Does your house have sagging floors? Or perhaps it’s a related problem: Floors that are uneven or sloped, rather than flat and level. These conditions aren’t uncommon. While some people might consider sagging or uneven floors to be part of what makes an older house charming, it’s a problem that should be corrected. Sagging floors can pose a safety hazard, and can be a sign of serious structural problems. Read on to learn what causes sagging floors, and how they can be fixed 


What causes sagging floors?

The structural system for the first floor of a typical house consists of floor joists that extend across the width of the house foundation. At the perimeter of the house, the floor joists rest on a wood mudsill that’s fastened to the top of the foundation walls. Mid-span support for the floor joists is provided by one or more beams that are supported by the foundation walls and by posts located inside the foundation. In a crawl space, pillars can be used instead of posts –made from bricks, concrete blocks, or even stacked stones.

When the floor sags near the center of the house, it’s because the posts or pillars have settled or suffered some sort of damage. Wood posts can deteriorate from rot, while masonry pillars can collapse. Once the beam loses this support near the center of the structure, the floor joists are certain to sag from the weight of flooring, furnishings, and people.  


How to repair sagging floors

Installing new support posts is the most common way to repair sagging floors. The best practice in this case calls for the use of steel support posts that stand on substantial concrete pads, or footings. Steel support posts are known by other names, such as crawl space jacks, lally columns, braces, and pedestals.


To install a steel support post, it’s first necessary to install a concrete pad that will spread the load carried by the post, and provide a solid base that won’t settle or deteriorate. Then the post is cut to rough length so that it can fit beneath the beam it will support. Once in place, the top of the post can be jacked up by means of a threaded assembly. The installer will extend the length of the post to raise the sagged beam back to level. Since the beam supports the floor joists, they will also be elevated, correcting the sagging floor problem. 

The cost of sagging floor repair

 The simple formula for calculating the cost of sagging floor repair is this: The more posts you require, the greater your repair costs will be. Depending on what your contractor discovers when inspecting your foundation, additional repairs may be necessary. For example, damaged joists or beams may need to be replaced, or crawl space waterproofing may be required, if there’s a moisture problem in your crawl space. Contractors who specialize in foundation repairs, including crawl space repairs, will be able to provide you with a free crawl space inspection and a free estimate for all recommended repairs.