I use ordinary uncoated rebar when I layout walls (and flat work) because it is fast and effective. There is margin for error doing it this way but there is with any method of layout. I’ll keep this as concise as possible and as always if anyone has any questions, please feel free to ask them.
In the past, I used metal fence posts in addition to rebar but only in really wet soil because the wide metal stakes provided a stable anchor. But they are kind of a pain to fix string to them so rebar is all I use now. I don’t like the coated kind because it prevents the line from gripping. The first step is to set them at the desired batter or the tilt of the wall, so use a level and a tape to help out with this. First pound the rebar in the ground a few inches or enough to make them stable. Next, mark the rebar at an interval coinciding with your batter ratio. Since mine is 1″ per foot (1:12) and my final height will be around 4’… I made a mark at 3′ to reference my batter. This means that when I hold my level plumb, I want to be 3″ away from the rebar at the 3′ mark. You can easily move the rebar around without bending them if you didn’t drive them in the ground too deep. Once I get what I’m looking for, the stakes are pounded in deep and double checked that my desired batter is still there.
Here you see four stakes set to 1″ per foot batter.
Next, tie a string on the bottom of the rebar… this is your base string and can stay as a reference until you are done. The next string can be set at a comfortable working height anywhere you want. I like to have room in between the strings and because the batter is the same on all my stakes it doesn’t really matter were they are set. Here is why….
When you eye through the strings, you want to see one line. The base string is the datum line or fixed point to use for reference. ( Note: If you zoomed the picture you will see that strings are not perfectly in line. This is because this was the best I could do looking through the screen on my camera!) Hopefully you get the idea though….I’m trying to see one string.
If your stakes are twisted or have a different batter than each other, they will not line up and will look like this…..
See how the string on the top of the picture lines up but as you look along it to the bottom it separates? That would indicate that the rebar closest to me is tilting in OR the opposite stake is tilting out. Make your adjustments according to your desired batter using your tape and level. Most of the time you need only a gentle pull or push to get them straight. If you loosen the rebar, tap it down a little more..sometimes I’ll tamp the ground around the stake with a hammer too. With the strings in line with each other, you have created a plane to which you can set the snouts (farther point on a stones face) to your line which will make a super flat wall. If you want more texture, let the snout break the plane of the lines now and again. If you do the latter technique you will need to add a new line above the top string to have a clear reference. It doesn’t matter that it is higher than the original top line…remember, both rebar stakes are set to the same batter and the string will line up.
I don’t want to have a super flat surface so the snouts on my wall break the plane here and there.
This will illustrate how it looks…
Now the top view, same side. The angle makes the stone look like they are set behind the line….they aren’t.
This is what it looks like when you blend both techniques of building to the line and breaking the plane. This is a view from back to front.
Front to back. EDIT: J posted a good question about using clips to fix the strings. In my reply I mention a clinch wrap with the string. If you click on the pictures above and below you can get a close up of what I’m talking about. Thanks J.
It took me about 20 minutes from start to finish to layout the oven base and I have staked out whole projects in a few hours. I wish the oven base would go as smooth! Mud Oven Update coming up