Ground Cloth for a Pyramid…Need Advice

3 mil polyethelene plastic is good – maybe 2 oz / square yard – a little noisy – cheap – probably lasts only a few trips.

1.1 oz silnylon (1.4 oz with coating) isn't totally waterproof – okay for a tent but if you are touching the inside surface, for example your sleeping bag is on it, it will soak through some.

If you coat it with mineral spirits/silicone caulk, it will be pretty waterproof, plus you won't slip around on it. Maybe 3 parts spirits to 1 part silicone. Clear caulk from hardware store works fine.

I did this on my bivy and have used it at least 50 nights. It started peeling off the bottom after a few nights – don't do this. The top surface that I put my air mattress against has held up fine.

Hopefully not too much of a hijack of this thread, as some earlier comments related —
I just did a 3-day snowshoe trip where I slept under a tarp on snow/ice. I.e., packed down slick snow, virtually ice, I guess, temperature right around freezing.

My polycro groundcloth was useless, as even on very level ground it was sliding around a lot, quite frictionless. I had two 1/8" GG ccf pads to combine with my inflatable, so fortunately was able to put one of those under the inflatable to keep it from sliding.

I'm speculating that I should be using tyvek as a groundcloth when tarp camping on snow in future? Most winter camping I've done in the past has been with a floored tent, so this was a new one on me.

TIA !

I used tyvek last winter in my MYOG pyramid. It was about 33 degrees, so the floor was a mixture of slush and mud, but the tyvek kept me dry. It was on a fairly level spot, so I did not slide around, but it is MUCH less slippery than silnylon. (I have used both in the past)

When I originally posted this thread, I was pretty confident in going with tyvek because it was the cheaper option. Now that I am pursuing MYOG, I am now re-considering silnylon.

Is there any way in making silnylon less slippery? I was hoping there would be some kind of liquid or some method in adding friction to the material. The only other idea I had was to use rocks to prevent me from slipping around when I have to choose a not so level place to sleep. Waking up to realize that you are spooning your dad or friend is kind of awkward. :)

After I put a layer of silicone/mineral spirits (1:4) on silnylon it is no longer slippery, almost sticky. When I put it on the side that's against the rocks it rubbed off after a while. The side I sleep on has held up pretty good after maybe 100 nights.

Permatex Flowable Silicone Window sealer is supposed to be better, but I haven't tried it and don't know if you could cover a groundcloth with it.

I bought some spray in a can from REI many years ago to spray on things to make them less slippery.