Make sure your joist is straight because once you splice it this way it cannot be repositioned.
How to join two floor joists.
Most often floor joists need to be sistered because of two problems either water damage which leads to rot or termite damage that crumbled the joist.
The extra two inches of vertical distance when a floor is framed with 2 x 10 joists rather than 2 x 12s can be quite important for example.
If there was water damage make sure that whatever leaky pipe or condensation issue caused the rot is fixed.
Avoid making the joint in the center 1 3 of the span.
Common sense tells you that large floor joists can carry more load and spacing joists closer together also increases the load bearing capacity of a floor.
The new sister joist is cut to the same length or slightly shorter as the old joist and is inserted into the joist cavity and snugged up against the old joist.
Place two hydraulic floor jacks under the 4 inch by 4 inch post and raise the post until it contacts the floor joists.
These problems must be addressed firsthand prior to implementing any restoration steps.
Sistering or joining joists the term sistering joists is the practice of overlapping two joists by a certain distance across a beam to create an extended joist.
The answer is yes in most cases if you use real plywood to splice the two pieces on both sides and nail appropriately.
Only raise the jacks about 1 8 inch per.
Raise the jacks about 1 8 inch more.