Framing Floor Joist on a Foundation

Building a house can seem like a daunting task to most people but it does not take a rocket scientist to be able to build one. To build your own house you need some basic knowledge, common since, lots of patience, tools and the right building materials. It may not hurt to have a how to guide to give you guidance or a professional that you can ask lots of questions. The first step in any building project is the foundation. Once you have the foundation it is time to start the floor. The floor is very important because it will hold up the rest of the house so it must be sturdy in order to withstand the pressure applied on it by the walls and roof.

The first step when building a floor is to use a pressure treated 2×6 for the sill plate that will be bolted to the concrete foundation. This is what holds the floor to the foundation and keeps it from being blown over in a massive storm. This sill plate must be pressure treated lumber so it will not rot or succumb to pest because it directly touches the foundation of the house.

Afterwards, you will use 2×10’s for your floor joist which are attatched together with 16 penny nails. The floor joists are placed at intervals of 16 inches on center typically but they can be placed at 12 inches on center if the floor needs to be extra stout. In the past it was customary to place the joist 24 inches on center but it made the floor very weak which is why it is not acceptable with today’s standards. For a floor plan that is longer than 14 feet you may need to calculate the load bearing. This will determine if you need a larger sized joist or a supporting beam in the middle to carry the load.

When you lay out the floor joist you will have one on each end that is called a rim joist which is used to tie them all together. The rim joist is what sits on the sill plate flush with the outside of the house leaving a ledge for the floor joist to sit on the sill plate. This gives you a surface to toe nail the floor joist into the sill plate which ties them together and adds additional strength to the floor.