Rope goes 'bad' after 10 years even if stored? Really?

I am looking to climb my tree to do some pruning work up there. I have a new-looking nylon climbing rope that is about 25 - 30 years old. It has always been stored indoors and I rarely used it. I read that rope needs to be retired after 10 years. What's the reasoning behind this? Perhaps they tested ropes after 10 years and they lost a certain percentage of strength? I still find it hard to believe that nylon degrades like that over time. Your thoughts?

Having said that, 10mm rope sold on Ebay is really cheap. 65 feet for $23.89. Would you rely on rope sold on Ebay?

3300lbs Heavy Duty Climbing Rope Static Rock-Climbing Escape Rescue Cord 10MM

lots to digest here. To start off, yes nylon breaks down over time and this is proven. yes ropes lose strength over time (all though not more than maybe 10-20%). for rock climbers who are using ropes to fall on, you should be replacing a rope at 10 years - if it doesnt need to be retired before then for other reasons. I wouldnt trust ebay personally. people sell crap on there all of the time and have no idea what it is. another point is that climbing rope is generally "dynamic" or it will stretch when weighted by a certain percent. what you have there is static rope which could work but is not designed specifically for climbing. taking a huge fall on that could injure you. final thought: this rope sounds like it was picked up from home depot or amazon. no actual climbing rope has a title like that. 

my recommendation: dont use it. and call an arborist  

Think of it as “best by” date. Just like your can of beans is still edible a day after expiration date, the rope is still useable a day after 10 years.

Manufacturers have to pick a date to put on items. And they pick it with a good margin of safety. The quality of nylon deteriorates slowly, and 10 years is well within the margin of safety, which is what the manufacturers have to do.

But how much past the date is ok? There have been very limited studies done on old ropes (just anecdotes with a few old ropes, not the kind of testing that assures the safety of new ropes), and they are still able to catch the fall at 10 years, but they have lost some elasticity, so the falls would feel a lot stiffer.

Nobody has done enough testing to tell you about the 25-30year old rope.

But you aren’t planning to use it for lead falls. So the threshold of safety you need is a lot lower. You want to guess if you are within the safety margins? Bc any answer would be just that, guessing.

Just like with expired beans, nobody can stop you from using it yourself. If you serve it to others in a cafeteria, you’ll be in trouble. 

Nick A wrote:

I wouldnt trust ebay personally. people sell crap on there all of the time and have no idea what it is.

It's hard to find rope sold in short lengths. I'm only climbing up about 30 feet into this tree. Places like REI sell rope in lengths of 150 feet minimum.

I have tended to retire old soft goods but I am not super worried about exact years.    Good info from black diamond 

https://www.blackdiamondequipment.com/en_US/stories/experience-story-qc-lab-old-vs-new-gear-testing/

Pete Alexander wrote:

Would you rely on rope sold on Ebay?

No. 

Pete Alexander wrote:

It's hard to find rope sold in short lengths. I'm only climbing up about 30 feet into this tree. Places like REI sell rope in lengths of 150 feet minimum.

Still hurts hitting the ground from 30 feet. Be safe, not sorry. 

Pete Alexander wrote:

It's hard to find rope sold in short lengths. I'm only climbing up about 30 feet into this tree. Places like REI sell rope in lengths of 150 feet minimum.

Are there not any smaller gear shops in LA that have rope by the foot? I'd be super surprised if that was the case 

Pete Alexander wrote:

It's hard to find rope sold in short lengths. I'm only climbing up about 30 feet into this tree. Places like REI sell rope in lengths of 150 feet minimum.

many online stores sell rope by the foot:

Static 

https://www.backcountrygear.com/10-5-performance-static/

https://www.rei.com/product/179718/pmi-e-z-bend-sport-11-mm-non-dry-static-rope?sku=1797180001&store=67

Dynamic

https://store.high5adventure.org/products/dynamic-rope-unity-9mm-by-the-foot

https://www.riggingwarehouse.com/500-c3402-10-00000-maxim-7-16-green-yellow-apex-dynamic-climbing-rope-per-foot.html

Usually search for rope and sort by lowest price. The rope being sold by foot will have a ridiculously low price because it's showing the "by the foot" price 

Nick A wrote:

yes ropes lose strength over time (all though not more than maybe 10-20%).

What do you even think this sentence means?

You're literally claiming that the rope loses somewhere between 10% and 20% of its strength over time--how much time? 5 years? 500 years? And then you're saying... it just stops losing strength?

for rock climbers who are using ropes to fall on, you should be replacing a rope at 10 years

If a rope has only lost 20% of its strength (which is the most you've said it can lose) it's more than strong enough to catch climbing falls with a wide margin of error. So why are we replacing it, exactly?

You know you're not being graded, right? There's no benefit to guessing when you don't know the answer to the question.

