My Cheap Emergency Kayaking Shelter
This project was a chance to construct a cheaper version of a commercial emergency shelter costing over $100. Using common blue tarp material reduces the cost considerably, and doing it yourself makes it even cheaper. The vinyl/polyester tarp material sews up quite nicely. I decided that for a 4 person shelter, two 8 ft x 10 ft tarps would be optimal. I was able to get the tarps on sale at a local discount store (Bldg 19) for $1.89 each, normally about $4 each. Either way, considering that we are dealing with about 6 yards of wide coated material, it would cost about 6 yds x $7.50 /yd = $50 incl s&h using commercial coated nylon. So I got by with $4. You must also have access to a sewing machine. I use commercial Dacron sail thread obtained from a sail loft in the area. A model of the shape is shown below., along with an attempt to hang it within my breezeway to show the size of the prototype shelter. The final shelter rolled up weighed only 2 pounds. On the good days can double as a beach blanket.
Click photos for larger images
The first step is to fold one tarp in half on the long side so that you have a folded 8' x 5' tarp on the floor as seen in Figure 1. Square up the folded tarp because these tarps are not always square. Do not trim the bottom of the tarp, but trim the side and top of the tarp. Make the cut on the inside the of folded reinforcing that has the grommets. Save the selvage that you trim off because you can used it later as reinforced loops. Do the same thing for the second tarp.
Cut off about 2 ft of the top corners as seen in Figure 2. You don't have to be exact here, but I mark the cut with a ruler and magic marker. This will form the peak of the shelter. Also do this for the second tarp. Try to get the side and cut corners all the same length on both tarps.
For each tarp you will sew one ridge seam of the peak as seen in Figure 3. You will need alot of room to handle the tarp material on your sewing table. I used a flat folded seam for strength. Try to get the seam to come out even at the peak so that things will align later.
This next maneuver is even more bulky than the last one. You will sew both of the two sections together as seen in Figure 4. I suggest starting at the bottom on each side and sew up each side. It is just easier to manhandle the tarp starting this way. Again I used a flat folded seam. When you start joining the roof ridges, going up from the corner on each, you may find that because of sloppy tolerances, the peak does not meet perfectly. You may have an offset hole with too much material on one side, which is what happened to me seen below. Ignore that for now.
The vent on this prototype was sewn on the top of the shelter mainly to cover up the offset hole. I chose to make a tunnel vent and sew it onto the hole at the peak. I enlarged the hole to fit the vent. To do this you need a sewing machine that can do sew sleeves as seen in the photos below. It was a sloppy complicated sew because the blue tarp material does not stretch. In retrospect I would not recommend this method. It would be easier to just sew up the offset hole and forget about neatness.
For this prototype I sewed tab loops on the top of the vent to suspend it from a tree or extended paddles. If you skip the tunnel vent, use some of the edge material you trimmed to form loops and sew them to the peak instead of on the top of the tunnel vent as I did. This will give you some place to suspend the shelter. Also seen in the photos are tab loops sewn at each of the four corners of the shelter to suspend the shelter in a tent configuration.
There are no tabs at the bottom (although there could be) since normally for an emergency shelter the users would tuck the excess tarp inside the shelter and sit on it.
Alternate Vent System
I don't recommend the tunnel vent because it it just too fussy to make. But you need some means of ventilation and some means to regulate it. In my next prototype I will place the vents on the sides of the shelter. If you are sheltered on uneven ground, there will be air ventilation under the shelter walls. And anyone sitting inside can just reach down and lift a portion of the wall up for ventilation. One suggestion for a vent system is to put holes on each side of the shelter so the wind could blow in on one side and out the other. You still want to be able to shut the vents and have them close during rain.
This system would have a flap covering two holes. One hole on the top about 2” in diameter, the other large enough to get you fist through. Normally the outside flap will cover the hole against the wind and rain. When you want to open the hole for ventilation, you reach through the bottom hole, grab the flap and push it back in the top smaller hole, leaving the bottom hole open for ventilation. The other four vents would act like outgoing valves to let air out. Or you can open the other ones for increased ventilation. The vents should be placed offset towards the corner of the wall so that wind coming through would not blow directly on the back of a person sitting against that wall.
Rev. March 12, 2007