I bring a footprint most of the time and use it about half the time. I put it under the tent. Sometimes if it is wet, I'll use footprint to cover the bike instead and sometimes I just don't put it under the tent.

As far as thorns go, I've had pretty good experience avoiding them until went to Africa with TDA. There I ended up puncturing my thermarest camping on thorns. A few factors made that harder (1) there were many of us on the trip and I was one of the slower riders, so I didn't always get as large a choice of where to put my tent (2) some places had a lot of thorns, more than I've encountered in North America. I was better than average on thorns with my tires, but still ended up camping on them occasionally - or tracking them into my tent on my shoes. Having a footprint under the tent didn't do much to stop those thorns.

Your answer will depend much on your camping habits. If you camp in pounded and depressed areas (as found in many campgrounds), you need to be very careful about a ground cloth. If you camp on well-drained higher ground (like much "dispersed" camping on public land), you don't need one at all.

I haven't carried one in over ten years, and the two tents I've used in that time frame, both with very light silnylon floors, saw hundreds of nights of use, many of those in desert and high rocky tundra, and never had floor damage. And after I learned to identify good campsites, I never got wet.

Of course you can carry a heavy sheet and not worry about it. But sometimes it's a matter of substituting care and experience for gear.

With the tents I use, I'd rather deal with a single dirty wet tent than a dirty wet ground cloth plus a wet tent--one less wet thing to pack and dry out later.

So, this summer when I camp in thorn country, to protect my Thermarest I should leave my Thermarest at home and instead bring a non-inflatable closed cell pad? I planned to bring the regular foot print for the tent instead of something thinner.

I know a sharp thorn when oriented in exactly the right direction will puncture virtually anything, but I was hoping that one additional layer of something would be pretty good insurance.

I guess that would be one option, but isn't what I do. I just am careful where I camp. I have done the Southern Tier, followed the Santa Fe Trail, toured the southern half of the Sierra Cascades route, done a dirt road tour in Colorado among other trips, and done some backpacking in the Sierras all without a single puncture to my Thermarest NeoAir. I used no ground sheet and on a lot of that I was using a light bivy. I do frequently sleep on improved surfaces like in road side picnic areas or pavilions, but I also camp on dirt, rock, or grass quite frequently.

On the Trans America (my first tour) I did get a puncture (or maybe more than one, I forget) in my Thermarest, but at that point I didn't know what goat head thorns were. I was using a pretty heavy duty ground cloth at that time. What I take from that is that care in choosing where you put your tent or bivy is way more important for avoiding pad punctures than whether you use a groundcloth.

Worst case patching a thorn hole in a Thermarest isn't a big deal other than that you will probably wind up sleeping with a flat pad one night unless you get up and patch it during the night.

If you absolutely must camp on top of thorns, a half length NeoAir on top of a foam pad might be your best bet if you want more comfort than just the foam pad.

That reminds me... I didn't mention it but one reason I have had no problems with my tent floors is probably that I never wear my shoes in the tent. I step out of them on the way in and into the on the way out.

Also I typically do not crawl or step directly on the tent floor. I usually blow up the pad outside then place it and the sleeping bag from outside. When I climb in I am usually ready to either read or sleep, so I crawl right onto the pad and settle in for the night. The exception is rainy weather when I may inflate the pad while I am in the tent. I do sometimes deflate the pad before I climb out though.

These days I most often use a really light bivy instead of the tent so any traffic directly on the floor without a pad is completely eliminated even in rainy weather. The pad typically stays in the bivy, when packing, unpacking, or carrying the bivy on the bike.

Thanks.

You are welcome.

One other thing that I neglected to mention. If you do not already know what goat head plants look like and where they grow, look at some pictures on line. The plants these thorns come from look pretty harmless, small and low lying, often a just little green in the cracks in the pavement. Also once on tour pay attention to where you find them. As you get more and more familiar with them you will get better at avoiding them both your sleeping pad and your tires. In goat head country check your tires for thorns every time you pull off of the pavement before getting underway again.

In US, even in thorn country, I would still bring a Thermarest. Next time in Africa, I would not bring a Thermarest.

The article is wrong. That's the most idiotic thing I've ever heard about tents. Putting the ground sheet inside the tent is like putting on a condom after finishing sex. By then it's too late. The ground sheet is there to protect your tent floor from punctures. Your tent floor is either waterproof or not. There are no degrees of waterproofness. If it's waterproof, you can set up your tent in a shallow pond and stay dry. If it's not waterproof, you'll get wet no matter how you set it up. Seam seal your floor before your trip. I've woken up with part of my tent submerged in a puddle on numerous occasions and I've never gotten wet.

A ground sheet will not protect your tent or your matt from goatheads. If your area has hazardous plants, inspect your site before pitching your tent.

There actually are. Different fabrics have different allowable hydrostatic head figures. Many use shelters made of newer silnylon fabric which is "waterproof" in falling rain, but not under high hydrostatic head, like body weight on a tent floor. Just something for Tarptent users to be aware of.

Here's a sample quote from a tent manufacturer:

The measure of hydrostatic head (or height of water column) up to which the fabric will remain watertight. The minimum specified by UK and European norms is 1500 mm and the majority of tents offer a hydrostatic head in the 1500–3000 mm range (which is adequate for most applications). The exceptionally high 7000 mm offered by crux tents means not only greater water-resistance but also greater resistance to UV, ensuring our tents a longer life.