Zpacks Hexamid Duplex slip-slidin’

I had this problem with my stratospire 2 and tyvek groundcloth… I stopped using the groundcloth but wondered how to remedy the problem. Since then I've had no issues with the floor of the tent being damaged without it and feel comfortable going wthout it saving the weight.

I am however considering a hexamid and with the high cost of cuben I wonder what others are experiencing with durabilty without a groundcloth, or how they remedy the slippage.

I have read that some people aren't using ground sheets. But we have all manner of roots, rocks and thorny vegetation that I feel would render a puncture fairly quickly.

The Tyvek wasn't slipping on the ground, so I think that while waiting for other responses I will dab some Silnet on a small piece of Tyvek to test its adhesion. I'd rather put the Silnet on the Tyvek than on the Cuben. After it has dried I will have to see if there is then adequate friction between the two materials.

As is, my carried pack weight (incl 2-day/1-night food and 20oz water bottle) is 13.5lbs, so I am not too worried about carrying the ground sheet. When I can scrape up some more shekels I think I will get a Cuben ground sheet, which will indeed save a few ounces.

I had this exact same problem with my SMD Lunar Duo… even a hair of a slope would send the floor sliding… and especially when there were 2 of us inside. And the same as you, I was afraid that eventually, the mesh would rip right off and the floor would just continue to slide out from under the tent… ok, maybe that is exaggerating… a little… or am I?

Anyway, keep in mind the floor on my LD was sil, which is times more slippery than cuben… however, I ended up putting a few strips of silnet on the bottom of the LD’s floor… when weight was applied, this did seem to do the trick as to keeping the floor in place, at least mostly. Regardless, this was the main reason that I ended up getting rid of the LD… I now prefer floors that will stake down at the corners… just my preference.

Also, for what it’s worth, I haven’t noticed as much slippage with cuben floors on polycro… even on slight slopes…

Thanks, Chad. I imagined that mine was not the first experience with this issue, but some of the search results indicated reports of no, or fewer and far less severe, problems with slippage with cuben compared to silnylon. The problem, then, must be the Cuben/Tyvek combination.

As for groundsheet material, I think I will stick with Tyvek for the time being because a lot of the feedback on White Blaze leaned toward the durability of Tyvek over polycro.

As far as I can tell, nobody has previously put the Silnet on the ground sheet (vs the tent floor) so I am anxious to see if it will work. I've put a test dab on a piece of Tyvek and will know more tomorrow when it has cured. If that works, I am definitely going to put some Silnet on the NeoAir.

A funny side story…

For some reason (maybe because it was relatively warm, about 58degF) the dog didn't want to lie on his yellow CCF pad (which had no slippage problems) so he kept sliding down the slope as well. He fidgeted quite a bit, but after a while he just gave up and when I awoke in the morning he was curled up in a ball against the foot of the tent with his head buried in the corner, hanging over the mesh. He was so comfortable he didn't want to get out of the tent.

Why not try using the Duplex without a ground sheet?

I don't understand the point of buying a tent with a floor material apparently so light you feel the need to use a groundsheet. I understand you are probably trying to protect your investment, but why not just get a more durable floor in the first place? Cuben is easy to repair with tape even if it gets any pinholes.

I carry a small length of repair tape so this is definitely a consideration.

What has been your experience with a cuben floor tent? The Duplex floor is the 1oz/yd variety, therefore comparatively heavy to the .74 and .51 stuff, but there are so many reports that Cuben is quite susceptible to abrasion. The floor of my Bibler Eldorado was a truck tire by comparison!

I am an experienced backpacker but a UL noob, so any suggestions are entertained. You are correct that the investment in this tent is a big factor. More importantly, I REALLY love the design of this shelter (bug protection – the gnats and flies were horrible! – and pitching ease, ingress/egress) and the space/weight ratio (gobs of room for the dog and me to spread out!), and I want it to last a long time.

Hey Bob is there a way to add some attachment to stake down the corners of the tent floor like Chad had mentioned. I know if you look through the accessories tab or materials tab on Zpacks web site they may sell something that can be attached to your floor then staked down.

Happy Hiking

Hi, Mike,

That thought actually occurred to me as I was creeping downslope the third or fourth time. But upon reflection it appears to me it will merely transfer the stress to a different point and still lead eventually to a failure. And I don't want to carry a couple more stakes.

Overnight I did some patch tests on Tyvek and Cuben using both Silnet and Seam Grip.

Neither Silnet nor Seam Grip stick to Tyvek, so that's out. Silnet doesn't stick to Cuben, but Seam Grip sticks very tenaciously. I crinkled it up very vigorously and then tried to scrape it off with my fingernail, but it didn't budge. Seam Grip it is.

So I did my best guesstimating and made 13 rows of Seam Grip dots across the outside of the tent floor, about 3 inches apart, in the area where shoulders and hips will put pressure on the grippy dots. To reduce the number of dots, the pattern is biased toward the end of the tent with the Zpacks label, so although the tent ends are identical, that will now be the head of the tent.

“dabs of Silnet”
I never got these techniques to work. After the 2nd or 3rd day on the trail, the silnet attracted dirt/powder which made it slippery again. Thus it’s only a useless added weight :(

“As for groundsheet material, I think I will stick with Tyvek for the time being because a lot of the feedback on White Blaze leaned toward the durability of Tyvek over polycro. ”

Polycro is tough stuff. It’s lighter and packs smaller than Tyvek.

