Tarps & Bashas

• Background
• Tarp Design
•    Flat tarp / Basha / Hoochie
•    Flat tarp with beak
•    Shaped tarps
• When is a tarp a tent?
• Fabric
• Knots

Background

When I started to look seriously at the weight of my shelter I went back to examine the fundamentals of what I wanted from a shelter (ignoring issues of comfort):

• Something to protect me from the rain (and wind).
• Something that I can use in a variety of terrains.
• Something that is light.

I also had an additional rule that it must be significantly lighter and more flexible than my existing 1.6Kg 1-2 Man Saunders bacpacker tent which although a little old now is still an excellent weight.

As part of my research then obviously I looked at what went on with tarps in the USA and also at the 'standard issue' field kit for the modern army.

Now in the USA tarps are a massive part of the outdoor scene especially on the longer trails. Clearly there are people who use tarps in all sorts of rough weather including storms and snow. So, at first glance it would appear that tarps could also work in the UK.

The other part of my research was to look at army field kit. In the UK standard items for ground troops are a smallish tarp and/or a bivi bag. This is also true for most european armies and also for most areas of conflit. Obviously, the tarp and/or bivi then should be viable for most conditions that I would expect to meet if I was willing to forgo the luxury of a tent in return for the saving in weight and an increase in flexibility. The only thing left for me to do was to try one out. Read more about using tarps in the UK.

Tarp Design

There are a huge variety of different types of tarps and a range of sizes. The simplest tarp is just a big flat sheet of fabric and the most complex look strangely like tents. All of these design variations are trying to address different practical issues. The simplest way to explore them is to look at each of the basic designs in turn.

Flat Tarp or Basha

This is the 'classic' tarp. A large flat piece of waterproof fabric with eyeles or loops along all the edges. It is also I think one of my personal favourites and the one that I tend to use most.

It's main benefit is that you can pitch it just about anywhere. I personally like to string one up between two trees and use it as a 'roof'. This gives me acres of space providing that it is not too draughty and that there is not a lot of rain.

If there is a lot of rain around then typically a flat tarp is pitched close to the ground like a very low and flat tent. It is the most storm-proof configuration.

If you know that the wind and the rain are only going to come from certain directions then you can pitch it into more of a lean-to with one edge pegged to the ground and the opposite edge supported by poles. This will keep you dry unless the wind changes direction. You can read more about UK use here.

The major drawback of a flat tarp is I think bugs. If their are midges around you may well need some sort of net. Then you are into the territory that the net and the tarp might weigh as much as a tent. I tend to use a very small net that is big enough for my head and shoulders or use a net that is built into a bivi bag. Alternatively I simply pitch where there are no midges.

Flat Tarp with Beaks (Ray-Way Tarp, Henry Shires TarpTent Etc)

Clearly, the flat tarp is very flexible in where and how you can use it but even with some of the more creative pitchings you are still going to be open to the elements somewhat. In particular to wind. Now with the flat tarp, even when the sides are pinned down low the front and the back is still going to be open. If there is driving rain then some will reach inside some of the tarp. An efficient way to stop this is to use a beak.

I modified the tarp above to add a beak onto the front and the rear of the tarp. The rear beak is a 'standard' beak that can be rolled back when not in use or pitched taught regardless of the angle of the tarp. I have modified the beak by adding a tension system so that I can always remove slack.

The front beak is slightly different and experimental (complete with chalk marks!) and has no in-built angle but instead has a tension system that is rather like a boot-lace. This allows me to get the beak taught at any angle that I want and have no slack in it. In this picture it is pitched vertically and tied to the tent pole.

On this day it was very windy. The beaks make a huge difference. Without the beaks the tarp feels a little small lengthwise because the weather can creep in at the ends. With both beaks in use the tarp feels huge. It had the effect of giving me at least 1-1.5M of 'extra' space simply because my feet can now go right to the end of the tarp with no need to worry about them getting wet.

