Cutting A Floor Joist Out Of The Floor Above

A nominal 2 8 board measures 1 1 2 by 7 1 2 inches cutting the new joist.

Cutting a floor joist out of the floor above.

The notching and boring rules of thumb for solid lumber are shown in fig. One of our recent whole house balloon frame remodeling projects had a floor so out of level that anyone sitting on the toilet in the future bathroom risked sliding off. Such is the case with this house after a small electrical fire. Second floor joists are nailed to the bearing walls and supported by a piece of stock called a ribbon board in this case 1 6 stock let into the studs see drawing right.

Each type of floor joist offers its own unique benefits and drawbacks which is why those working in carpentry all tend to have their own favorite floor joist option though they are still required to be well versed in each type of floor framing. But sometimes you have to cut out an old floor joist and put in a new one. When installing a new joist on a foundation wall you may need to notch the bottom edge so it. Cut into floor along the lines between the joists but several inches inside your marks for the centerlines of the joists.

I was careful not to cut too deep where i suspected the floor joists were and came back and finished cutting over the top of them with the reciprocating saw laid down as much as possible. The space between the beam and the floor boards above was 7 inches so i decided to use regular framing lumber and rip a 1 2 inch off the width of a 2 8 framing member. The only problem was the subfloor was nailed to the floor joist with some very large nails and they did not come out very easily. The three main types of floor joists used in home construction are solid lumber i joists and open web floor trusses.

Codes don t directly address how many holes and notches you can cut in a joist.