How to Build a Floor for a New House

Here are the steps for building a floor on a new foundation. The sill plate attaches to the cement and holds the house to the foundation. Everything else is attached to the sill plate.

Difficulty: Moderate

Instructions

Things You'll Need:

• 2x10 lumber
• nails
• hammer
• tape measure
• marking pencil

1. 
    
   sill plate

   The sill plate will fit over the anchor bolts sticking out of the concrete foundation. Sill plates need to be pressure treated or pesticide treated lumber. Most sill plates are either 2x6 lumber or 2x8 lumber. These will be secured all the way around the top of the foundation. Tighten down all the nuts evenly so the sill plate is stable.

2. 
    
   rim joist

   Next, we'll put the rim joist onto the sill plate. We can make rim joists by standing 2x10 lumber on its side and toe nailing the lumber to the sill plate.

3. 
    
   my house rim joist

   The rim joist might not be as stable as we would like it, but once we attach the floor joists, we'll nail the rim joist to them for added stability.

4. 
    
   floor joist attached to rim joist

   Next we'll start to put on the floor joists. These can be 2x10 lumber or TJI composite floor joists. Most floors joists are 16-inches apart for a stronger floor.

5. 
    
   floor girder

   Because of span limitations, most local codes require a girder up the middle of the floor.

6. 
    

   This is usually 2x10 lumber on top of girder piers or even deck blocks.

7. 
    

   Be sure to nail the floor secure by nailing through the outside of the rim joist into each floor joist with at least two nails.

8. 
    

   It's a good idea to use joist hangers for extra stability.

9. 
    

   Once the joists are all in place we can put on the plywood. It's best to use a tongue-in-groove plywood so there aren't any seams.

10. 
     

    The plywood can be secured with nails, but screws are better because they help reduce squeeky floors.

Resources

• http://www.make-my-own-house.com/floors