View topic - Tent groundsheets. Inside or out?

I split the posts in this thread off of the thread regarding re-waterproofing a tent floor. Have at it!

-HikerNeil

I like to use a footprint made from typar that's the same size as the tent floor so rainwater doesn't run between the groundsheet and the tent. It's lightweight, waterproof and tough as nails.

Hey Roddy,

If the footprint is pressed flat against the ground underneath your tent floor, how do you keep water from running on top of the footprint during periods of heavy rain or on saturated ground?

Although the tent floor should be somewhat waterproof already if it's not damaged I've always been concerned about rainwater puddling up on the exposed edges and running over top of the footprint. I usually try to pick a high spot if the weather looks iffy but of course that's not always an option, pro's and con's.

You could always dig a 12" trench on the uphill side or even better yet a moat If that doesn't work then pound sticks into the ground about 10 or 12" high surrounding the campfire, dry your socks and crack that bottle of southern comfort you've been holding off on

I guess I like the protection it provides from rocks or roots actually damaging the floor and compromising it to leak, moisture wicking up or having dirt stuck to the floor during tear down. The smaller size is a little less cumbersome and lighter to pack. Another small advantage is that you can use the footprint as a template when chossing location at a site where there are lots of roots or limited space.

Did you ever have a footprint - a proper one, made for exactly your tent model? If so, you would've noticed that it is slightly smaller than the tent floor. Like the previous post said, there should be no EXPOSED edges of footprint, then it works well.

I didn't use a footprint until bought a new tent on Ebay and the seller included the footprint. I was frustrated that might've overpaid because of footprint that I didn't plan on. Now I can't imagine living without it - it's everything that Roddy says and more, protecting from abrasion and ground evaporation and a template and so on.

I too put in a vote for a proper sized footprint, like Alm said they should be just smaller than the floor. If care is chosen in tent site location so that no surface water is directed towards the tent, you will have no issue at all. Very rarely have I used a footprint even in pouring rain, where there is any moisture between it and the tent floor.

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-Jim-

"Paddle faster, I hear banjos!"

I cut and use an inside poly groundsheet from the very first time I get a new tent. I cut the groundsheet so it extends a few inches up all the walls. I usually use a "factory" groundsheet outside, mainly to cut down wear to the underside of the tent.

The inside groundsheet cuts wear from sand and stuff, and when taking down the tent, I can pull the groundsheet out with most of the dirt on it.

When we bought our first tent in the early 70s, the bottom was not waterproofed at all. By the time I found that out, I couldn't exchange it. I cut an outside groundcloth that I attached to the tent with clips, and an inside groundcloth that went a bit up the sides. It performed pretty well.

If you're in a downpour, only a proper inside groundcloth is going to help. Tent bottoms, even seam sealed, are just not boats.

ezwater, your idea of lining the tent with plastic is curious to me, because in 40 years of backcountry travel, this is the first I have heard of it. Not just my tents, but with all the others I have tripped with. Because poly does not breathe, would it not cause a lot of condensation and moisture between it an the tent bottom, especially if the floor is not that waterproof? How would you dry this out?

The only time I have ever had water in my tent (at least a tent of even half decent quality) was due to an error on my own part in pitching it, and I have been through many a rainstorm, snowstorm or the worst thing, sleet.

As well, I have spent quite a few nights in teepees and other shelters with no floor at all with no troubles. The key is how and where the tent is pitched, though I know there is the odd location that offers up little for options.

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-Jim-

"Paddle faster, I hear banjos!"

It doesn't add moisture to the tent floor. The inside of the tent is typically warmer than the ground. Moisture does not have a strong tendency to move against a heat gradient.

Cliff Jacobson and others have been public advocates of inside groundcloths for some time, even arguing that they are more important than outside groundcloths.

Incidentally, on drying tents out, obviously one tries to do that while packing other things, before packing the tent. I'm experimenting with putting the tent "loose" in a mesh bag. This works well for car camping, if the trunk has room, and may work for the canoe, if there's a space to put the mesh bag where it isn't sitting in the bilge and is out of the rain. I don't think it's good for tents to pack them tight as if one is going backpacking. It contributes to micro-growth, and to delamination.

Where most CCR readers paddle, trench digging is not welcome: it usually wrecks the site for fellow campers with different tent shape and size...

