Question
Mark,
I need to build a small retaining wall on the lower side of my house.  It'll be about two feet high at the edge of the house, making a 90-degree turn (curved, not sharp) and going along my driveway.  The total length will be about 23 feet, and at the other end it's only going to be about a foot high.  I am going to put some topsoil behind it, and some sod on top...so it does need to be fairly sturdy.  I would LIKE to build it out of poured concrete, then later on put some faux-stone on it so it'll look a little better.  
My biggest problem is figuring out how to build a mold to include that curved 90-degree turn.  I thought maybe I could use some quarter-inch plywood, and I wanted to know if you thought that would work.  Also, any suggestions or recommendations you might have (even on other forms of construction) would be very welcome.
Warm regards,
David Gardner

Answer
Hello,

Materials you can use include plywood,masonite,bender board (redwood and plastic) and other forms of composite, bendable concrete form material (some claim to have superior bending properties).

If you use plywood,stay with 1/4 inch. This size will be much easier to bend. Wetting the plywood will aid in bending. Construct a frame to mount the plywood or other material to. This could be perhaps pieces made of thicker 1/2 inch strips of plywood or bender board. Bender board comes in 2 x 4 size strips and in lesser sizes. Use spacer sticks to keep the form a uniform width and tie the two sides together with heavy wire or threaded rod. Mount support braces to the sides and to the ends. A frame and bracing is necessary so that no bulges form in the sides of the wall.  Good luck. Let me know if I can be of further help.

Mark Harshman



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