So my new tent (thanks for the buying advice btw), came with it's own footprint. It's effectively the same material as the fly, which is the same material as the bag, which I punctured by simply dragging it up against some textured sheetrock.
That got me thinking about abrasion resistance. After this unintended experiment, it's clear that these fabrics have none.
So, having said all that, and having used Tyvek in the past, should we ditch the footprint in favor of a simple sheet of HDPE/Tyvek? I weighed the manufacturers footprint, and my tyvek -- they're exactly the same weight. The only downside to the Tyvek is the crinkling noises. Which dries faster? Lasts longer?
I use footprints and have had great luck with longevity, I've also had zero leaks. I use them in the winter to prevent the tent floor from freezing down. I'd rather tear up and fight with the footprint than the tent floor. Rare, but it can happen. I've had Sierra Designs and Big Agnes tents with their own footprints, but I recently purchased a cottage mfg. tent and have been using Polycro, better known as window insulation kit plastic. It's tough and weighs less than half of Tyvek, doesn't crinkle and isn't as slippery. I have used Tyvek under the new tent and as a ground cloth. Rather use the Polycro. You can wipe off the Polycro and it folds up to @ 1/3 the size Tyvek does.
FYI: Longevity is defined as 300 nights on one of my tents and the floor is still perfectly sealed. The fly is currently at Big Agnes getting a rip repaired, the tent body needed nothing. I expect and need tents to last for years.
Sometimes I'll take a footprint if I know I'll be camping in mud, but otherwise I don't bother. I always buy one with my tent, thinking that I'll use it to try the "fast pitch" thing that uses only the fly, footprint, and poles to save weight when bugs aren't an issue; somehow, I never get around to it.
Loc: Portland, OR
In my experience, if I take good care of my tent floor it will last fine without a footprint. The most vulnerable part of each tent I've owned has been the zipper on the door. When the zipper goes bad, the tent is more or less unsalvageable.
Loc: Central Illinois near Springfi...
I have never used a footprint under a tent floor. I have made some for floorless tents, though. There are some interesting questions about tent floors and footprints. If you have a floor, why do you need a footprint if the floor isn't defective? The thing that got me to thinking was a statement, I don't remember where I read it, that the tent floor fabric may lose its waterproofness when pressure is put on it. That is similar to the old idea that tent walls will leak if you touch them while they are wet. I wonder if this doesn't go back to the days before coated fabrics. I have never tried to put pressure on a modern coated fabric to see if water will come through, so I don't know that this is true. In any event, the question comes down to whether you want to protect the tent floor from abrasion and punctures or do you want to protect yourself from water leaks. A waterproof liner inside the tent on top of the floor will protect you from water leaks, a footprint won't. I'm not a big fan of polycro, but it seems that using that as a tent floor liner might be a good application. If you want to use Tyvek, which I'm not certain is really waterproof, you will likely have to seam it, since Kite Tyvek is only available in 60" width, as far as I am aware. There is Tyvek repair tape available, but I don't know how this would work for seaming. Housewrap is normally Typar and is heavier and crinklier. There is a Housewrap called BlockIt that is much softer and is available in 10' width. I had some and wanted to make a footprint for a floorless tent, but used all that I had in construction. I want to get some more, but at $100 a roll, I am in no hurry. The best thing is not to pitch the tent in a hole, but site choices don't always allow this. Window film might be a good approach for a safety backup barrier.
Loc: Central Illinois near Springfi...
I did a little more research on Tyvek. Tyvek Homewrap is available at some home stores and has a base weight of 1.8 Oz. per Sq, Yd. Typar is a different product made in a different way, but looks a lot like Tyvek. Tyvek Softwrap is a lighter weight product made for packaging materials. There are actually several different types of Softwrap and the base weight is 1.27 Oz. Per Sq. Yd. What I have found so far is available in 54 and 60" widths. Cut to length Tyvek is pretty pricey and still only 60" wide max. Hard Tyvek is the paperlike material used in envelopes and is different from Soft Tyvek, which is mostly used for packaging. Remnants of Tyvek are often available on eBay, but will require some time to sift through them to find something desirable at a decent price. Tyvek Tape is probably made from hard Tyvek. It may make good tieouts, but may not work very well for seaming. I've got a roll, but haven't tried it yet. Tyvek Flashing Tape is probably not usable since it has a Butyl Rubber adhesive. Tyvek is sold as waterproof breathable, not waterproof. The water penetration resistance quoted is quite high, but I don't know how well it really performs.
http://www.antigravitygear.com/shop/shelters-accessories/tyvek-ground-cloth-by-the-foot/ I buy rolls of Tyvek in 9' wide rolls. Go ahead and call me wrong, but I actually use house wrap for building. My Lightheart tent came with a Tyvek footprint that is the same as the house wrap. I suppose a cottage tent mfg. could get it wrong, too. It's cut in width, the length was left at 108" . Typar is heavier material. Polycro IS window insulation kit. I've found Tyvek to be waterproof, otherwise, I wouldn't put it over sheathing and leave it weather exposed for any length of time, whatsoever. I also use it as lumber covers and my piles stay nice and dry after thunderstorms and snow events. Obviously I do not follow the general trend of thought here, as I don't on almost every subject, so the original poster can take that into account when he decides to footprint or not.
