DIY lightweight ultralight Cuben Fiber Tarp

DIY: Two ounce cuben fiber tarp

I’m usually a pretty serious advocate of buying brand name gear when your life depends on it. Recently, however, I’ve needed things that are so specific for what I am doing that they simply aren’t marketable. Last year, I made gear to allow me to safely paddle a kayak from Key West to The Tortugas which required a sailcockpit cover, sea anchor, and outriggers among other things (click the links to see the designs). But recently, I’ve set my eye on a backpacking trip necessitating the lightest gear and have been seriously disappointed with the options currently on the market. I was very impressed with the light weight and affordability of my 7 ounce silnylon Integral Designs Siltarp 1 that I purchased last year. But I figured using a similar rectangle design with Cuben fiber instead of silnylon could drop that weight even further. I did some calculations and figured I could make a Cuben fiber tarp using ZPacks materials that weighed just 2 ounces.

So I ordered

  • Four linear yards of their .34 oz/sqyd fabric
  • Four strips of .51 oz/sqyd 1″ seam tape
  • One  6″circular adhesive reinforcement
  • Two 2.5″ X 2.5″ stick on loops
  • I also had some small grommets lying around from a previous project.

I first cut the fabric into a 54″ X 82″ sheet. In hindsight, I probably would have accepted another .1 ounces to make it 90″ long. But being 5’6″ fortunately allows me to carry a pretty small tarp. I then cut the 1″ tape in half, giving me two strips of 1/2″ tape. I lined every edge with this 1/2″ tape rolled over to prevent fraying on the edges.

Edge
Seam tape on the edges

After that I cut the circular reinforcement into fourths, and applied one of those to each corner. I decided to just apply to one side, figuring, despite being aesthetically less pleasing, it would definitely be the strongest part of the whole tarp.

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Reinforced corners
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The uncovered side

After that I added 1-gram grommets as close as I felt comfortable with to the edges. I didn’t want the edges to roll over with the grommet too centered and I didn’t want the grommet to rip out if it were too close to the edge. For the guylines I used G-Line 1 Polyester Dyneema Guyline Cord from Litetrail but it is apparently no longer available. The ZPacks 1.25mm Spectra cord will work just as well. I used ~1.5 meters per corner and ~2 meters for the ends. The plan is to have long guylines so I can tie the tarp between trees more often than not. That’ll give it more functional surface area and allow my only carrying two stakes to be much more practical. It ends up being ~10 grams of guyline cord.

I put the stick on loops centrally on the short sides to allow me to run a guyline through it and set up the tarp A-frame style using trekking poles. I’m switching to the collapsible Black Diamond Ultra distance trekking poles which doesn’t allow me to simply take the guyline through the hand loop on the trekking pole like I did before with my adjustable poles. What I’ll probably end up doing is using two more stick on loops at the correct height on my new poles and just running the guyline through there.

IMG_5172

The tarp ended up looking great. I managed to keep straight lines despite having less than ideal tools. I highly recommend using a rotary cutter to cut the fabric. Other than that there is no sewing involved and it takes just a few hours to make the whole tarp. It ends up costing ~$100, surprisingly high for a DIY project but still markedly less than a similar retail tarp.

While the length is easily adjusted simply by cutting the fabric longer, increasing the width would need double sided tape. While still stitch free, it would certainly add to the weight and possibly the fragility by adding another point of failure.

IMG_5166
72″ X 20″ Downmat for scale
IMG_5163
~22″ high ceiling

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Comparison to retail tarps (all weights are body, guylines, and 2 MSR carbon stakes):

Mine   3.1oz  $100

Zpacks   5.15oz   $185

Hyperlite tarp   7.1oz   $300

Mountain Laurel Designs Grace Tarp   5.5oz   $285

If you’re not interested in making your own tarp, Zpacks is definitely the way to go. They normally make their rectangular Cuben fiber tarps out of the heavier .51 oz material but they very likely would make one out of the lighter .34 oz material if you request it.

I hope this helps someone else interested in making a ridiculously lightweight tarp but at least at minimum it proves it can be done. Up next: ridiculously lightweight Cuben fiber rain jacket.

VERSION 2.0:

I made a new tarp and used Zpacks stick on loop for the corners instead of grommets. I also didn’t use tape reinforcement for the edges. Both of these adjustments make the tarp even easier to make, lighter, and I believe with the same durability.

Camp for the night
Version 2.0 in action

24 thoughts on “DIY: Two ounce cuben fiber tarp”

    1. It didn’t seem to make much of a difference to me at all! They held up great without the tape. They rolled up slightly on the edges (a couple mm) and I have one small tear about half an inch but the dyneema threads stopped it from spreading. Thanks for checking out my site!

  1. Hi Grayson,

    Thanks for all of your insights regarding the DIY’s and trips.

    I’m Yam, from Malaysia. I’d like to ask, is there any way that you could come up with another set of your tarp & shipped it to my country?

    Those materials are not available here. Plus, yours seems very, very reasonable. The costs can be followed suits.

    Thanks for your kind responses 🙂

    1. Hey Yam,

      Thanks for your interest! I apologize but I’m very busy now and will be unable to build another tarp for quite some time now. I recommend checking out Z-packs site and seeing if they’d be willing to put one together for you. It wouldn’t be as light as mine but it will still be very high quality. Otherwise you could attempt building one yourself from Z-packs material. Good luck and let me know how it works out!

  2. Greyson,
    Zpacks site says their stick on loops will not be strong enough for guy lines. Have you had any issues with your version 2 using only the stick on loops?

    1. Hey Phil

      I have not had any issues. I also use super thin guy lines and the tiny 1 gram terra nova stakes so it’s all pretty low strength stuff. I’m not sure what would give out first but I imagine the stakes would bend or pop out of the ground before the stick on loops tore.

  3. Hi Greyson,
    Great stuff! In your post you mention increasing the width by using two pieces taped together. I’m looking at doing this to make a 9×6. Do you think the double sided tape is necessary? I was assuming I’d be able to overlap the edges and using single sided tape, weld the two pieces to each-other on each side.

  4. Great write-up. In the first completed photo showing the ceiling height, the tarp looks really narrow. Is that still enough space to fit your gear and a sleeping bag + bivy sack under? I’m considering making version 2 of this for a 7-day trip along the JMT in September. Thanks.

    1. Hey Paul, it is very narrow. I usually set it up lean-to style though which gives you a lot more space but you’ll still get sprinkled on in most hard rains. For 7 days on the JMT I personally would feel totally comfortable with it considering it hardly rains and with those big days you’ll be happier with a lighter pack. I’m jealous! Enjoy your trip!

  5. Thanks so much for the post! I’m thinking about doing something similar, but with silpoly. I was curious, though, can you give more explanation to the circular adhesive tape you used? I can’t find anything similar online to buy. I can’t imagine Gorilla tape would work, but that’s the closest to what I’m finding to it.

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