Which Side Up for Ground Sheets?

[HooKooDooKu]

For those that use the matching groundsheet from their tent's manufacturer, which side should face Up?

Of course SOME groundsheets will give you a clue because the groundsheet is designed to pitch the tent in "fast fly" mode (poles, fly, and groundsheet only). But there's plenty of groundsheets I've seen where the only "connector" is a simple grommet, and other connectors can easily be used "upside-down" and you not even realize it was upside-down"?

In terms of identifying the "sides" of a groundsheet, the most common things I've seen include:
1. Shiny Side - Many of the groundsheets I've seen have a shiner side... should that side face 'up' or 'down'?
2. Manufacturer's Tag - Every tent manufacturer's groundsheet I ever owned included a tag sewn into the lining such that it's visible from only one side of the groundsheet. Can't see for sure, but a few groundsheets I've looked at lately seem to include the 'tag' side on what should be the 'up' side... but I've never seen a groundsheet with a "this side up" label.
3. Seams - Some groundsheets I own have a seam, and the seam is taped. I would ASSUME that the taped side should be 'up' to protect the tape from the 'ground'.
4. Connectors - Already commented on those.

[TNhiker]

i go with the tag up side facing up................


and typically, after the first couple of times i use a footprint----there will be mud/dirt on the bottom..........so from then on, i put dirt side down......

[AfterParty]

I would say shiny side down.

[HooKooDooKu]

I would say shiny side down.
Sort of goes strait to my conflict and reason for asking this question...

I've already made the argument that if you have a taped seam, the taped side should be the 'up' side. I'll back that argument up with the fact that every tent or rain jacket I've ever owned with a taped seam always had the tape on the "inside", with the part of the groundsheet facing the ground obviously being considered the "outside".

But from what I recall last night while washing my groundsheet was that the shiny side was the same side as the taped side of the seam. So based on my statements regarding taped seams would suggest the shiny side should be "up".

[AfterParty]

I now see what your saying and idk

[rocketsocks]

Does it even matter, never gave it a second thought...or a first thought.

[Skyline]

Never been an issue for me as I've used either a generic groundcloth or tyvek in the past.

But I should think ... but don't really know ... that mud, dirt, etc. won't "stick" as easily to the shiny side. If so, shouldn't the shiny side go down?

[HooKooDooKu]

...mud, dirt, etc. won't "stick" as easily to the shiny side. If so, shouldn't the shiny side go down?
Sounds like a Good Point.

The only counter I can come up with would be a question of "wear"... does having the shiny/taped-seam side 'down' create faster wear on the groundsheet?

[Feral Bill]

I would try to avoid wear on the coated side (shiny?) by having it up.

[MtDoraDave]

If it's tyvek or similar house wrap, the printed side goes down. Water (supposedly) doesn't go through the printed side (which is why it faces out on houses), but does pass through the back side (allowing houses to "breath").
This way, you don't get puddles between your tent and your ground cloth - the water would seep through it into the ground, while not allowing the water in the ground to come back up to your tent.

[Leo L.]

If it's tyvek or similar house wrap, the printed side goes down. Water (supposedly) doesn't go through the printed side (which is why it faces out on houses), but does pass through the back side (allowing houses to "breath").
This way, you don't get puddles between your tent and your ground cloth - the water would seep through it into the ground, while not allowing the water in the ground to come back up to your tent.
Sorry to correct:
AFAIK the idea behind any of those products is, water drops are way, way bigger than moisture molecules. So the membrane is (1) coated with something water-repellent to make water on the outside form real drops (which are to big to enter through the tiny holes of the membrane), while (2) moisture from inside can pass through the very same tiny holes.
As soon as its too cold for the moisture and it comes below freezing, the whole process stops working. As well as it would not work if there is full-floating water on the inside.
Would be nice if these membranes would work as a "puddle one-way valve". We could build self-draining kayaks, for example.

[Abi]

I just looked at an REI one I still have in original package. Package states coated side up. (In line with theory that it will get scratched if facing down, causing water to come through)

[Tipi Walter]

This is sort of a needless topic unless you put your ground cloth inside the tent, otherwise what does it matter? It's my standard procedure to put my ground sheet inside and works well with my Hilleberg tent floors.

There are several advantages to this technique with the main one being having a dry place to live (a dry floor) when it would otherwise be wet after packing up a wet tent.

https://photos.smugmug.com/Backpack-2015-Trips-161/20-Days-on-Medicare/i-bBh4HBR/0/M/TRIP%20166%20032-M.jpg
Here's my setup using a cut to shape walmart-type tarp at around 10mil thick. I mark one side of the white tarp with a magic marker (barely visible in pic) and this is the side which always goes up because it always stays dry. The black floor is often wet (either due to condensation or packing up a drenched tent) and so the white sheet keeps this wetness away from my pad and bag and other gear. When striking camp the unmarked side of the white tarp is wet but not the side I use every night.

It's a good system as of course the ground cloth keeps my Thermarest pads from getting punctured (added layer of protection), and in case my tent floor ever leaks (rarely to never), all the water stays between the ground sheet and the floor.

Plus, when a ground sheet is placed under a tent it can sandwich puddles of water between the sheet and the tent floor and never drain. This can happen in a deluge when buckets of water cause ground sheeting, i.e. the mvt of rain water on the ground and into your vestibule and under your tent. Hammockers need not comment.

[Leo L.]

...
Here's my setup using a cut to shape walmart-type tarp at around 10mm thick...

Can you explain please: What is 10mm thick? The tarp?

[Tipi Walter]

Can you explain please: What is 10mm thick? The tarp?

