Sunday, August 7, 2016

Slipform Stone Masonry - finishing the lift

I posted a bit ago about how we set up the forms and fill them for the slip form walls of the house.  Since we just completed the first lift and took off the first forms, I thought I'd update with a little more detail about how filling the forms goes.

After you have the forms braced and tied together, you have to put a layer of sand along the front of the wall to keep the concrete from flowing all the way to the rock face.  This makes pointing much easier later.



Then you fill the bottom up to the level of the sand with concrete.  This is the mortar bed that the rocks will sit on.  The first line of rocks is next.  Once they're in place, we go back along the wall and put sand in between them and along the face above them so the concrete stays back and doesn't flow over the face of the stones.


With the sand in place, we fill up the form with concrete to the height of the rocks plus the sand on top.  This step takes a lot of concrete!  Thankfully, the kids have gotten really good at mixing concrete.



Then you continue with that pattern - sand, concrete, stone, sand concrete, stone - until the form is full!  The concrete needs to set for 24 hours before you can take the forms off and look at your hard work.  We did that today and this is what it looks like!



We learned a lot from this first lift.  We didn't put sand between all the rocks at first and got too much concrete around the faces.  We also learned a lot about placing wire ties in the wall so that they don't interfere with the rocks.  We had to cut several of our initial wire ties because they were in the way of the stone work.  Bit by bit, we get better.

On the positive side, we discovered that the 4 of us can do about half a lift in a day of work.  That's not too bad!