Ultralight Backpacking Tarp

A trail staple: The ultralight tarp 

One of the most useful and adaptable pieces of  staple kit on the trail is an 'ultralight tarp', usually made from silicone impregnated nylon ( silnylon) or spinnaker nylon fabric impregnated with silicone. On almost all of my outdoor trips I take an ultralight tarp of one description or another. The one I use the most is a 295g silnylon tarp with 8 pegging points, ironically this is also the simplest and lowest cost tarp I own.  It is rectangular in shape, 1.5 metres wide and 2.7 metres long. On 'solo' trips the tarp teamed with a suitable inner nest becomes my only shelter, replacing the tent entirely. In a 'family' setting I do take a lightweight 3 to 4 man tent for sleeping in, usually a tipi for three, the tarp is taken in addition to the tent.

In the family or group setting the tent, acts as the bedroom, the tarp is used to store and dry wet gear and boots, or form an enlarged porch  to cook under in the rain or to throw up a quick lunch stop shelter or provide a groundsheet. In fact it is used so often I consider it as fundamental to comfort and well being on the trail during the day and at camp in the evening.

I try to carry  gear which serves several functions for a given weight of carry. At 295g, this piece of fabric more than earns its keep. In later posts we will look at some of the wider uses a tarp can be put to. In this post we will look at size selection, and then run through a daily run with a solo sized ultralight tarp acting as a primary shelter on the trail.

Tarps come in all shapes and sizes, and often I am asked about what size of tarp is best. Specifically I am referring in this article to backpacking tarps which may be used primarily as a shelter using trekking poles or environmental attachment points such as vegetation, rocks or fencing. If  I intend to use my tarp as a shelter on its own without any sort of inner nest or secondary protection from the elements, which may occur outside of bug season  I will take a slightly larger tarp, say 2.7m by 2.5m. If I am using a tarp in conjunction with a secondary form of protection such as a bug bivi, bivi bag, solid walled nest and so on I can take a smaller tarp.

The important thing with sizing is that at least one of the dimensions for a shelter tarp that is intended to provide protection from the elements whilst you sleep will need to be at least 70 to 80cm longer than your stretched out height. On this basis someone such as myself will need a 2.7 to 2.8 metre tarp. The overhang at each end keeps out the elements. I often see tarps being sold that are only 2.4m long, this is not long enough for anyone over 5' tall in my opinion.  At the other extreme I see tarps over 3 metres, a length of 3m or more provides a diminishing return and therefore becomes dead weight, you may also need as many as 16 pegs, and side pullouts to retain a taught pitch on a 3 metre width.

In terms of width, a single fabric width of around 138cm will work fine for a minimalist solo backpacker using either a low A frame, a flying A frame, or half pyramid type pitch. The smallest tarp I use however is 150cm by 2.7m.

There are several  methods of retaining privacy when using a tarp as a primary shelter say on a campsite. The most effective is by use of accessories such as using a solid walled inner nest, such as the Wrath Outdoor Jetstream, or by the addition of small beaks which close off the open ends. Alternatively, if the tarp is to be used without such accessories, creative use of the camp site landscape can work well - hedges, trees, walls., fences, anything to completely obscure the view from at least one direction is ideal provided the spot is sheltered and the open ended side of the tarp is not facing directly into the current wind direction.

In a wild setting privacy is much less of a consideration, in fact it is one of the best aspects of a tarp, the opportunity to see the landscape around. Some people find being able to see out is quite scary, but think of it this way; if there were something scuffling around outside, an animal for example would you rather know what it is or let your imagination run wild behind a tent wall?

Here set up as half pyramid, the bug bivi acts as a tub groundsheet. A great set up for food prep and camp chores as sitting headroom is provided. 

Upon arrival at my chosen campsite or wild camp I almost always set up a half pyramid with my 1.5m x 2.7m tarp setting a single pole at around 110cm. The open end of the tarp points away from the elements.I carry 8 lengths of  guy line to facilitate my pitch. I generally do not leave my guylines attached when I pack up at the end of my trip, but on the trail I do leave my hanked guylines attached. Check out my post on 'String Theory for Backpackers' for details of my guyline set up and the variety and use of knots for setting up a tarp. Some tarp users however use small line locks on the guys instead of the knots which I use, it does not matter which option is used really.

