Making a tarp - "Erätoveri"

A few years back I decided to make my first actual tarp, and after some research ended up using the design of Finnish boyscouts' tarp, the Erätoveri. The tarp is square, measured 3x3 meters and has grommets in the corners plus three grommets in between on every side. Also, some grommets are also inserted in the center, but only on the inside. This was meant to help using a tensioned line while pitching, but I've actually never needed them.

For the fabric I used the only decent fabric available locally at that point, and that is "Autex". Autex is nylon with polyrethane coating with aluminized backside, weighting around 80g/m2. Not ripstop, but very waterproof and definitely not breathable. It cost me 5.95 euros per meter, 1.5 meters wide, so I needed 6 meters. This cost me about 36 euros.

First thing to do was to cut the six meter piece of cloth to two pieces, 1.5x3 meters each. Then I sew the pieces together with a flat-felled seam, creating a 3x3 meter square.

Then I measured and marked the locations for the grommets, and cut some reinforcement pieces. I used fabric pieces salvaged from an old broken-down backpack. I used pins and tape to hold the reinforcement pieces in place, and sew them on the fabric.

Next step was to sew the sides. I used only one pass with the sewing machine, with the fabric edge folded twice on itself to prevent fraying. Then I cut small cross-shaped slits into the fabrics and inserted the grommets.

Reinforcement and the grommet.

I did not use any kind of sealant on the middle seam. There is an ongoing debate on this, and it all boils down to the materials that are used. If one uses all-synthetic braid when sewing, the seam is supposedly stronger and lasts longer, but needs to be sealed with a seam sealant or tape. However, if one uses 100% cotton braid like I did, the cotton absorbs some water and swells, sealing the holes in the fabric all by itself. The downside is the supposed decomposing of the cotton thread. However, after three years of use, the seams are still fine, and no fraying is visible. No leaks have been detected either.

The entire costs of the tarp came down to about 45 euros, including the fabric, braid and grommets. The finished tarp weights around 800g.

Pitched with five stakes and a small piece of cord.

Pitched wit five stakes, a walking stick and one cord.

Three stakes and a walking stick, low-tetra design.

Pitching in a -10 C weather in February.

Actual use as a two-person winter shelter. Worked nicely.