August 28, 2014 | 2034 views
About these sagging floors
Q. Before my grandfather left us, he gave my wife and I the house we now live in, so we never had an engineer’s report to find things like structural problems. Our floors are sagging on both the first and second floors, and we’re wondering if this can be corrected without too much expense. We know it may cost thousands, but is there a ballpark way to know?
It’s hard to give ballpark numbers for what you’ll need to do sight-unseen, because the individual activities needed to accomplish the task will vary. In general, the lifting and leveling of an old structure that’s used to being a certain shape will probably only be partially successful, but you can get better results than the sags you described for between $5,000 and $10,000. I start with the highest load affecting the floor structure and follow that load path, accumulating loads mathematically until I’ve added all contributing factors down to the lowest floor. This is what nature does, and nobody ever gets away with defying nature. Nature always wins.
Unfortunately, the foundation or column footings — made of concrete, I hope — may be overburdened, and “punching” downward into soft ground. Some people call this normal settling, but since the Romans, Egyptians and Babylonians all knew and did something about it, I refer to this as just careless ignorance. Ignoring the location of the most impacted load is just unforgivable, according to Mother Nature, who does not forgive.
The structure works just like a ladder, so each level has some relieving to do in order to correct. Temporary walls are constructed on either side of bearing walls or the beams above. Each temporary support wall, made of wall studs and bottom and top plates, must be constructed one above the other. Otherwise the sag just transfers to another area. With properly calculated beams and properly located columns in place, the job is to install the new structure in the correct places.