This ferrocement water tank for the community well water storage will plaster summer 2020, and we have ongoing workdays Tuesdays to progress this. The existing 5000 gallon steel tank is rusted with holes since it’s installation year in 2000. Replacement tanks of steel and plastic run about $1/gallon. Steel tanks are rated at 15 years service, plastic black poly tanks at 25 years. A plastic 10,000 gallon tank would be at a cost of $10,000.
Our ferrocement tank should be good for 100 years, estimated material costs are in the range of $6000 for our 14,000 gallon tank. But there is a lot of labor in tying the mesh. About 2 months/yr x 6 yrs…many hands.
Ferrocement model building code was developed in Thailand 2001 by the international Ferrocement Society http://ferrocement.org. Ferrocement has been used since maybe 100 years in building seafaring boats, buildings, and artworks.
Our next ferrocement tank will be subterranean, 3000 gallons for rainwater roof catch, starting in earnest by 2021. We estimate that our 2000ft square roof can capture 1200 gal./inch of rainfall. In the meantime, plants near gutter outflows are very happy.