How to fix sagging floors: An explanation of causes and repairs

By the time you notice a sagging floor—whether it’s on the first or second story—it’s likely developed into a major structural and safety problem.

According to building codes, the threshold for how much sag is permittable is low. Very low. For a floor that’s 16-feet wide, any sag greater than 4/5 inches could indicate structural damage.

There are several things that might be causing your sagging floor on the first or second story, but they all boil down to three main causes: water damage, a settling foundation or improper joist placement:

• Water damage
  Excess moisture in your home’s crawl spaces can lead to dry rot, weakening of the wood or mold growth. Over time, water will weaken the structural integrity of your floor joists—the support beams holding up your floor—causing them to sag. The sagging floor repair cost will depend on the extent of the damage and the accessibility of your crawl space.
• Foundation settlement
  Weak soils can allow your foundation to settle or sink. All homes settle to some extent, but if it leads to sagging floors, extensive foundation cracks or sticking doors, your home likely has sustained structural damage.For more foundation problem signs, click here.
• Improper joist placement
  There are many different sizes of floor joists. Which ones your contractor chooses will largely depend on the width of the floor in question, the expected load the floor will carry, as well as local building codes. If a contractor chooses the wrong width—or places them at incorrect intervals—the joists will not sufficiently carry the load of the floor, causing a sagging floor. The experts at Helitech Waterproofing & Foundation Repair will analyze your home’s structural damage and determine how to fix your sagging floors in the most cost-effective and non-invasive manner.

How to fix sagging floors: An explanation of two common methods

Each home is different, and therefore no sagging floor repair method is one-size-fits-all. The sagging floor repair costs will largely depend on the extent of the damage and the intricacy of the repair.

Here are two primary methods we use to fix your sagging floor on the second or first story:

1. ”Sistering” the sagging floor joists in the basement—or on the second story
   Sistering is a process by which we carve out the rotted segment of a floor joist, treat the wood to prevent future rot, and attach a ”sister” beam next to the rotted one. This way, the load intended for the rotten beam is put on the new beam, and the structural integrity of your flooring system is restored. Sistering is easiest to perform where the joists are not severely damaged and there is easy access to the crawl space in the basement. If there is not easy access to your floor joists, such as with sagging floors on the second story, the ceiling might have tobe ripped out during the process, which can drive up repair costs.
2. Jacking up floor joists in the crawl space
   If the sagging floor joists—whether in the basement or second story—are severely damaged, it is likely you will have to use a floor jack. Basically, floor jacks are just adjustable steel beams which can be used to support your flooring system temporarily during the repair or replacement. Often, if your floor joists are almost—or completely—rotted or damaged, any repairs will require jacking up floor joists in the crawl space while we remove the affected boards and replace them. Once the replacement is finished, we will remove the jacks, and the new joists will support your floor.

At Helitech, we are invested in choosing the most efficient and cost-effective way to repair your flooring joists. That’s why we offer a free consultation where we’ll evaluate the damage and give you an estimate for the necessary work.