How To Reinforce Notched Floor Joists

As a remodeling contractor and carpenter one common structural framing issue i see alot of in bathroom remodeling jobs are floor joists that were cut drilled notched or need to be cut out to accommodate plumbing pipes and drains.

How to reinforce notched floor joists.

After several centuries of service floor joists in older homes may sag or crack. 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. I have a notch in the bottom of 4 2x8 joists in my basement to accomadate the tub drain and water lines. Someone made the 2nd floor living space so they added new 10 deep joists the badly notched ones in the photo.

Notches will compromise the strength of the new joists but some notches are acceptable depending on their location. Structural floor joist repairs. Improper notching can weaken a floor joist. Eleven years later i find the toilet flooring and subfloor all failing because of the sag in the floor created by sawing through an i beam joist that runs the length of the house tackitybits says in a post at fine homebuilding s breaktime forum.

Then set new joists same height as existing ones alongside the old. Tack a beam under the sagging joists. Long spans of joists in newer homes may wobble or bounce from foot traffic. Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.

Sometimes joists are notched at the end where they bear on a wall or sill. The reason there is only access from one side is due to the fact that there is another joist 8 deep from when this was originally an attic rafter. How to make floor joists stronger. The joist was cut to make room for the pvc waste pipe for the toilet.

The notch was made where the floor joist recessed into a wood beam supported by chimney corbeling. The notchs are 1 1 2 high by 5 lengthwise i might need to notch them a little higher seeing as im replacing a faulty part of the drain and the new piece is going to interfere with the drywall going back up.