Adjusting a tarp when the weather turns

Wind pushes on every surface it reaches. A tarp pitched high and flat offers it a lot of surface, much like an open umbrella that flips inside out in a gust. If you lower the ridgeline and set the sides steeper, the surface becomes smaller and the wind tends to slide over it. At the same time, rain runs off a steep surface faster.

Many tarp fabrics, especially nylon, stretch when they get wet and cold. A tarp that was taut in the evening can sag in the rain at night and start to flap or collect water. Polyester fabrics usually stretch less. Adjustable hitches and tensioners make up for this stretch without you having to pitch everything again.

Extra lines at the middle of the sides hold the fabric where it would otherwise flap most. Flapping is not only noisy; it also strains seams and grommets with every movement.

Good preparation makes adjusting in the dark easy. Before sleeping, check the clouds, wind direction and forecast. Attach lines to the middle tie-outs already in the evening, have a few more stakes ready than you need and put your headlamp where you can find it blindly. Use tensioning hitches that you can release and tighten with cold fingers.

Choose a basic pitch that is easy to adapt in the first place. An A-frame or a lean-to on a ridgeline is easy to lower and close. You can even convert a lean-to into an A-frame by pulling the high side over the line and staking it out on the other side.

The order for adjusting: first lower the ridgeline or shorten the poles. Then stake the weather side down to the ground or fold one end in. After that, add extra lines and re-tension all hitches. In persistent rain, check now and then whether water is collecting or lines are slackening.

In thunderstorms or storms in exposed terrain – on ridges, summits, open ground – retreating to a safer place matters more than any adjustment. A tarp does not protect against lightning, and poles or lines do not make it safer. A separate entry describes how to behave in thunderstorms.

In forest during a storm there is a danger of trees falling or branches breaking off. Already when pitching, look for dead branches and unhealthy trees above you; in strong wind a spot under tall trees is generally risky.

Adjusting at night in the rain costs warmth. Put on your rain jacket before going out and work quickly so that sleeping bag and sleep clothes stay dry. Anyone who cannot warm up afterwards, shivers heavily or is confused needs dry clothing, shelter and if necessary help via the local emergency number (112 in the EU).

Practise the adjustments in daylight and good weather before you need them at night. Pitch a tarp as a high lean-to and turn it step by step into a low, closed roof. Time how long it takes and note which lines you need first.

Then repeat it at dusk with a headlamp and with gloves on. That way you notice which hitches are hard to release and where lines are missing. A night with light rain forecast close to home is a good opportunity to try the whole thing in real conditions.

Adaptability is considered one of the main advantages of tarps over tents. Many forms can be built from the same sheet – open and airy in fine weather, low and closed in wind and rain. You do not have to strike camp, only re-rig.

The price is that you sometimes have to get up at night, and a low pitch is more cramped. Many tarp users therefore get into the habit of pitching a little lower in the evening than the weather currently requires. Then there is less to do when the weather turns.