I think it depends on where you pitch. For me in the Sierra Nevada, sharp, abrasive granite slabs and gravel are often the only option. The fact that my tent-bag punctured by dragging over textured sheetrock indicates granite would be a disaster.
I like the ideas of waterproofing the *top* of the tent floor too. Waterproofing seems to be the important feature, but if it's not abrasion resistant, it's not water proof imho.
I'll look for the window-insulation for my ultra-light stuff, but so far, I like the tyvek for water *and* abrasion resistance.
Loc: Central Illinois near Springfi...
Tyvek Homewap is available in 9' and 10' widths, but it is heavier than Tyvek Softwrap. Homewrap base weight is about 1.8 Oz. per Sq. Yd, roughly equivalent to 70d, 1.9 Oz. per Sq. Yd Nylon. Kite Tyvek or Softwrap, 14 series is lighter at 1.27 Oz. per Sq. Yd. You can certainly use Homewrap, but it is heavier. It's the Softwrap that I'm not seeing in wider pieces. I would imagine that they make it in wider widths, but Finding a place where an ordinary person can buy a short piece is not that simple. Quest Outfitters has the best price on Tyvek 14M that I have seen so far at $5.45/Yd. It's much more expensive than Homewrap per yard, but I don't need a hundred feet right now. I believe that everything that you have said is true, but that we are talking about different materials. DuPont makes a number of different Tyvek products and it's not easy to differentiate between them if you aren't in that business.
Loc: Central Illinois near Springfi...
Like I said earlier, I'm not a big fan of window film, but it could be a good choice here. My big gripe has to do with it's flimsiness and the difficulty of keeping it in one place after you lay it down. There are stick on Tyvek tieouts available that might work well with the window film. Tyvek Tape might be a good edge reinforcement. The biggest piece of window film that I recall seeing in the stores was around 5' X 7'. That's not enough for a single piece footprint in a big tent. It may well be available in bigger pieces, but I haven't seen them. It might be possible to join two pieces with the tape that comes with the film. You'd need a big table to stretch the film out on to make the seam. I'd like to have an 8' X 9' piece, if I could find one, but I haven't looked very hard, yet.
I use a groundcloth with any tarp or teepee shelter and under my "Platinum" edition BA Fly Creek because the floor fabric is simply too thin, and easily cut.
For floorless shelters I take a hunk of Neatsheet, a discontinued picnic blanket comprising two layers of soft Tyvek (or similar). It's comfortable to sleep on and has withstood moist ground. For my BA footprint I fashioned it from "kite Tyvek" bought through Amazon. This was based on a tip from someone on these forums--didn't know the stuff existed.
I have no idea the fabric unit weight/area but it's light and relatively soft, like jumpsuit Tyvek and not slippery like housewrap. Didn't bother trying to anchor it to the tent pole tips, but that would be ideal.
We currently use Tyvek, but have used the very thin plastic painters' tarps as well over the years. Yep, that granite will wear a hole in your tent. And I can show you the holes in our footprints to prove it...
But if I were always camping on dirt? I'd leave it at home.
Loc: Washington State, King County
I think most of what I have to say here has already been said, but perhaps a slightly different cant to it ... (?)
I generally use a polycro/window insulation ground cloth because on longer trips I'm just pitching my tent --- more. More dirt on the tent bottom. More chance of abrasive ground surfaces, though I do find that rare. But also more chance that I might find an opportunity to cowboy camp, in which case I want the polycro to throw my bag onto and keep my stuff out of the dirt.
One of the last comments was about the ground cloth not extending beyond the tent fly/tarp, and that's a definite, especially if your bathtub floor is no longer 100% waterproof. Since I use my ground cloth without the tent sometimes, I don't have it cut exactly to the size of my tent, so have to remember to tuck it in on rainy evenings. Probably not the best, but it works for me.
I find tyvek too heavy and bulky, though as it ages --- depending on the tyvek --- it can certainly get more flexible. I guess the flip side is that with something like polycro, the virtue of it being lightweight/low-mass is that you just don't expect any puncture resistance from it. It's tough stuff, carefully used I've had it last for months on trail, but the way it fails is you get a longish slice in it that grows, or sometimes several of those.
I think the folks that bring no footprint have a great deal of logic on their side; I just have old tents (not so sure how waterproof the floor is anymore), and I prefer to get my polycro muddy rather than my tent floor. And again, cowboy camping.
Hmm, and sometimes the ground cloth is handy when first pitching the tent. My eye will apparently never be calibrated enough to angle the tent to make it maximally level at a site, I always seem to have to lay down first and adjust it. Easier to do this with a ground cloth (always involving four rocks or pieces of gear with the polycro as even slight wind will ripple and move it).
Ah, and it's also an item I can dry out separately. In some conditions the tent floor can be quite wet in the morning, while the tent body is dried out from the breeze. In these conditions I can put my tent away fairly dry with little fuss, and shake/wring much of the water out of the polycro --- and dry that as an individual item at my leisure if I'm inclined to. So I guess there are multiple small benefits from this light piece of gear.