Sagging Floor Repair Cost – Is There an Inexpensive Repair Option?

Originally posted 4/20/18, revised 10/15/20

Many of the questions that we address in these articles come directly from homeowners like you.  We try to answer honestly and transparently, so that you can make the best decisions for you and your home.  Whenever possible, we try to be specific, because I hate telling someone, “it depends on your situation.”  It doesn’t matter how true this answer is, it sounds evasive.  

Fixing one or two flooring components isn’t usually that expensive (when compared to other foundation repairs).  What turns a sagging floor into a major repair is based on three questions:

1. How much damage has been done to the flooring structure?
2. Are you going to address the cause of the sagging floor? 
3. Will you keep fixing the same problem areas?

Here at Acculevel, we’ve been repairing foundations and waterproofing crawl spaces since our start in 1996.   Family-owned and operated, we have worked on tens of thousands of homes in our service area.  It is our goal to restore each home to health and stability, as well as provide peace of mind to the homeowner. 

In this article, we’re going to discuss what it costs to repair a sagging floor, what caused the floor to sag in the first place, and how to prevent it from happening again in the future. 

This photo was taken by an Acculevel project manager during a routine free estimate.  Excessive moisture has led to molding and rotting floor joists and beams.

What Does it Cost to Repair Sagging Floors?

In the last twelve months, our customers have paid an average of $4900 to repair their sagging floors.  The costs depend a great deal on which sections of the floor are weakened.  If your floor is soft in only one section and you need some floor joists repaired, this is $8-$12 per linear foot. 

If your floor is sloping towards the center of the home, that indicates your main beam is damaged.  That’s a more difficult repair, that requires more labor and much stronger materials.  Replacing a wooden beam with a steel beam costs between $150-$225 per linear foot.

Need a quick reminder about how to calculate linear footage?  Nolan explains:

This photo was taken by an Acculevel team member after repairs were completed.  The damaged sill plate has been replaced, and the floor joists were sistered.

For a more in-depth discussion about the repair types and costs associated with sagging floors, I recommend this article.  It clearly identifies all of the individual components of a wooden flooring structure, where they’re located and how they’re vulnerable.  It also details the symptoms related to the damage made, as well as how those components are repaired and what they cost.

What Causes a Floor to Sag? 

The number one cause of a sagging floor is moisture.  This can be clear and obvious, if you have standing water under your home.  But it can be harder to notice, when it’s predominantly the result of high humidity and muggy summers.  Whatever the case may be, it’s going to be amplified if you have fiberglass insulation installed between your floor joists.  

Fiberglass insulation absorbs and holds moisture.  This means your joists are snuggled up to damp material, allowing the moisture to transfer to the wood.  Softened wood attracts termites, wet surfaces develop mold, and both of these unwelcome guests are bad for your floor and your home.  

There are some less common possible culprits.  If your foundation is cracked and bowing, this will lower the wall, which in turn lowers the flooring on that side.  Similarly, if your foundation is being eroded at one corner or end, it will lower the entire home in that location.  These foundation repairs need prompt attention- especially if you have a bowing or buckling wall.  For more details about foundation repairs, we have a comprehensive guide that is free and easily accessible.  It’s meant to be a resource for homeowners, so feel free to bookmark it, read the section that applies to your situation now, or read the document in its entirety later.

How Do You Prevent a Floor From Sagging?

There are a number of steps you can take that will reduce the odds of your wooden flooring structure becoming damaged.  They are listed in order, beginning with the easiest and least expensive.

1. Make sure your crawl space has a vapor barrier installed.  This is something you can do yourself, if you are willing and able to get into your crawl space.  (No judgements here- millions of people are claustrophobic.)
2. Check your guttering and extend your downspouts, to keep water from draining next to your foundation.  We have an article that explains why this is important, and it includes a DIY tutorial. 
3. Remove fiberglass insulation and replace it with spray foam.
4. If you regularly have water in your crawl space, have it waterproofed.  
5. The ideal solution is full encapsulation.  This is the most expensive option, but it is also the surest way to prevent a sagging or sloping floor. It also provides your family with a clean and dry home with healthy air for breathing. 

What Should You Do, If Your Floor Is Sagging?

Find an experienced contractor and request an estimate.  Like Acculevel, most companies provide estimates free of charge.  Before you sign a contract for any service, we urge you to verify the company is reputable, insured, and accredited by the Better Business Bureau.   

Please use our free guide, Questions You Should Ask a Contractor.   The article explains why we encourage you to ask these questions, provides Acculevel’s answers, and comes with a downloadable blank guide to use with any contractor you interview.  We do not offer this item as a sales tactic; we want every homeowner to be treated fairly.  Like any other industry, there are unethical people acting as legitimate contractors. They will take advantage of an uninformed consumer and we do not want that to happen to you. 

If you live in Indiana or the surrounding states, contact Acculevel and request a free estimate.  One of our experienced project managers will examine your crawl space and foundation, then recommend the best course of action for you, to keep your home strong and healthy for years to come.