hi-res original versions.