The usual cheap walmart blue tarp is around 3 to 5 mil thick. My white tarp is 10-12 mil thick. The thicker the tarp the heavier it is but the more it resists thorns. A heavyweight 14 mil tarp will turn back a rose thorn. I know, I tested several in the field with . . . wait for it . . . rose thorns. Try these two ground cloth tests:

** See if a rose thorn or briar will poke thru the sheet.
** Water test: This is the test most ground cloths fail. Turn on water hose in backyard and create small pool in the grass. Place ground cloth on top of pool. Sit on top of ground sheet for 5 minutes and see if any water seeps thru. Most will leak. Try this test using your tent floor too. The best material I have found are poly tarps as in this link---(I like white because I can see stuff better on my tent floor)---
http://www.tarpsplus.com/ehitetarps.html


(http://www.tarpsplus.com/ehitetarps.html)

[Feral Bill]

1 mil is a thousanth of an inch, much less than a millimeter.

[HooKooDooKu]

This is sort of a needless topic unless you put your ground cloth inside the tent...
I would argue quite the opposite...

...that this topic is needless if you put your ground cloth inside the tent... because you remove issues such as wear because the tent now protects the ground sheet from wear and water and dirt collected from the ground.

[Tipi Walter]

I would argue quite the opposite...

...that this topic is needless if you put your ground cloth inside the tent... because you remove issues such as wear because the tent now protects the ground sheet from wear and water and dirt collected from the ground.

Missed my point. A ground cloth under the tent will get soaked no matter which side is up or down. Place tyvek on slushy wet snow and sit on it. Does it matter which side is up? And it surely doesn't matter with a poly tarp as both sides are equally waterproof. As noted, do the backyard water test on all fabrics and tent floors and see if any water seeps thru. Turn them over and see if it makes any difference. Probably not.

Which side of a ground cloth to use IS important when the sheet is placed inside the tent because as mentioned, the tent floor is often wet with condensation or after packing up a soaked tent and setting up the next day as all the fly water soaks the tent canopy (if a double wall) and gets the floor wet (certainly in a single wall). On these occasions I set up the tent, shake it thoroughly to dislodge canopy droplets onto floor, rag out floor puddles if any, AND THEN put my dry ground cloth (with the marked side up) onto the wet tent floor. Voila---a dry floor.

In other words, one side of my ground cloth stays wet, the other side dry---for the duration of the rainstorm and repeated camp setup.

[orthofingers]

If you ask DuPont which way Tyvek should go on a house, I believe they say to put the DuPont Tyvek writing facing out. Any building sciences person I've spoken with (and I have spoken with a few) says this is purely so the DuPont brand can be seen from the street and that functionally, it absolutely does not matter. Water vapor or water droplets can't read and don't know which side is out.

So, I say, under a tent, it doesn't matter.

[HooKooDooKu]

Missed my point...
So if I get your point(s)...
1. A ground cloth under a tent is useless [for protecting your tent from water].
2. Which side faces up doesn't mater at the start of your trip, but for the rest of the trip, that is now defined as the "dry" side and should always be placed "dry" side up.

[Tipi Walter]

So if I get your point(s)...
1. A ground cloth under a tent is useless [for protecting your tent from water].
2. Which side faces up doesn't mater at the start of your trip, but for the rest of the trip, that is now defined as the "dry" side and should always be placed "dry" side up.

Yes, in a deluge with heavy rain (in the Southeast mts of TN and NC) a ground cloth under a tent is worst than useless as it sandwiches puddles of water between the ground sheet and the tent floor.

Second point is correct but only if the ground cloth is used inside the tent, to take advantage of the dry side up.


https://www.youtube.com/watch?v=10L6Y1FCnno
Here is the scenario I am talking about. In a heavy rain with a tent all the water hits the tent fly in buckets and eventually if it's hard enough all this water falls off the tent roof and begins to move around on the ground outside of the tent and eventually under the tent vestibule and finally under the tent itself. This happens everywhere if it rains hard enough. Think buckets of rain during a one hour deluge.

My video example shows exactly what happens and how any outside ground cloth would get swamped with water and sandwich pools between the cloth and the tent floor with no place to drain. So I keep my ground cloth inside my tent.

Of course my tent floor has 7,000mm hydrostatic head with a 100 denier tent fabric---I consider it the best tent floor material on the market---and the driest tent I have ever used. (Hydrostatic head is the Seep Factor---proven by sitting atop a piece of fabric on soaked ground and seeing if any moisture seeps thru---it should not).

[Leo L.]

Thanks for clearing the mil vs. mm issue. My fault.

Honestly, I would rather place a groundsheet under the tent floor, to keep the (expensive) floor from wear as long as possible.
But my tenting experience it limited, and never had used a groundsheet at all.

[HooKooDooKu]

Honestly, I would rather place a groundsheet under the tent floor, to keep the (expensive) floor from wear as long as possible.
That's pretty much my attitude, especially since Tipi's plan is centered around camping when it's raining. But unlike Tipi (who is known around here for going out for weeks at a time), I'm mostly a weekend camper and simply delay my trips (when possible) when the weather forecast includes lots of rain.

[HooKooDooKu]

I'm going to wrap this thread up for now... I appreciate everyone's input.

Based on the initial question (when using a matching manufacture's ground sheet, which side should fact up), the answer by condenses would seem to be "shiny side up to prolong the life of the ground sheet".

Tipi has provided some good tangential information what would appear to be the best way to utilize a ground sheet when camping in wet weather (tangential because it's best implemented utilizing a thick ground sheet and therefore technically outside the scope of the initial question regarding manufacture's ground sheets).