Your Home’s Structure

Most people are aware of the basic structural components of a home, including the foundation, floor and wall framing, and of course, the roof.

A floor joist is a very important structural member that is often overlooked. The floor joist, with the plywood sheathing on top, works as one to carry any weight above. Just think about what the floor joist carries! There are bathtubs full of water, big kitchens with granite counter tops, and living rooms full of furniture. Then add in a house full of people all gathered in the kitchen around the island, which is normally in the middle of the room. It is really extraordinary. Who remembers trying to move the liner of a waterbed with just a bit of water in it? Just think about how much it weighed full.

When homes are designed, they have to look at the span of the floor joist from two supporting points, and this is where we turn to the Ontario Building Code for minimum guidance.

An example might be that we have a span from point A to point B that is 13’- 0”, and we are going to place the joists at 16” on center. We will need to use nothing smaller than a 2×10 joist. This is pretty specific and there are lots of other items to check, but the point is, this is very important.

We recently were on a job and we uncovered some floor joists that had been compromised with cuts, so when we find what we see in the photos below, we find what could possibly be a failure in the floor joist and someone or something could fall through the floor. If your floor joists are cut, the structural integrity of your home is compromised.

Still have questions about floor joists? Don’t hesitate to ask us in the comments!