As an experienced builder, it’s fun to think of ways to improve productivity. Just imagine all the time and money you’ll save. This blog post explores three realistic earthbag building options: 1x = typical earthbag method; 2x = polypropylene tubes instead of bags; 3x = mechanized hyperadobe (raschel mesh tubes) on curved walls. (Note: An earthbag machine with 4x potential will be tested soon in Nepal, but we’ll save that for a later date.)
At the heart of the matter, it’s all about working efficiently as I’ve explained in my Earthbag Building Guide and DVD. Obviously, doing everything the hard way by hand — digging soil and mixing ingredients, carrying materials long distances and working alone with low quality tools will take much longer than the more efficient methods outlined below.
1x = typical earthbag method: This is the normal rate of construction for most earthbaggers working by hand using poly earthbags (rice bags, sand bags, etc.).
2x = polypropylene tubes instead of bags: The normal rate of construction using tubes is about twice as fast as using bags. The building process with tubes is more fluid, like an assembly line. The main savings come from not having to stop and tie tops of bags, pin corners and fill extra gaps between bag ends with plaster. Plus, tubes are often less expensive than bags.
3x = mechanized hyperadobe (raschel mesh tubes) on curved walls: The Quick Wall machine method was profiled on our blog about three weeks ago. Basically, the Quick Wall machine is a tube filling device on wheels that frees up one worker much of the time. This particular building method is well worth emphasizing because it’s so efficient. In fact, it’s the main reason for this blog post. $50 in parts and a few hours of assembly time could easily save days or even weeks of labor. That’s a phenomenal return on investment.
But the cost and time saving benefits don’t stop there. For instance, mesh tubes are less expensive than polypropylene tubes. Barbed wire between courses of mesh tubes can often be eliminated on vertical walls in non-earthquake area. Additional time can be saved by building curved walls such as roundhouses or freeform curves instead of walls with corners. (But plan carefully or the added roof work can cancel out some of the savings.) Further savings are possible by using techniques such as stockpiling suitable fill material such as road base that doesn’t need mixing right where you need it. A tractor for hoisting concrete for the bond beam and other tasks will save even more. For lots of extra information, search our blog for keyword hyperadobe and/or raschel mesh.