In midgie season I arrange my bug bivi underneath my tarp. The bivi has a sewn in 10cm tub groundsheet. Unzipping the bivi I place my sleeping mat, sleeping bag, and my spare clothing inside, and then zip it in. I sit on top of all this whilst prepping my meal, maintaining and mending kit etc. I prefer to set things up in this way initially as the half pyramid makes a weather resistant shelter, affords privacy from three sides but most importantly I can sit up straight out of the wind, rain or sun. I leave my camp set up like  this until maybe an hour before bed.


At this point I  rearrange the pitch into a fairly low A frame, with a pole length set at around 70cm.  The windward edge pegged close to the ground. All my spare gear goes back in my rucksack and I place this either as a pillow or at my feet. I pull up the apex ends of the bug bivi to form my bedroom, climb inside and zip up. I generally read, check next days route or listen to podcasts for a while unless there is a spectacular sunset or view in which case this offers all the entertainment I need. For warm humid dry nights I pitch the tarp higher to allow plenty of air flow. In the UK this does not occur very often admittedly.

This A frame is being flown very high to provide lots of air flow, ideal to get everything bone dry for a few minutes before camp is struck, or for warmer nights on the trail.  Dropping the apex of the bug bivi would provide sitting headroom to cook or eat.  

Come the morning depending upon the conditions experienced in the night the tarp will either be bone dry or have an amount of condensation inside and out. If condensation is present then it is best to avoid touching the inside of the tarp or shaking it too much. In this event I would unzip my bug bivi via the top zip, and carefully wipe any excess within arms reach with a small absorbent cloth I keep for just such a purpose, this cannot be done with a tent, so you have to wait a lot longer for condensation to evaporate.  I then climb out. If the weather is dry and not too windy I generally then increase the pole height to around 100cm at one end and extend the front and middle guys accordingly. I can then sit cross legged at this end to prep breakfast, wash and generally get organised.  If its raining I pack up my sleeping bag, mat and other gear into my rucksack before even climbing out of my bug bivi, this way ensuring it all stays as dry as possible. Going in and out into the rain is the best way to soak gear. I then get dressed into my waterproof  before climbing out into the weather. I next pack up my bug bivi / groundsheet and then finally the tarp. The tarp is shaken and stuffed into a ruck sack side pocket, once I have hanked the guylines. A quick cereal bar and then I hit the trail.

I don't bother sitting around at camp if its raining, I may lay in bed for a little longer in the hope of it stopping, but if this isn't going to happen I prefer to get up and set off along the trail. If I am lucky the rain will stop after an hour or two along the trail and I can then stop for a while to dry the tarp and eat again. If its still raining by lunch I set up the tarp as a half pyramid and sit under this for lunch. Shaking off the excess water and packing it away into the pocket again afterwards. I do stop for meals. I find keeping a routine like this allows me to sit and watch the world a bit, which I enjoy, and check my route.

The above describes a typical set of scenarios, but occasionally we can experience storms. As with any sort of camping it's then a game of survival, which at times can be enjoyable in its own right. I really enjoy storm camping. In this event I  pitch a very low A frame with my bug bivi set up underneath, the windward edge, whichever that one is will be pitched right to the ground, or with just the hint of lift on the centre tie out, which is achieved using a 30cm guyline.  The main pole height is set as low as 60cm. The bug bivi has a top zip entry which facilitates the low tarp entry, the bivi is dropped to the floor as I climb in, and is pulled up again once I am in. As an an occupant in these conditions I am more than happy to be warm and dry in my sleeping bag. Food prep is going to be difficult, but it is possible. A simple meal which only needs hot water rehydration is ideal. If the weather is really bad I just east meusli made up with dried milk which I always carry. I  then settle for the evening and night with my podcast, music or a book, and hope I do not need to 'go' in the night - torch and a waterproof handy though just in case. In stormy weather I use my waterproof as a pillow so its immediately accessible. Some keep an old wide necked bottle for such an emergency which can be emptied and washed out the following morning.

