Cut Floor Joist High Spot

To remove the existing floor use a circular saw.

Cut floor joist high spot.

The most basic method is to take a piece of tar paper fold it in half and then push that. Step 2 look at the joist. This will create a weak spot. Bending however is a more realistic concern because it takes much less load to exceed the allowable deflection of a floor.

If the cut outs are too large or in the wrong location the joist can be weakened and unable to support the load it was designed for. To address this unique area of the floor we decided to remove the existing 5 8 inch osb plane the joist using a standard handheld planer and install. What we found is that one technique is to pull up the subfloor and shave down the top of the joist. I noticed the high joist when i removed the old carpet.

Fixing a low joist is pretty straight forward. Sometimes joists are notched at the end where they bear on a wall or sill. We considered it but we just weren t going to do that. Shear is what would cause the joist to break in half and the floor to collapse an unlikely outcome unless the joist is extremely overspanned overloaded or heavily modified.

Start by cutting out a small 1 2 in 2 5 5 1 cm section of the floor joist with a reciprocating saw. A high joist is a different conundrum. Use a circular saw to remove the subfloor to expose the high joist. I cut out a span of plywood over 3 joists total the high one in the center planed it down with my electric planer and was able to reset the same subfloor i cut out.

High areas in the floor are called heaves and low areas are called dips. Then use pry bars and your reciprocating saw to pry and cut the floor joist away from the subfloor. Pry the floor joist from the subfloor with the back of your hammer. The joist on the other side of the crowned joist was properly level meaning it was in plane with the end joist.

A floor joist will bow upward creating a heaved area on the floor above. The joist underneath the hump may appear thicker than the joist on either side of it because of moisture. I pulled all the nails first then cut the path the nails were on with a saw set to depth of the subfloor. Minor high spots for hardwood and laminate floor installations are easily fixed with tar paper shims.

Jack it up and sister join another joist to the original one. Cut only the area where the hump is not the entire floor. Back to addressing the high spot.