Every house starts with a foundation. It’s where the structure meets the earth.
Our foundation started with stakes and strings to mark the general position of the house (accurate to a couple inches). Then we chalked over the strings.
The chalk marks showed where to dig our footings. Our footings have been dug and we’ve embarked on the wonderful world of batterboards and stringlines.
A batterboard is a simple structure made of stakes. Its purpose is to provide a stable place to tie a string to so that you can mark the actual dimensions of the foundation.
We have two styles of batter boards:
* short
* tall
The short batter boards are made of 3′ stakes and they’re used on the high ground (where we don’t have a stem wall, the slab just flows down into a footing).
The tall batter boards are made of 4′ stakes (some with a couple additional 3′ stakes to give us the height we need) and they’re used on the low ground (where we have an actual stem wall).
Once the batter boards are setup then you need to start setting, measuring a moving strings. These strings define the actual dimensions of your house so they have to be really accurate.
We started out this process by putting the strings where it made sense, then measuring our distances to try to get the dimensions correct. After moving a few of the strings this way, we realized that this really wasn’t the way to go about the process. You really have to get your corners set at 90 degrees, then start moving both ends of a line to get your dimensions.
So, how do you get your corners to be 90 degrees? Geometry. A 3-4-5 triangle has a 90 degree corner between the 3 and 4 legs. Since our house is a basic 32’x47′ rectangle, we used 30-40-50 triangles. We measured 30′ out on the short side, and put a piece of tape on the string. Then we measured 40′ out on the long side and put another piece of tape on. Then, we measured the diagonal. If it’s longer than 50′, the angle is obtuse; if it’s shorter than 50′, the angle is acute. If it’s exactly 50′, then we have a 90′ angle.
It took us a lot longer than we expected to get our strings set. It’s a surprisingly difficult activity and we had several weather delays.
Once the strings were all set, we were able to move onto the fun part of actually building something…