Hi Steve, I have just purchased your e-book and am very pleased with it. I will several questions over the next few weeks as I finalize my plans for a small outdoor waterfall. First question -- My total project will be about 6' X 4' X 3' tall. I am very handy with wood construction and am wondering if I could build the forms with OSB board, screw lots of deck screws in the wood and then wrap machinist wire around the screw heads. This would be in place of the styrofoam and steel wire. I could make many random patterns with sections of OSB board and various pieces of wood such as 2X4's.
One reason for doing this is so I can have access inside and under my waterfall.
Well, the major concern with using wood is that it will rot over time which is unacceptable. If you have the ability to remove the wood from the inside (quite a job) then I can't see a problem with that.
A word of caution is to make sure the forms are strong enough. People are constantly underestimating the weight of wet concrete so I would use a 3/8 thickness wood at the absolute minimum and still you should expect significant sagging. Still, you could make it work but I would advise that it is not ideal.
The more important factor here is that the ebook building practices deal mostly with non structural building in which the concrete is supported internally by the styrofoam since you do not remove it after construction. If you want to build hollow rocks that are self supporting and SAFE then you will need some real experience with structural steel forming and bending. Your concrete mix needs to be consistent and reliably strong, your steel grid with 10mm rebar must be bent and tied to a 3-d skeleton of 8" on center squares. YOu need to add stucco lathe as a backing spaced one inch off of the structural skeleton and then wrap with chickenwire to help the concrete climb vertical surfaces.
The idea of using styrofoam for a form is it allows almost anyone to build a safe strucure that is self supporting. Structural building requires a good deal of expertise, skill and knowledge.
I hope this information is helpful and thank you for your positive review of the new ebook! Your comments are appreciated.