Tarp ridgelines should be staked down to prevent tarp sag. For taut pitch, tarp ridgelines should be pulled taut before tightening stakes and cord tensioners. Tighter cord tensioners will reduce tarp sag around the tightener’s stake-out point. If taut pitch is not achieved by tightening tarp cord tensioners, tauten tarp ridgelines by tying tarp loops to tree branches.
Many tarps don’t come with corners reinforced with grommets or cord tensioners, so be sure you order the tarp with the reinforced ridge line and tie outs you need to install them yourself.
Having tarp ridgelines with reinforced tarp loops is important because taut pitch and tarp sag greatly depends upon how taut the tarp ridgelines are drawn.
Tarps come in many shapes and sizes, but they all have at least one ridge line and at least one open end. They can be organized into three general categories: bivy tarps, mids, and modular expedition shelters (MES). MES tarps may be converted to or from a mids by using modular components such as doors and zippers. This makes it easy to convert your tarp from an open weather shelter for day hikes to a windproof enclosed shelter for overnight trips.
To make things even more complicated there also rectangular tarps, hexagonal tarps and tarp tents.
What to look for in a tarp:
- Many tarp manufacturers sell “mids” which are basically tarp tents – integrated bug netting and floor. The benefit of mids is that they can have zero condensation during cold weather because the interior airspace cannot exchange with the exterior one. Mids should be used during fair weather only if you plan on putting a floor inside otherwise you’re going to get wet from outside moisture that collects at the lowest point of any enclosure (e.g., tent or tarp) when the humidity is high. Because there’s no condensation in mids it’s easy to make them modular by adding doors and zippers for more privacy and wind resistance when needed. Modular tarp tents also have the advantage of better airflow and larger interior space compared to bivy tarps and mids with integrated bug netting. Some tarp manufacturers don’t include trap doors or tarp zippers so you’ll have to buy them separately if you want them.
- The common tarp shape has an A-frame ridgeline with the open end being the foot of the tarp where your feet go when you are inside, which makes sense if you are using it as a tarp tent because that’s where all your stuff will be at night. The tarp ridgeline is usually tied out some distance from the tarp edge on one side creating an asymmetric taper towards one side – tarp taper.
- Tarp taper is important if you actually need taut pitch because taut pitch greatly depends upon tarp taper. Note that tarp taper doesn’t change the shape of the tarp – just its pitch. A-frame tarps can be setup to form a flat roof by making both ends of the tarp ridgeline level with each other which is called “flat roof pitch”. This makes it easier to lie out on top of your sleeping pad or roll inside your sleeping bag for warmth. You can also place your backpack under both sides of an A-frame tarp when there’s no significant slope because placing your pack at one end will push down one side causing everything to slide towards the low end. Flat tarp pitch is a great option when you don’t have trees to tie tarp ridgelines out from or when setting up on snow or ice where stakes won’t stick.
- In colder weather adding wind protection is the more important consideration, so it makes sense to add walls and a floor to your tarp shelter interior by converting it into a midsized tarp tent which can then use different kinds of insulation for warmth such as self inflating pads, foam mats, CCF pads, etc. This will automatically reduce condensation because there’s no airspace between inside and outside walls.
Mids are tarp tents that add bug netting and a floor to tarp shelters for better airflow while providing more protection from bugs, wind and rain. Tarps should be made out of silnylon which is the only material that’s strong enough while at the same time being lightweight and waterproof, capable of taut pitches without sagging in moderate winds, and able to last a long time because it doesn’t fade from exposure to UV light.