How to Build a House: Installation of the Floor System

The installation of your floor system will depend on the design of your house. The guidelines we will use are 24ft wide x 48ft long with a cantilevered bay window. The floor joist will be 2inch x 10 inch we will space at 16inch centers. The girder and sill plates you learned how to install in part 1.The first thing that we are going to want to do is square up our floor or foundation. This is a repeat process and the reason for this is you will want to constantly check for squareness.

Take your tape measure and measuring corner to corner or from the right corner to the back left corner and from the left front corner to the back right corner. These two measurements should be the same,if not adjust and make them the same so you have a square starting point. Now that you have a square foundation with your seal plate down and the girder in place, We will need a string line. We will want to take the string line and run it from front to back checking for high spots and/or low spots. If you have any high or low spots you will want to shim or notch accordingly. You should not have no more than a 1/8 inch variance.

The next step we will need to follow up with is sorting our lumber in our scenario we will separate all of our 2 inch x 10 inch x 12 foot floor joist. We will check for crowns,twist,bows and warps. The importance of separating your lumber is so you will not install a floor joist that is going to cause you problems especially a bad crown. This will also allow you to get the bad lumber replaced so you are not at a stand still in the middle of framing your floor.