Floor Joust Overlap

This handout is intended to provide only general information for further information contact the building safety division.

Floor joust overlap.

Floor joists or beams provide the below surface support for the wood subfloor of a room. Building code requires the use of blocking for floor joists that exceed 2 inches in width by 12 inches in depth. Drooping and joist sag can be seen in the photo. Since this is a repair of a faulty or damaged floor joist it is imperative to do this project correctly and there are a few big mistakes to avoid.

Blocking is also needed each time the joist overlaps with a center beam and every eight feet between two joists. Not required to provide structural support but often provides a type of supplementary support. Additional support for the floor joists is achieved by nailing the ends of the joists into headers. Sounds like butting them end to end would solve this issue.

When you remove the floor covering you will see more flooring underneath possibly underlayment definitely subfloor. If the floor joists overlap then you will have the center of the 6th joist at 48 inches on one side of the floor and 46 1 2 or 49 1 2 on the other side of the floor. Not sure if that makes sense or if i have this all wrong. Though joists may be any size that you desire using typical floor joist and beam specifications ensures that you can find hardware to fit the joists and that the floor provides adequate support for furniture and other items in a room.

Floor joists lapping splicing 2013 california building code section 2308 8 table 2304 9 1 the following are general requirements for floor joist lapping and splicing based on the 2013 ca building code. Floor covering or finish floor this is the visible floor the one you see and walk on and can be changed out. Section r502 10 of the international residential code states that header joists can be the same size as the floor joists when the header joist span isn t greater than 4 feet but if the header joist span is more than 4 feet you ll need to double the header joist and ensure that it s capable of. The long view makes the overlap seem longer but i believe the nearest one is less than a foot with very few nails.

How does the overlapping joists work with the sub floor.