Earthbag Tipi Photo Gallery, Page 3

Most earthbag building websites use wooden arch forms. They are very bulky. We designed a much simpler arch form using PVC pipe.

The gray PVC is rigid conduit. This was too rigid for new rice hulls in 14" x 26" sandbags. Next time, we would use regular PVC pipe for this. We also tried these forms with earth in the bags. The rigid PVC conduit worked great.

The 1/2" PVC arch form is cut in half. The arch form parts in the picture are slightly bent because they were used once. The cable ties on them keep the collar centered over the joint.

The collar is 1" PVC, cut in half lengthwise, then put back together and secured with hose clamps.

The form brace is made out of PVC filled with rebar. We could have used bent rebar, but bending rebar is not that easy to do. The PVC also slides out from between the bags very easily when done, but rebar would catch on the bags.

Form braces are placed in between the courses. The dollar bill and the gallon water bottle are shown for size comparison.

Form braces are placed in between the courses.

The bags are stacked along the arch forms. For the actual building, barbed wire would have been used between the courses, and the courses would have been tied together, as shown on Kelly Hart's tutorial. This would have made the arch even stronger. However, we were doing a test. If we could make our test arch support itself without using any barbed wire or ties, we knew that our building would work with them included.

The arch is completed before the form is removed.

Another row of bags is laid across the arch, to keep it in place.