So there you have it, a typical daily run with an ultralight tarp. Certainly I find it ideal, even more so than a tent when used with an accessory such as a bug bivi with sewn in ground sheet. Later in the season, around October time I swap the bug bivi for a solid walled nest. Some use a Goretex or other lightweight breathable bivi bag.

If I were to not have any sort of  nest or bivi, I would move up to a 2.7 x 2.5 sized tarp as a minimum, even for solo backpacking. Ironically you gain a weight advantage overall with the larger tarp as you  manage without the nest or bivi bag, all that is needed is a groundcloth, which could be something as simple as a survival blanket. You lose out in respect of protection from midges, mosquitoes and ticks in summer though, and you lose out on the the increased warmth provided by the micro climate formed inside a bivi bag or solid walled nest in colder weather. I rarely now use a tarp without such an accessory. Even with a nest however my tarp & nest combo is around half the weight of a tent which provides in reality less space. My nests weigh from between 325g to 495g, 8 to 10 pegs around 80g, guylines 20g, a stuff sac 25g, so this comes to around 700g to 800g for the tarp nest combo. I use a single walking pole and use features such as trees or rocks or objects such as sticks found in the landscape or camp site to effect my home each evening. I can arrange a suitable arrangement with just one pole, a bicycle, a paddle or even my rucksack stood on end if absolutely necessary.

The tarp nest combo fits in well as part of my regular long distance walking kit. My solo tent is no longer taken on the trail for solo backpacking. Contrary to what it seems I do not obsess about weight. In fact I like to be comfortable. To my mind shelter also includes appropriate clothing, good insulation from the ground at night, and a warm sleeping bag.  There is no merit in being cold or wet. As someone once said to me, 'any fool can be uncomfortable'.

I find the tarp nest combo more practical and comfortable than my solo tent. A tarp does need a little 'pitch' practice before use, this just adds to the fun.

Thank you for reading, please do not hesitate to comment or drop me a line.


Many Thanks
Sean

Fabric Choices for Ultralight gear

 Considered use of ultralight fabrics in this Wrath Outdoor sub 600g shelter system which utilises a ripstop silnylon fly and a PU coated nylon tub floor

Ultralight backpacking gear has to work in the real world, it has to have an adequate safety margin, it has to look after the user in unexpected situations. By the same token it has to offer weight savings over main stream alternatives.

The ultralight backpacking shelter designer is looking at combining a design which cuts away redundant or over engineered features to save weight, adjusts panel shape to cut away wasted cloth and so on. Even using the same materials as the mainstream shelter designer the ultralight design will still be lighter. 

The real game changer however is the fabric and other materials used to make the shelter. These fabrics are the best and most fit for purpose fabrics on planet earth at this time. These fabrics can be quite expensive and utilize everything that modern fabric manufacturing can bring to the table. Yes, the design can make a difference, in the end though there are only so many ways to make a tent or shelter. The utilization of cutting edge fabric is what cuts the weight. Think about the steel body shell of a modern car, its strong fairly light and works well as an outer skin for the average vehicle. Then think Carbon Fibre and Kevlar, if well designed the same shapes can be derived but the parts can be stronger AND lighter. 

Ultralight backpacking gear designers and manufacturers are using the fabric equivalents of Kevlar and Carbon Fibre. Most ultralight tent designs come from cottage manufacturers running low overheads, selling their offering online or direct. So even though the fabric costs are perhaps 10 times more expensive than the usual mainstream tent fabrics the final product finishes up similarly priced or even cheaper than a mainstream relatively heavy counterpart. In this sense ultralight gear is a bargain. If a mainstream manufacturer were to build their products from the same fabric they would price themselves out of the market, which is perhaps why ultralight gear remains the preserve of the cottage gear manufacturer. Mainstream gear has to pay the brand owner, the factory, the distributor and the retailer and in fact for a whole marketing infrastructure to bring the product to market. The actual fabric cost was probably less than 10% of its final value. 

The cottage industry is by definition a low key, low overhead operation with a minimal marketing outlay, perhaps even a single website. Custom builds through word of mouth amongst like minded individuals. The value is added into the fabric and design which is passed on to the final user of the product - the customer. 

So which ultralight fabrics are most popularly used by the cottage gear industry. 