EDIT, since I'm over my post limit: dave custer posted a link to this, which seems to indicate that the half-life of nylon is about 70 years. There are some caveats to that (most notably, their method of obtaining this number isn't actually by aging it, although they did correlate with "field-aged nylon" to verify the result isn't totally crazy). However, if we take that number at face value, we could ESTIMATE the strength of the rope by the half-life formula (won't bore you with the maths here) to get the strength at different times:

0 years = 100%

10 years = 90.5%

20 years = 82.0%

30 years = 74.3%

40 years = 67.3%

50 years = 61.0%

60 years = 55.2%

70 years = 50.0%

80 years = 45.3%

(Nylon climbing ropes started being used more in the 1940s, so it's very unlikely your rope is older than 80 years. :D)

Even assuming the experimental evidence is exactly correct (which it may not be), there are a bunch of reasons why this is VERY MUCH AN ESTIMATE (for example, the formula I used is decay via one process--decay via two processes is a different formula and we know that nylon actually decays via two processes, it's just that one dominates the other at temperatures below 21C, so the results shouldn't change much).

The 10 year "shelf-life" thing is a relic of industrial and military uses. They don't get to eyeball a 20 year old rope that's been stored well and decide its okay because all that gear is eliminated by calendar dates, whether it's dead or alive.

You, as an individual, have the choice to make a judgement call. 

Pete Alexander wrote:

I am looking to climb my tree to do some pruning work up there. I have a new-looking nylon climbing rope that is about 25 - 30 years old. It has always been stored indoors and I rarely used it. I read that rope needs to be retired after 10 years. What's the reasoning behind this? Perhaps they tested ropes after 10 years and they lost a certain percentage of strength? I still find it hard to believe that nylon degrades like that over time. Your thoughts?

Having said that, 10mm rope sold on Ebay is really cheap. 65 feet for $23.89. Would you rely on rope sold on Ebay?

3300lbs Heavy Duty Climbing Rope Static Rock-Climbing Escape Rescue Cord 10MM

The age of the rope is the least concerning thing about this post. Even if you have a safe climbing rope, it's pretty clear from the things that you're considering here, that you wouldn't know how to use a rope to prevent yourself from getting injured or killed. I'm not calling you stupid, I'm saying that pruning a tree is more difficult to do safely than it might look to you.

It sounds like you're just looking to save money and not have to pay an arborist. But arborism is a skill, and it's worth money. And importantly, it's a skill that you don't have. If you even survive, the likely hospital bills from attempting to do this without the necessary skills with be far more expensive than just paying an arborist to do it.

You can probably learn the necessary skills, but that's probably not worth it just to prune one tree, even if you're doing it every year.

TL;DR: It doesn't sound like you have the skills to do this, and it's probably not worth acquiring those skills. Just hire an arborist.

A 40 to 49 foot offcut of Sterling 7/16 nylon static rope is $35 plus shipping at https://rwrope.com/collections/rope/products/sterling-nylon-static-first-quality-shorts-7-16-in?variant=29560885772341

A 90 to 99 foot offcut of Sterling 7/16 HTP static is $74 plus shipping at https://rwrope.com/collections/rope/products/sterling-htp-static-first-quality-shorts-7-16-in?variant=29560646533173 

Yer gonna die

But it won't be from that rope.

David K wrote:

The age of the rope is the least concerning thing about this post. Even if you have a safe climbing rope, it's pretty clear from the things that you're considering here, that you wouldn't know how to use a rope to prevent yourself from getting injured or killed. I'm not calling you stupid, I'm saying that pruning a tree is more difficult to do safely than it might look to you.

It sounds like you're just looking to save money and not have to pay an arborist. But arborism is a skill, and it's worth money. And importantly, it's a skill that you don't have. If you even survive, the likely hospital bills from attempting to do this without the necessary skills with be far more expensive than just paying an arborist to do it.

You can probably learn the necessary skills, but that's probably not worth it just to prune one tree, even if you're doing it every year.

TL;DR: It doesn't sound like you have the skills to do this, and it's probably not worth acquiring those skills. Just hire an arborist.

I second this completely. I climbed a tree once to trim a branch a while ago, and luckily came away successful with no injuries. I had a bit of tree climbing instruction at this point - just enough to be dangerous and not realize it. Knowing a good bit more tree climbing now, I'm shocked at the fact that I didn't get hurt, and realize that anything serious would have left me stuck in the tree with no quick way to be rescued. Based on your questions, you seem to know less now than I did back then. Get an arborist to do the work; leave it to a professional. Having an answer to this question doesn't mean that I change my opinion on that, but it would be smart to consider: do you have any plan for getting safely back to the ground if you are injured by whatever hand saw you have (don't even think of taking a chainsaw up there) or knocked unconscious in the tree? If not, you really have no business doing whatever you're considering.

