Recently, I've been getting some inquiries and comments about bathtub floors. Mostly in regards to our decision not to include one in the new Refuge tent. So I thought now would be a good time to discuss some of the pros and cons of floor style on various shelters.
It's always seemed to me that phrase "Ultralight Bathtub Floor" is an oxymoron. A bathtub floor serves two purposes. Double wall tents with small fly's located close to the tent body incorporate high bathtub floors. The high tub walls guard against splash from pounding rain landing on the breathable sidewalls. Bathtub floors provide a barrier to any unforeseen streams of runoff that occur during heavy rains. The flowing water simply gets diverted under the tent when encountering the bathtub.
In the olden days before the bathtub floors became common in tents, the solution was to dig a trench around the tent to divert the water flow. So measured against that history, bathtub floors have reduced camp labor and limit our impact on the environment. So in general they are a good thing.
First a little history. So bear with me. All tents owe their heritage to the tarp. First there were tarps then there were special purpose shaped tarps. These were followed by fully enclosed tents with floors. Most of the early tents were made from canvas or silk. They were large and single wall. Since they were constructed from breathable fabrics, condensation was never an issue. During rain storms, the fabric fibers would swell when wet thus blocking passage of water into the tent.
When coated nylon tents were introduced, we saw first see the use of an inner tent. Thus the creation of the double wall tent. The inner tent was needed to provide separation from the condensation that formed on the exterior tent wall. Along with the introduction of the inner tent, its floor was formed as a bathtub. Thus the creation of the modern double wall tent with bathtub floor.
Recently, ultralight tent designers went back to the well, the tarp, and create a new branch on the tent family tree. In essence to chart a different course from earlier designers. We first start with the basic tarp, shape it to make it easier to reliably setup then add some sidewall mesh to keep out flying insects. Since it's still basically a tarp, a ground cloth substitutes for a floor. With more people carrying hiking poles the complicated support structure can be discarded.
While neither a true tent or tarp, it is never the less; simple, light and effective. These simple shelters provide a large degree of security while still allowing more interaction with nature.
Their downside? Like a tarp, they require a bit more knowledge of where to be placed. Unless you want to go back to trenching your shelter, you need to avoid sites that become rivers or ponds when it rains. For long time tarp lovers this isn't a problem. People with years of placing their backpacking tent anywhere they want, sometimes have difficulty adjusting.
It wasn't long before desire for "enhancement" took hold. Floors were added to keep the creepy crawlies at bay. Vestibules were added because no backcountry tent is adequate without it's carport. Bathtub floors were added simply because their double wall cousins had them. So if double wall tents needed them, it stands to reason that they should be needed on single wall tents as well.
However, there is one factor that often overlooked when comparing one tent vs. another simply on a feature by feature basis. In this case, it's a clear understanding of the materials used to construct the floor. To keep ultralight tent ultralight, lighter fabrics are used. This is true for both the canopy and the floor. Unfortunately a floor made from 30D or 1.1 ounce silicone coated ripstop, does not, will not and cannot offer the same degree of water protection of your traditional tent floor constructed from 70D or 1.9 ounce (or heavier) taffeta.
When used in the canopy, these light fabrics compare well to heavier polyurethane coated fabrics. The silicone coating not only waterproofs the fabric, it actually strengthens the fabric fiber. This allows lighter fabrics with smaller fibers to be used. The downside, is that when a heavy force is applied, as is the case of someone sitting or kneeling on a floor, the light fibers can be spread apart, allowing water to penetrate.
Don't get me wrong. I think ultralight floors are great. Personally that's all I ever use. I simply treat this kind of a shelter just like I would a tarp when looking for a place to setup. I want to make sure there is proper drainage away from the shelter during a deluge.
So back to my original comment about ultralight bathtub floors being an oxymoron. Making bathtub floors out of light fabrics conveys a false sense of security. The very presence of a bathtub floor makes a statement, "I'm built for more extreme conditions". Yet it makes little sense to divert flowing water under the floor just so you can sit on it and force it up into your sleeping area.
When comparing tents and features try and avoid the trap of simply thinking that no bathtub floor is a bad and having one is good. Look at the whole floor and consider both the fabrics used and the floor style. Ask yourself what kinds of campsite do I like? How much time to I spend in site select to ensure I won't wake up in a lake? Do I want the tent to do all the work in protecting me, or am I willing to share some of the load?
Happy Backpacking!