Condensation and ground cloth use with tarp (Gatewood Cape)

IMHO, backyard tests are always effected by moisture from the grass. You create a nice little greenhouse when you put the shelter over the grass and it is warmer in there as the external air and the skin of the shelter cools. You will have condensation issues with any single wall shelter and ventilation is the only remedy. Raising the edge of the shelter is a good move. I would leave the door open unless it was raining.

I think you are right about using as large a ground sheet as possible. the area covered by the Gatewood is about 35sf and Tyvek starts to add up in weight. Polycro or window insulation film is a better bet to save weight. I like to have a ground sheet that I can roll the edges under, creating a low dam and allowing any runoff to go under the sheet. Water is thin, so you don't need much height :) Also, with the Gatewood, you are sleeping at the back, so having a full groundsheet keeps you and your sleeping gear cleaner as you crawl across the floor to get in, and you can lay your other gear out for storage without getting it wet or dirty. The large storage area is one of the real perks of the Gatewood for me.

Yeah, greenhouse is right! I have one of the GG poly groundcloths, so that should work just fine as a light solution, rolled up at the edges to fit just under the Gatewood. (And Tyvek is NOISY!!! Good thing I'm not a really early riser, or on my last trip I probably would have been shot by fellow campers for the noise I was making just trying to fold up my tent's Tyvek groundsheet!)

I hadn't thought of leaving the door open, but naturally, that makes complete sense (and is easy to close in case of rain).

Kristin –

run the Tyvek through one or two wash-dry cycles and it will "soften" and quiet down considerably! (I did mine while we still had a top-loading washer. Not sure how effective the process is if you have a front loader. Can't hurt to try though.)

Oh, thank you! I will definitely try that – it may very well save my sanity! :D

A front loader works just as well. "They" say mild soap and no bleach will work–air dry. I've never tried washing with soap.
The next time you get tyvek consider the 1443R stuff. It is about 2/3 the weight of house wrap and much softer. Available here amongst other places.

http://www.intothewind.com/shop/Fabric/Tyvek

I've been using it under my SMD Wild Oasis for two years–same piece.

Don

The moisture is in the air. It condenses on everything that gets cool, no matter what it is. It's not all associated with your body moisture or breath.

I have a vintage motorcycle that I leave outside. It gets water condensing INSIDE the engine which can be seen by the oil turning milky. This is inside a bolted-up closed engine.
Air gets in everywhere, and if it is loaded with humidity and the temps drop, it is going to condense on anything cool that it touches.
If you really want to avoid condensation, you have to keep the temperature of your quarters higher than the dew point. And that ain't happenin' under a tarp.

So, I think it's best to just get used to it.
Condensation happens, and it's natural whether you are there inside the tarp or not, and the air WILL condense it's moisture out when the temps drop below dew point.

That amount of condensation sounds normal when pitched over vegetation-covered ground. In my backyard, I get condensation on a flat tarp with edges pitched 12-24" off of the ground. It will also happen in high humidity over any other ground. I've never found a groundcloth to be any help, but it would probably work when the conditions are barely right for condensation.

You're right about the groundcloth being best when slightly smaller than the covered footprint, but that covered footprint varies with pitch height and wind-blown rain.

I switched to another shelter after I became annoyed with my bag footbox getting soaked in my mid (Golite Shangri-La 3) when pitched within 5" of the ground.

Maybe you could make a "foot wall" inner made of light, breathable DWR 1.1 oz nylon? The bottom is a little shorter length-wise than the foot end of your shelter and guys out to the corner guyline attachment points on your shelter. Or, maybe it stakes separately just inside the shelter. The top is triangular (or tapered?) and guys out with shock cord or just regular line with a cord lock to the inside top of your shelter somewhere.

You know, I think that if I decided to forego the bivy (would depend on bug situation), I'd honestly probably just stick my feet (in the quilt) inside my pack, or at least inside the bag liner. I did this on a recent wet trip, and my pack (ULA Circuit) came up past my knees…

I appreciate all the input – it really does come down to expectations, which is why I asked. If I expect to be dry with little condensation (say, because I've pitched a certain way and used a groundcloth, the ground isn't wet and it isn't raining), and I get really wet in the night, I'll be irritated. If I go in *expecting* to have some condensation regardless of pitch, etc., then I'll be in a much better frame of mind about it (and I'll likely go to bed with my feet in my pack and my bandana handy).