The beaks mean that the tarp is even better at shedding the wind and reduces the draughts inside to almost nothing.

Make your own ultralight flat tarp...

Shaped Tarps - eg Go-Lite Lair

A completely flat tarp is wonderful in mild conditions but once you have to start pitching to protect against the weather then you begin to notice how much fabric there actually is and how much is covering the ground and not you or your kit. Likewise, in a wind you are aware of how much of a sail that you have if everything is not pitched tight and low.

The obvious answer then is to cut away all the 'wasted' fabric. This results in something like this (a Hike-Lite tarp that is similar to the Go-Lite Lair 1:

The front height is around 1M and the rear height is around 40cm. The ridge-line is more or less a caternary cut and it has been pitched with the rear into the wind.

It should be obvious that there is a lot less fabric in this tarp than there is in the flat tarp. A lot less floor-space is covered but it is still enough for one-person. At a weight of 300g/10.5oz it is a lot lighter than the flat 1.8Mx2.5M flat tarp which weighs in at 400+g and yet provides more head-room.

On the upside, the whole thing weighs a lot less and can be made more windproff. On the downside there is a lot less flexibility in how it can be used. The only practical pitches are now going to be a tall A-frame (shown) or a low A-frame. A classic high-pitched roof would not provide much protection for the feet.

If you took this basic shape and added beaks to it then you would have a very light stormproof tarp suitable for 1 person.

When is a tarp a tent?

When I was lying inside the tap with the new shiny beaks attached I couldn't help but notice that it looked strangely like a single-skin tent - the sort that I slept in as a kid. So, at some point then these magic beaks can become door-like and when I had pitched on this particular night this is exactly what I had done.

There are no hard and fast rules here but I would suggest that if the tarp can be pitched completely flat then it is a tarp. If the beaks or whatever they are called prevent that then it is perhaps a tent. If the tarp has a sewn-in groundsheet and netting and so on then I would suggest that it is most definitely a tent.

On this particular night with a strong wind blowing and the clouds moving in I was very glad of the tent-like properties. Without the beaks it was very windy. With them it was cosy.

For the record, a single-skin tent is no colder than a 'double' skin tent where the inner tent is largely mesh. Only if the inner tent is 100% fabric and not mesh will it actually be warmer.

Make your own ultralight tarp/tent...

Fabric

There are only two ways to make a tarp lighter - use less fabric and/or use lighter fabric.

You can use less fabric by being more creative in the shape so that the maximum amount of usable space is created for the minimum surface area. This will lead you towards cylinders and hexagonal box shapes - generally with tapers towards the rear.

The alternative (and often complementary) method is to use a very light fabric. In America this has been taken to extreme lengths.

One thing that you will notice is that some of the lightest tarps are being made from fabrics that were designed for things other than weather protection - typically spinnaker cloth.

It can be the case that the cloth chosen has low tear strengths and low rain resistance (Hydrostatic Head). This could be fine in some climates but would be far from ideal in exposed places - such as a hilltop.

If you are making your own kit then obviously you can choose the tradeoffs that you make and if you want the lightest of weight then something that is showerproof and will rip in a low wind will be OK.

My personal choices are to use 2oz PU Ripstop nylon for cheap-n-cheerful tarps that will wisthand the weather quite well. This fabric will typically weigh in at 60gsm in practice. Light but not ultralight.

For luxury, lightness and strength I will use Ripstop SilNylon which has a weight of 60gsm (typically) is 100% waterproof and is amazingly strong. It is also around 3 times the price of PU nylon.

I do plan to use Silnylon in at least one major project but I consider the stuff too expensive for protyping even if the weight is attractive.

Knots

Tarps are often used in places where tents are not used and they are ofent pitched in a much greater variety of ways.

In practice this means that most people who use tarps have a standard set of knots that they use to set them up. You can read all about the knots to use and the best choices of knots here.