“Why not try using the Duplex without a ground sheet? ”
A few reasons:
1. Everywhere I camp leaves residue that stains the tent. I keep my tents looking good.
2. It forces needles to pierce two barriers instead of one. It’s better to go through the cheap barrier. And you might clean your camp spot as good as possible but you’ll still miss that burr. Ouch.
3. The underside of the tent will collect condensation. It’s much easier to dry out the ground cloth on your backpack or at lunch than trying to dry out the whole tent.
4. Because of that condensation, and since you’re with a group, you need to quickly roll up that tent. Now the condensation permeates the whole tent and that night you find your whole tent damp. And it won’t dry since the humidity has set in.
5. While the tent underside is wet, it will attract a whole bunch of dirt that eventually turns to mud that’s easily transferred to your pack’s contents.

-Barry
-The mountains were made for tevas

Barry, I am doing a lot of short trips this year (1-3 nights) and a couple of medium ones (4-6 nights) so I should find out sooner or later if it is going to work. The dabs on the inside of my Stephenson tent's floor have been working well for quite a long time.

I will also give polycro a try at some point. Where is the best place to get it?

For the reasons you stated, I also like to use a groundsheet of some sort. Even some very thin polyethylene "painter's drop cloth" is better than nothing, IMO.

I am surprised that you did not find that the SilNet stuck very well to the cuben. Before ZPacks were taping the seams, they sent a tube of SilNet with the shelters so that the buyer could seal it themselves. I sealed my first Hexamid with a tube of SilNet and it did fine. I never did try SeamGrip on cuben though…

As for Polycro, you can pick up sheets from MLD or Gossamer Gear. As well, you can go to most hardware stores, or even Wal-Marts, and pick up the window shrink wrap kit's. They will both do well.

Also, I would try using polycro under it before putting sealer on the bottom of the cuben floor… I personally have not found slippage to be an issue with a cuben ground sheet on top of polycro.

Chad, I was also surprised that Silnet did not work and that Seam Grip did.

When I was doing the patch tests I tested with a small Cuben sack just as an afterthought, in case neither of them stuck well to Tyvek, which turned out to be the case. For the Tyvek patches, I tested with 2 pieces that were factory slick and 2 pieces that were crinkled/rumpled to see if that made a difference. It didn't.

I'm glad I decided to test the Cuben, because absent any other information I would have assumed the Silnet to be the choice, but it wasn't even close. Silnet is totally unacceptable – it peeled up in nothing flat, after a 10-hr cure! – and Seam Grip is great.

The tent is still spread out on the floor for a thorough cure of more than 24 hrs. Field test soon.

I am stumped as to why a ground cloth is necessary. I have been using a Zpacks Poncho/Ground Sheet without issue for the last 2 years. It is in 1.0oz cuben which has proven pretty tough. I carry cuben tape so I have no worries.

"I am stumped as to why a ground cloth is necessary"

Barry summed it up pretty well.

When I look at the various forums the opinions are all over the place on this, and I decided to go the more conservative route for now. I also figured that not-fer-nuthin' does Zpacks have the Tyvek ground sheets for sale.

Maybe some day I will change my attitude on this, when I get more experience as a UL packer. But my total pack weight – including food, filled 20oz water bottle, extra clothing, camera and tripod (and the ground sheet!) – was 13.5lbs, so it isn't as if it was a crushing load that desperately needed paring.

I have used the solo plus ground sheet many times by itself and found no slippage. Also never had a problem with holes from surface below ground sheet. That being said I still carry some cuben tape with me, as many things I own are Cuben.

Sold the ground sheet.

Bought a Duplex.

Wow seems like they have the same material as the ground sheet.

Why would I put a ground sheet under a ground sheet?

In regards to the slippage. Well we all can't have everything we want out of every material.

Night before last I was able to test-drive the Seam Grip treatment and it worked great. This was the first time I've been able to pitch the Duplex on a fairly flat piece of ground but even so the effect of the 3-inched spaced SG dabs was excellent – ZERO slip.

"I don't understand the point of buying a tent with a floor material apparently so light you feel the need to use a groundsheet. I understand you are probably trying to protect your investment, but why not just get a more durable floor in the first place?"

John Harper,
My thoughts exactly. I've never been a fan of pairing groundsheets with tents either. Seems quite silly to me actually, but I understand why people do it, which Barry already summarized.

Bob Moulder,
Cute dog. He seems to like that pose!

For you guys who don't use ground sheets, how do you go about removing the moisture, mud, leaves and grass from your tent floor before packing?

I really like the ease of simply shaking out the tyvek, which sheds about 95% of the nasties pretty quickly.

The same way I would with a ground sheet if I used one. Zip the zippers shut.

Fold duplex in half so only floor is showing. Netting and sides should be folded in. Now you have just your dirty floor showing. Close your eyes and shut your mouth and shake baby shake. (Don't ever shake a baby)

Sometimes I just find some grass and wipe it off or use my good old hands.

I then fold it the other way so inside and what dirt remains stays there so it is not getting everywhere in my pack.

I don't use stuff sacks for tents. I find that it really makes for awkward packing when storing things in a flat rectangular fashion. Which is how the Duplex is shaped. Why roll it if it sits flat in the bottom of my pack? Pack is waterproof, tent is as well. Do I need another bag if my other stuff is in bags inside a bag? A little dirt, even a few grams of dirt never hurt anyone. Unless it was in a deep cut or something :)

outdoors

Camped the last couple of nights with no groundsheet and it worked out fine.

We had great weather and there was very little moisture, so not much at all sticking to the bottom in the morning. Made a clothesline out of the food bag line, let it dry for a bit while airing out the quilt, and then dried it off a bit more with a cotton bandana.

Unpacked this afternoon at home for a thorough dry, but I always do this with any tent and sleeping bag even when using a groundsheet because a tiny amount of moisture can cause mold/mildew when storing.