There are four  mainstay fabrics in reducing weight order:  PU coated nylon, Silicone impregnated nylon, Silicone impregnated spinnaker fabric and finally Cuben Fibre. There is little to no loss of shear strength as the weight goes down, but the cost increases quite a bit. Cuben fibre costs around 4 times the cost of silnylon. 

Here's the lowdown on each fabric:

PU Coated Ripstop Nylon: 

Very water resistant. Easy to work with, glues will stick to it, and it has at least one face which is not slippy. Its a good choice for making your own gear. The fabric usually has a nylon base fabric which is then coated with a PU coating which then makes one face of the fabric water resistant or waterproof depending upon specification.  The mainstream manufacturers that are looking to offer a lightweight choice would probably choose this fabric as its fit for purpose, fairly light and as mentioned easy to work with. It is relatively inexpensive so a margin can still be achieved in a supply chain scenario.  The main disadvantage is that PU coatings at the lower end of the quality spectrum can be heavy and when subjected to abrasion will begin to peel or rub off rapidly. 

Ripstop Silnylon

Is very difficult to work with, it is super slippy, glue will not stick to it and you cannot put pins through what will become a waterproof membrane, in essence a manufacturers nightmare. On the other hand, there is no coating to rub off, the fabric is totally impregnated with the silicone. Not even mildew can get a foothold. The fabric still has some stretch and both sides of the fabric are waterproof. The strength is around 4 times that of canvas for the equivalent weight and is much more abrasion resistant. Even small pin holes will mend themselves in time. It is more expensive than PU coated nylon, but it is around 25% lighter. 

In many ways this fabric offers the perfect balance of weight and strength for an ultralight product. You can really feel the weight advantage straight away.  It can be used for either a ground sheet or a flysheet. The fabric poses no real compromise for the end user, all of the negatives fall to the cottage manufacturer that has learned how to work with the cloth.

Some mainstream manufacturers have offered what they describe as silnylon.  Quite often it is a hybrid of silicone one side and a thin coating of PU or other coating on the other to make it easier to glue and work with. Always ensure what you are getting really is 'Silnylon' .You can tell straight away by feel. Silnylon is slippy on both sides. PU coatings have a tacky rubbery sort of feel.

Silnylon is flammable. Consider safety if using a silnylon shelter near an open flame. Having run a burn test or two myself I can report that silnylon is not as flammable as some say but do bear this mind.

Silicone impregnated Spinnaker Fabric:

About half the weight of  standard silnylon and just as slippy, at around .98oz or 25g per square metre this is very light, but twice the cost of standard silnylon. Spinn fabric as its known can either have a polyester or nylon base fabric which is then impregnated with the silicone, personally I prefer the nylon. It has the same advantages of the standard ripstop silnylon, is very strong, has a bit of stretch but is not quite as waterproof.as standard silnylon. Still more than fine though for a flysheet, perhaps not so great for a groundsheet as the pressure of knees or elbows over a small area can force water through the membrane.

The main disadvantage is often the colour choice. The fabric is mainly manufactured for sailmakers, who specify bright colours for spinnakers. Natural white or cream is probably the best choice, or pale grey if you don't mind it.

A 3m x 3m  shelter in such a fabric will weigh less than 300g, incredible really and it  is really strong. Look for sewn on ties with bar tack stitching, as grommets will pull out of the thin fabric unless heavily reinforced and hand-stitched as in the clew of  a sail. Personally I love the look of this fabric but if you are planning to stealth camp the color may be a consideration.

Cuben Fibre

Two drawbacks, cost at this time, the fabric cost is four times that of silnylon, and the fabric is very slightly transparent. Oh and did I mention not so abrasion resistant, so that's three drawbacks. On the other hand its the lightest fabric in this list at a quarter the weight of silnylon. It can also be noisy in the wind so pitch technique needs to be practiced. There is less stretch in this fabric so designs that work well in silnylon do not always translate into Cuben Fibre without modification.

I would say that the huge price hike to gain a few grams over say a spinn fabric shelter is hard really to justify, so I am not going to try, but if you have just got to have the lightest this is the way to go. So, would I choose a Cuben Fibre shelter for myself, erm, yes absolutely! :).