The best choice depends on access to the joists obstructions in the floor system or current remodeling plans.
Shore up floor joists.
Nailing two 2x4s together will work to span about three joists unless the sag is under a weight bearing wall.
Set a hydraulic jack and post under the beam and jack up the joists about 1 8 in.
Jacking them up too fast may cause cracks in the walls and floors overhead.
Floor joists are usually set either 16 or 24 inches on center.
This type of repair may require a building permit and usually requires extensive.
Joists carry the weight of walls furniture people appliances and anything else placed on the flooring they support.
But 36 inches on center is ok with a subfloor of 1 1 2 inch tongue and groove boards.
A day until they re level.
Sistering the joists is one of the ways to stiffen the floor and will make a big difference.
Please double check the type and size of the joists.
You may need to add some blocking to the floor joists to distribute the load.
Typically the posts are eight foot adjustable devices that can be placed under a sagging beam or floor joist.
You said truss a few times and the two are not the same.
But if couple of joists shore things up why not throw in a couple more.
Usually wooden floor joists are 2 x8 2 x10 or 2 x12 timbers their size depends on their length the amount of load they re designed to carry and the building codes in effect when the house was constructed.
Another way is to build a supporting wall under the room near the center of the span.
Tack a beam under the sagging joists.
For more serious weaknesses you may need to shore up the floor joist structure with a cross beam and lally posts.
You can shore up floor joists and reduce the bounce in a number of ways but the six methods outlined here represent a mix of common and not so common solutions.
You should use a termite shield between the.
If the joist is acceptable as is ensure you use at least 3 5 to 5 inches of lumber on top of the jackpost long enough to catch onto several floor joists in order to spread the stress and.
One technique or a combination may be your most practical solution.
These adjustable posts can be used to shore up a sagging floor or even raise the floor if need be.
If the floor joists are conventional lumber they.
There is no chance adding about 6 or 7 sister joint add too much weight to the center column is there.