About the details of rope/nylon aging:

https://www.ioa.at/wp-content/uploads/2021/05/Walter_Siebert_Masterthesis_IOA.pdf

R. Bernstein, K.T. Gillen, Nylon 6.6 accelerating aging studies: II. Long-term thermal-oxidative and hydrolysis results, Polymer Degradation and Stability, 95, (2010), 1471-1479

https://www.sciencedirect.com/science/article/pii/S0141391010002636

dave custer wrote:

About the details of rope/nylon aging:

https://www.ioa.at/wp-content/uploads/2021/05/Walter_Siebert_Masterthesis_IOA.pdf

R. Bernstein, K.T. Gillen, Nylon 6.6 accelerating aging studies: II. Long-term thermal-oxidative and hydrolysis results, Polymer Degradation and Stability, 95, (2010), 1471-1479

https://www.sciencedirect.com/science/article/pii/S0141391010002636

The Siebert thesis is a good read, thanks for sharing this.  His data shows no loss in average strength for nylon over 40 years. The main conclusion seems to be:

Hypothesis 1: There is no limit of life time. Textiles can be used as long as other criteria come up. This is true for ropes and harnesses, false for webbing exposed to outdoors.

The Bernstein paper seems to back this up, with very little change in strength over 40 years for nylon field samples.

Pete Alexander wrote:

It's hard to find rope sold in short lengths. I'm only climbing up about 30 feet into this tree. Places like REI sell rope in lengths of 150 feet minimum.

REI does sell static line up to 11mm by the foot. 

I am an arborist. As others have so eloquently said, tree climbing is a difficult and complicated skill. I’d compare it to trad climbing for the sheer amount of knowledge, practice, and experience it takes to do it safely and KNOW why something is safe / not safe. The equipment is also totally different than in rock climbing (beefy static ropes and beefier hardware).

Homeowners and other non-arborists kill themselves on a surprisingly regular basis trying to prune their trees to save a buck. Here’s a fun list of accident reports to chew on. 

If you do decide to ignore all the advice given on here, my one pleading request is that you do not, under any circumstances, take a chainsaw into the tree with you. If you do, the odds of you dying are incredibly high. A nick with a chainsaw is a bleed-to-death wound almost every time when you’re tied up in a tree, not to mention what happens if you cut your rope. 

David K wrote:

What do you even think this sentence means?

You're literally claiming that the rope loses somewhere between 10% and 20% of its strength over time--how much time? 5 years? 500 years? And then you're saying... it just stops losing strength?

If a rope has only lost 20% of its strength (which is the most you've said it can lose) it's more than strong enough to catch climbing falls with a wide margin of error. So why are we replacing it, exactly?

You know you're not being graded, right? There's no benefit to guessing when you don't know the answer to the question.

EDIT, since I'm over my post limit: dave custer posted a link to this, which seems to indicate that the half-life of nylon is about 70 years. There are some caveats to that (most notably, their method of obtaining this number isn't actually by aging it, although they did correlate with "field-aged nylon" to verify the result isn't totally crazy). However, if we take that number at face value, we could ESTIMATE the strength of the rope by the half-life formula (won't bore you with the maths here) to get the strength at different times:

0 years = 100%

10 years = 90.5%

20 years = 82.0%

30 years = 74.3%

40 years = 67.3%

50 years = 61.0%

60 years = 55.2%

70 years = 50.0%

80 years = 45.3%

(Nylon climbing ropes started being used more in the 1940s, so it's very unlikely your rope is older than 80 years. :D)

Even assuming the experimental evidence is exactly correct (which it may not be), there are a bunch of reasons why this is VERY MUCH AN ESTIMATE (for example, the formula I used is decay via one process--decay via two processes is a different formula and we know that nylon actually decays via two processes, it's just that one dominates the other at temperatures below 21C, so the results shouldn't change much).

you are 100% correct. but OP stated the rope is less than 30 years old so i figured it most likely has not lost all of its strength (it does not just stop, bad wording)). was it an estimate yes. but OP is also not a climber, he is someone who wants to climb a tree. i suppose i should not spout estimates online, my bad. 

the main point here is OP has a old rope he wants to use as a safety line while climbing a tree. i would not recommend this at all. it also sounds like he is not a climber which means i would advise against this activity even more. 

Closing thoughts:

1)the rope is old. it means its not as strong as it once was. will it break on you? most likely not but your life may be on the line here.

2)an Arborist is a very skilled professional for a reason. just like a mechanic or plumber or electrician - we pay them for their expertise and they are insured

3) if you are climbing, you should get climbing specific rope. and by this i mean UIAA rated stuff. there was a post about how some person got a repackaged black diamond rope that was actually some cheap amazon death rope.

4) whatever you do decide to do, be safe and i would like to remind you that pruning some branches to save a couple hundred bucks is not worth death or serious injury.