THE MYTHS OF TARP DURABILITY
It is a truism in the lightweight community that modern high-tech materials are less durable than more traditional tarp materials such as nylon or polypro. Challenged by a fellow forum poster I decided to test this out with a little survey of tarp users here on the site. This post is my report based on the findings of that survey, and, while this is not truly a scientific study, I think there are some gems in here, both in terms of relative durability of different tarp materials, and development of best practice in how to care for our modern lightweight tarps.
SUMMARY FINDINGS
This survey dispels the myth that Cuben Fiber is less durable than other modern materials in tarp construction. In fact, Cuben Fiber performs comparably with more common SilNylon tarp materials, and is more durable than SpinnTex/Spinnaker materials in real world use.
Note: Comparison with traditional tarp materials such as nylon or poly was not possible in this survey, since the sample size for these materials was too small.
In my opinion, there are two other important findings in this research related to the behavioral drivers of durability in tarp use.
1. How To Pack Your Tarp
The survey asked two questions related to how users pack their tarps in their backpacks. First, we asked about stuffing, folding and rolling tarps prior to packing. Second we asked if the tarps was placed in the main backpack compartment, separate pack pocket or in a stuff sack or ziplock bag inside the backpack.
By combining the data on these two questions, it becomes clear that the best practice taught on the BPL Wilderness Skills courses (at least, on the one I attended) is absolutely correct – tarp users should stuff their tarps in the main pack area without using a stuff sack. This finding holds true for all tarp material types, and yields a damage rate of about half the average damage rate across all packing methods. Users who insist on using a stuff sack would be well-advised to carefully roll or fold their tarps before placing them in the sack, since stuffing a tarp into a stuff sack yields no benefit in terms of safety – in fact damage rates in the “stuff it in a stuff sack” group were slightly higher than the average across all packing methods. The “fold or roll it into a stuff sack” group yielded protection only slightly worse than the “stuff it loosely in my pack” group.
Which methods were most likely to lead to tarp damage? Surprisingly, the “stuff, fold or roll it into a separate pack pocket” groups were significantly worse than the other groups, implying that this method of packing tarps should be avoided.
2. Which Type of Pole To Use
The second significant finding of this survey was the relative safety provided by tarp poles versus trekking poles, and the relative lack of tarp protection provided by stick or tree hanging methods. Trekking pole use yielded about average damage rates. Users who use tarp poles to suspend their tarps showed an 11% damage rate, about half the damage rates for trekking pole users. Tree or stick hanging users had an increased damage rate (~30%). It is likely that this increase is due to the large proportion of hammock users, who show a higher likelihood of experiencing damage to their tarps than ground tarp users.
An Emerging Best Practice?
Best practice for tarp use, in terms of protecting your tarp from damage, would therefore be as follows:
1. Use the lightest material you can afford. Lightweight materials are comparable in terms of durability.
2. Carefully stuff your tarp into the main compartment of your pack versus rolling or folding it into your pack. If you must use a stuff sack, then you should roll or fold it into the stuff sack. Whenever possible, avoid using a separate pocket for your tarp.
3. Custom tarp poles for your tarp are a worthwhile investment in durability for your tarp. You should conduct a cost/weight/benefit assessment to determine if you would want to add tarp poles to you setup. If you choose not to add tarp poles, trekking poles are the next best thing. Sticks and tree hanging of tarps is are more damage-prone approaches.
Personally, I will be replacing my practice of rolling & rubber-banding my tarp in my pack to stuffing it in (just like Mike C! taught me). I already own a pair of carbon fiber tarp poles, but haven’t used them since I purchased my LT4 trekking poles last year. I think it is time for me to examine this practice and see if I can find a dual-use for these tarp poles to make it more desirable to bring them along.
I’ll let you know what I decide when the time comes. Cheers & happy trails!
James Patsalides.
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DETAILED FINDINGS
Tarp Use
Fully 25% of respondents have used their tarps for more than 30 days under the stars, about a half have used their tarps for between a week and a month under the stars. The remaining ¼ have used their tarps for less than 1 week. This reflects a pretty substantial body of knowledge on tarp usage, reflecting data from 1,000s of nights of usage by the BPL community.
Fig. 1: Tarp Use Experience
Fully 65% of tarp users use trekking poles to hold up their tarps. 22% report using no poles, about half of these respondents were hammock sleepers rather than ground sleepers. A small number of tarp users (7%) use custom or purchased tarp poles.
Fig. 2: Tarp Pole Choice
Tarp Types, Sizes & Weights
More than half of the tarps in use in our community are constructed of SilNylon, with Cuben Fiber being a close second with 29%, and SpinnTex or other Spinnaker materials in third place with 17%. The remaining 4% reflect all other tarp types (classified below as “Nylon/Poly”) reported in the survey. This makes comparison of modern to traditional materials impossible, since 96% of users in this survey used modern materials. However, comparison of the modern materials to one another is absolutely possible.
