Leveling High Points in Wood Floor Framing

Floor Frame Components

• The floor frame consists of a sill plate that attaches flat to the foundation; a rim joist, made by turning joists on their sides and installing them to form a perimeter frame on top of the sill plate; and the floor joists. It’s essential to use rim joists that are straight and strong. Once in place, they are less likely to crown than are the floor joists that span the distance between the sill plates and load-bearing walls.

Checking for Level

• The simplest way to determine if there are high points in the framing is by stringing a chalk line along the length of each joist, positioning it on top of the rim joist on either side. Framing contractors use two workers to do this once the joists are in place. The workers move from one end of the floor to the other, checking each joist for level. If the joist rises above the chalk line, the workers will snap the line to mark the joist. The line is perfectly level, so only the high points of a joist will appear above the line.

Leveling High Points

• A handheld power planer removes the high points of a joist quickly. The framer will use the chalk line as a guide and plane down the joist until it’s level with the line. You can use a manual planer, or a handheld sander, but it will take longer.

Considerations

• Choose joists in person from your local lumberyard, if possible, instead of asking the lumberyard to select and deliver the boards. Don’t buy joists with obvious bows, and examine single joists by turning the joist on end and raising one end to eye level. Look down the edge of the joist to see if is straight before purchasing. If you’re not constructing the floor frame right away, store the joists flat and stacked in a covered building on pallets to reduce warping.