Here's my attempt at a slip form masonry stone wall. I wanted to install a new door to my basement, but before I could I had to fix the CMU wall that had failed. It was built without a footing, with no reinforcement, and without grout filling the blocks. On top of all that it wasn't even built to the depth of the stairs, so soil was passing under the wall and into the stair area.
After doing this one wall I'm not sold on the idea of slip forming a stone wall. I bought the book referenced here and tried to follow the instructions. What I didn't like in the book were that the stones appeared to be set on edge. With the bedding plane perpendicular to the wall. This doesn't usually look like a real stone wall and can lead to spalling as water can get in behind the layers of stone and then freeze/thaw will pop parts of the stone off. So that was one thing I did different. I also didn't "slip" the form up, instead we built enough forms to do the whole wall. We had to do that since it was getting cold (right around the magic 5 degrees C for concrete) and I didn't want to remove the forms before the concrete had time to set. So I didn't get to see how things were going with each layer. If I did maybe I could have changed things a bit. While I don't hate the look, it sort of looks like "stone stuck in concrete". None of my friends will see any difference to a real stone wall, so it's good enough for the stairs to the basement. What I do like about slip formed walls is the ability to form the wall with reinforced concrete.
Click on Pictures to see larger image.
Since I wrote the above I have come across Tomm Stanley's web site and book Stone House - A Guide to Self-Building with Slipforms, which has some great photos and techniques, like using rags to help stop the concrete from running down the front of the stones. His photos also showed that the chipping of the dried concrete is part of the job. When I first removed the forms I thought I had screwed up.
...develop, race, win!