Fig. 3: Tarp Materials
On average, the weight of our tarps is in the 10-15 oz range, with fully 60% of the reported tarp weights being less than 15 oz. Roughly the same number (4%) of tarps were in each of the <5oz and >30oz categories.
Fig. 4: Tarp Weight
A little over half of the respondents reported using solo tarps, closely followed by 45% reporting on two person tarps, some used as solo since even these larger tarps are incredibly light. A small number (3%) of reported tarps were listed as “really large” or group tarps.
Fig. 5: Tarp Size
Combining these three data points, we can see that our average tarp weight by material and tarp size are as follows, we can see that Cuben Fiber is the lightest tarp material (averaging 7.1oz for solo), followed by Spinnaker/Spinntex materials (averaging 12.49oz for solo), silnylons (14.11oz for solo) and more traditional materials (28oz for solo) such as nylon or poly. Strangely, respondents using spinntex 2-person tarps reported a lighter weight than cuben 2-person tarps – this appears to be mostly driven by the high number of Gossamer Gear SpinnTwin tarps being used by respondents.
Fig. 6: Average Tarp Weights by Material and Size
Tarp Packing
A number of questions were asked on the topic of how users packed their tarps when backpacking. Almost half of users stuff their tarps in the packs in the morning, 30% fold, 13% roll, and 3% do some combination of folding & rolling.
Fig. 7: Tarp Packing Methods
But what do tarp users fold, stuff or roll their tarp into? Most users (58%) use some form of stuff sack for their tarp, with 34% placing their tarp loose in their pack (14%), either in the main compartment with their other gear, or in a separate pocket in the pack (20%). 3% use a ziplock to pack their tarp.
Fig. 8: Tarp Isolation Method
There is no discernable difference in the practice of rolling/folding/stuffing based on whether the user uses a stuff sack, separate pack pocket or carries their tarp loose in their pack. In other words, the decision to fold/roll or stuff is unrelated to the decision to use a stuff sack, pack pocket, or main pack space.
Frequency & Severity of Damage
Twenty-seven of the 121 tarps (22%) had experienced some kind of damage in the field, with only one tarp (<1%) having damage more than 1in in size.
Fig. 9: Frequency of Damage
Within those 27 damaged tarps, 25 users either opted not to repair their tarps, or were able to duct tape or sew their tarps in the field, with 2 tarps requiring repairs which could not be accomplished in the field.
Interestingly, the highest rates of damage were reported with Nylon/Poly tarps versus modern high tech materials, although the sample size was very small (n=5), so this should not be used as the basis for any significant conclusions. Within the modern high tech fabrics, Cuben Fiber and SilNylon performed similarly, with 20% or less damage rates, which SpinnTex/Spinnaker fabric performed worse with a 30% damage rate. The overall damage rate of 22% reflects the high percentage of SilNylon tarps included in the sample.
Fig. 10: Damage Rates by Tarp Material
Behavioral Drivers of Damage
In addition to the findings with respect to Spinntex/Spinnaker materials, it appears that two user choices are also drivers of damage to tarps by active tarp users.
Packing method is a driver of damage to tarps. The most damage-prone packing method is to stuff your tarp into a separate pack pocket, with a 55% damage rate amongst those users who pack their tarp in this way. Next worst is folding or rolling your tarp, either in your main pack or in a pack pocket (~30% damage rate in these circumstances). Stuffing your tarp into a stuff sack provides some protection for a tarp, but still has a 24% damage rate. The two methods providing the safest handling of tarps are stuffing your tarp loosely in your pack (11% damage rate) and folding/rolling it in a stuff sack (14% damage rate).
Choice of poles is also a driver of damage to tarps. Trekking poles are the method of choice for most users with a 23% damage rate amongst this population, tarp poles users are much less likely to experience damage to their tarps (11%) and hammock, tree or stick users are somewhat more likely to experience damage to their tarps (30%).
Fig. 11: Damage Rates by Pole Choice
Who Responded
The survey was posted on March 31, 2010 and data was collected from random posters until April 2, 2010. A total of 121 tarp users from the BPL community completed the survey, 46% of these respondents reported having over 10 years of backpacking experience, 20% having 5-10 years experience and 21% 1-5 years experience. Just one novice backpacker (with less than 1 year of experience) completed the survey. This is a pretty solid, experienced population and very likely reflects the average experience levels of BPL forum users.
Fig. 12: Backpacking Experience
Also note that over 80% of respondents classified themselves as either ultralight or lightweight backpackers, claiming (5 day) base weights between 5lbs and 20lbs.
Fig. 13: Approximate Base Weights for 5-day Backpacking Trip
