When I go go car camping, I put a tarp under the tent (I do it cause my dad did it) but when I backpack, I don't. While searching for gear online I keep seeing footprints for tents. Is this just to keep moisture from seeping up through the floor? Because I don't seem to have this problem...what am I missing out on?
Some tent systems permit a lightweight configuration, using just the footprint, rainfly, and poles. The footprint is also used to protect the tent bottom, from rain when it is heavy enough to puddle and run, as well as scuffing and abuse the tent may sustain when pitched on certain surfaces.
A tarp or footprint can help keep the bottom clean to some extent also. It's easier to wash and clean a tarp than a tent.
I've been using a small tarp for my backpacking tent. Discovered a few days ago the manufacturer was now offering a footprint for it, so I ordered one.
Light weight tents have light weight floors. I use a footprint when I dont know the surface that I will be seting up the tent on. I dont want to repair the tent floor. That being said, I make my own. This is what I do. Go to the dollar store and buy one of those real cheap tarps And those tape on grommets. Take it out to the yard and stake it down. Set up your tent and fly over the top of it. Dont worry about the stakes going though the tarp. Stake them right though. With a sharpie draw out the area of the tent, rainfly and all. Take down the tent. Cut the tarp 6 inches inside the lines. This will keep the footprint under your tent/rainfly. Now at every corner where a stake is tape on one of those grommets, keeping the grommet close to the tarp. Now put your tent back up over the footprint. Your footprint should not be showing anywhere. Tie a string from the grommet to the nearest stake. And there it is. A perfect fitting footprint. If your tent has a porch, vestible, you got that covered too.
The direct answer to your question is this:
Footprints (and tarps under the tent) have 2 purposes. First and foremost is to reduce the wear and tear on the floor of the tent. Since it is on the ground, hence in contact with the sand/gravel/rocks/sticks, the tent floor gets by far the most wear of any part of the tent. All of the tents I have worn out have had the floor go first. UV does get to the fly and top of the tent, though with polyester flies (rather than nylon), that is less of a problem. For winter camping or camping on snow generally, the wear and tear factor is much less important (except for people who insist on wearing their crampons in the tent - yes, people really do that, and it punctures Thermarests, too)
Second, the footprint can also help prevent moisture from seeping through the tent floor, especially for an old tent with lots of wear on the floor. So it can extend the useful life of the tent. But, the footprint (whether a tarp as your father used to use, a homemade one, or a custom made one with a big name manufacturer's label on it) can not extend beyond the floor of the tent. Generally it should be about a half to full inch inside the tent's floor edge. Otherwise it acts as a collector of water, which will gather between the footprint and tent floor.
Some additional information - The name-brand, custom footprints are far too expensive, even if they are perfectly fitted to the tent, and even if they can be used with the fly to make for an ultralight tent (basically a tarp tent). While tarps will work, they are really too heavy except for car camping (especially the blue plastic tarps). Some people get Tyvek from construction sites for free. Tyvek is a synthetic material that is used as a vapor barrier for walls, particularly behind siding. However, it is slightly breathable to prevent moisture buildup. Hence, under a tent, with weight put on it, moisture seeps through. It works just fine on dry ground to protect against the sand/gravel/rocks/sticks/pine needles, but you will get condensation on wet ground.
Cheapest and easiest is to get a plastic "painter's drop cloth". These are 2 to 5 mil thick plastic sheets in various sizes. Best one for 2 to 3 person tents is the 9x12. You can cut this into 2 9x6 sheets. They are very light, completely waterproof, and last a long time. Want a custom fit? Pitch your tent and set it on the plastic (easiest with a self-standing tent, but you can do it with a pegged tent, too). Use a Sharpie to outline your tent's floor, then cut out your custom footprint an inch inside the outline. I find that the 3-mil plastic (about $2 for a 9x12 drop cloth) lasts about a year, so $1 per year (and I do a lot of camping). That's 20 or 30 years' worth of the plastic for the price of a custom footprint - and the clear polyethylene is recyclable, too when it starts developing holes and tearing.
Great points. Keeping the tent floor dry and protected is why I always used a tarp while car-camping but I never carried a tarp while backpacking because I always though it was overkill. I mostly hike to to moderate backpacking sites ~5 miles from the trail head. I'm getting out further than ever lately and looking to do some longer treks next year so I've been thinking it's time to go a little lighter weight and I think Ed's idea with just a rain fly and footprint might be the way to make my REI Half Dome even lighter.
I appreciate your tips. I like saving money. I even have some of that painters plastic laying around from painting my girlfriend's house.
Along with Bill's advice of making a home-made foot-print, his description of using Tyvek is great. The stuff is rugged and you can usually get it for FREE at construction sites, however as he said, they do no do well with wet and soggy terrain.
I know that I paid more for my MSR Hubba Hubba HP footprint than if I built my own (got mine for $15), and that the plastic tarp is lighter, I personally did not want to make my own and the brand name one appears more rugged than one I could make myself (especially for the price I got mine at...cheaper than most for new equipment).
I've been using a footprint with my Mountain Hardwear Skyview 1.5 since I got that tent about 10 years ago. Primarily my goal is to avoid damage to the tent floor on rough surfaces. I'd hope, also, that it would keep the tent floor dry ... though (the bottom of) the tent floor does still get damp in wet weather.
I recently bought a Big Agnes Copper Spur UL1. I got it from Mountains Plus, so a BA footprint was included with the tent purchase. Unfortunately that model is backordered.
I went on a camping trip right after receiving the tent ... and wasn't about to subject the super lightweight floor material of the Copper Spur to any ground surfaces. So I took the advice posted here previously by The OGBO and others, and made my own "footprint" out of medium weight plastic sheeting. As it turned out, I was able to use the plastic packing material in the shipping container the tent arrived in :).
I was pleased to see with this arrangement, the bottom of the tent stayed completely dry, even though it rained during the trip. The only real downside was the plastic sheeting, not having the grommet holes found on regular footprints, was really tough to hold in place while setting up the tent. I guess I could try some of those tape-on grommets someone else suggested. I'm tempted to do this and stick with the plastic even when my BA footprint arrives :). It keeps the tent floor dry, and even saves an ounce or two of pack weight !.
This may help. I have thrown this out on the site a few times...
I use a footprint all the time. I find the advantages outweigh the extra weight. :-) The only real complaint I have is the extra cost of a commercial one made to fit the tent. The one for my BA tent costs $50!!
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