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“What is the good of having a nice house without a decent planet to put it on?” - Thoreau

I was only joking about that and agree with you ..besides I'd probably land up twisting an ankle in the damn thing after half a bottle or so

Time to ressurect the old innie vs outie debate? GUARANTEED to start an arguement and debate in any camping circle.

Tent Ground Sheets (used inside or outside the tent ?)
“Innies and Outies”

There are two schools of thought on the use of ground sheets with tents with sewn in floors. Both innies and outies have advantages over the other.

Innies (ground sheet inside the tent)
If the purpose of the ground sheet is to keep one's bedding dry, then the location of choice is INSIDE the tent. This is contrary to conventional wisdom, but it works and works well. The ground sheet should be LARGER than the tent footprint so that it curves up the inside wall of the tent by about 6 inches all around to form an inside bathtub.
Inside, it is protected from sharp sticks and rocks by the tent floor. You don't have to worry about dripping or running water finding the edge of an outside ground sheet and then running under your tent floor to wet your sleeping bag.
If your tent is brand new, has 100% waterproofed material in a bathtub seamless design and is pitched in a well draining, high point of land, then you might get lucky. But in the real world, your tent gets worn, waterproofed seams fail and you don’t always have a choice as to where you pitch your tent.
During one of those monsoonal downpours, even the highest, well draining tent sites can turn into a temporary swamp. The edges of the ground sheet inside the tent form the shape of a boat and will keep you nice and dry even though water is seeping in and around and through the bottom of the tent, which it WILL DO.
A flat ground sheet underneath your tent offers no protection against any level of water flowing towards or around your tent. In fact, it will help convey water to the center of it.

Outies (ground sheet outside and underneath the tent)
The only thing a ground sheet does better outside, under the tent floor, is to keep the outside of the tent floor clean. That should not be its primary purpose, but if your vanity insists that you do this, then by all means do so, but be aware that at some time in the future, in the middle of the night, you may wake up in a wet bed.
When the ground sheet needs repositioning, which they all will, if it’s OUTSIDE, then guess what ? You’ve got to go OUTSIDE in the rain to fix it. Not a smart idea is it ?
This outie thing probably got started by a mother admonishing her son to "keep your tent tidy and clean sonny!" For Pete’s sake, tents are washable!

Abrasion Protection
Some “outies” argue that the purpose of the ground sheet is to protect the tent floor and waterproof coating from abrasion and punctures from sharp sticks, roots or rocks. The waterproof coating on the tent floor fabric is on the INSIDE of the tent. Thus in order to protect the waterproof coating, any liner should be located INSIDE the tent to protect it from any scuffing and abrasion caused by the occupants INSIDE the tent. Tent floor base fabric is very tough and can stand up to a lot of exterior abuse. If a tent is pitched on something sharp enough to cut through the floor fabric, how can 4 mil plastic underneath the tent provide any puncture protection ?

Tyvek or Plastic ?
Many prefer Tyvek, but heavy plastic (4 mil) will do very well indeed. The choice is yours.

Double coverage ?
Some choose both innies and outies. This is quite similar to using two forms of birth control and if that's important to you or the fear of wetness is scary and the thought will ruin your day or night, then by all means consider carrying the extra, but unnecessary, weight of double protection.
Don't go just on my word, give them both a try in a real rain storm, vanity not withstanding, and tell me which works the best.

Well ... I was going to save that for a slow day in January, but now that you brought it up ...

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paddle4fun, it is obvious your post is based on opinion and not actual fact. This is an opinion not shared by the masses. For starters, this thread is the first reference I have seen to using a plastic sheet inside the tent, and secondly in the thousands of tent setups I have seen and slept in I have never seen it done once, yet have seen a footprint used many times.

I have never experienced any of the negative aspects you claim a footprint has. Could it be I am just lucky?

I have seen people foolishly use a tarp with the edges extending past the bottom of the tent, this really can't qualify as a proper footprint though.

Still trying to envision how a sheet of poly would work inside. What keeps it in place, as it would seem that moving about would bunch it up and tear at it. Does anyone have photos of this setup?

Also, if it is that much of a better idea to put one inside, why don't tent manufactures offer this solution instead of offering footprints? I know some of the better manufacturers put a fair bit of R&D into their products.

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-Jim-

"Paddle faster, I hear banjos!"

I use Mother Nature's Groundsheet, completely eliminates the innie vs outie debate!

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"What else could I do? I had no trade so I became a peddler" - Lazarus Greenberg 1915

I use a hammock....apparently it saves a great deal of confusion.