How much does it cost to repair a sagging floor?
Ashburn, VA

How much does it cost to repair a sagging floor?

Ashburn, VA

How much does it cost to repair a sagging floor?

$300 – $2,000 average cost to repair surface issues
$2,000 – $7,000 average subfloor replacement cost
$4,500 – $20,000+ average structural reinforcement cost

Get free estimates for your project or view our cost guide below:

$300 – $2,000 average cost to repair surface issues

$2,000 – $7,000 average subfloor replacement cost

$4,500 – $20,000+ average structural reinforcement cost


Get free estimates for your project or view our cost guide below:
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Tamatha Hazen
Written by
Tamatha Hazen
Edited by
Kristen Cramer
Fact-checked by
Tara Farmer

Sagging floor repair cost

Sagging floor repair costs $300 to $2,000 to fix surface-level issues like minor unevenness due to wear and tear. The cost to replace a subfloor is $2,000 to $7,000 for repairing water damage, rot, or inadequate support issues. Major structural repairs cost $4,500 to $20,000+ to fix joists or foundational supports.

Average sagging floor repair cost
Repair type Average repair cost
Surface-issue repairs $300 – $2,000
Subfloor replacement $2,000 – $7,000
Structural reinforcements $4,500 – $20,000+

Surface issue repair

Sagging floors caused by surface issues are the least severe and least expensive to repair, costing $300 to $2,000 on average. These can include minor unevenness or slight sagging due to wear and tear over time.

Repairs may involve adding shims, using a leveling compound, or replacing small sections of flooring. The process is relatively straightforward and can often be completed in a day or two, depending on the extent of the problem.

Subfloor replacement

A damaged subfloor can contribute to the floor sagging by failing to provide adequate support to the flooring above. Replacing a subfloor costs $2.20 to $4.75 per square foot installed or $2,000 to $7,000 on average to replace the subfloor for the entire home or basement. Replacing the subfloor is often necessary when it has been compromised by water damage, rot, or extensive wear and tear.

Structural reinforcement

Structural reinforcements are the most severe and costly repairs at $5,000 to $20,000+ on average. These are necessary when there is significant structural damage or inadequate support for the entire floor system. Repairs may involve sistering joists (adding new joists alongside existing ones), replacing damaged joists, installing additional support beams, or repairing the foundation.

Get free estimates from floor repair companies near you.

Cost to repair a sagging floor by method

Sagging floors may be caused by weakened joists, subfloor damage, foundation problems, water or termite damage, or uneven concrete slabs. Repair costs vary significantly based on the underlying cause and extent of the damage, the repair method chosen, and the scope of work required.

Sagging floor repair cost by solution
Repair solution Average cost
Reinforcing (sistering) floor joists $150 – $325 per joist
Replacing damaged joists $350 – $1,000 per joist
Replacing subfloor $2,000 – $7,000
(entire home or basement)
Foundation repair $4,500 – $20,000
Water damage repair $1,200 – $5,000 per room
Termite damage repair $225 – $2,500
(for termite treatment only)
Concrete leveling $5,000 – $25,000
(entire home or basement)

Reinforcing floor joists

Reinforcing the floor joists for sagging floors involves adding support to existing joists by sistering floor joists together. Sistering costs $150 to $325 per joist and involves bolting a new joist to the rotted, weakened, or undersized one. This process strengthens the floor structure, helps prevent further sagging, and improves overall stability.

Replacing damaged joists

When joists are undersized or damaged due to rot, insects, or structural issues, they often need to be completely removed and replaced with new ones to repair a sagging floor. Joist replacement costs $350 to $1,000 per joist. Costs can reach $5,000 to $10,000 to replace all the joists in the room or $10,000 to $30,000 to replace the joists for the entire level of the home.

Floor joists supporting a home's first floor, shown from the basement
Floor joists supporting a home's first floor, shown from the basement

Foundation repair

When sagging floors are caused by foundation settlement or movement, you may need a foundation repair that costs $4,500 to $20,000, depending on the house size, foundation depth, and repair method. Addressing foundation issues may involve methods such as mudjacking, underpinning, or installing piers to stabilize and level the foundation.

Water damage repair

Water damage repairs for sagging floors are a complex and potentially expensive process costing between $1,200 and $5,000 per room. The restoration typically involves water removal and drying, followed by flooring replacement as needed.

Beyond these primary steps, water damage repair may require additional measures that significantly impact the total cost and complexity of the restoration project. Costs may include:

Termite damage repair

Termite damage can lead to sagging floors, creating a serious structural issue that compromises a home's integrity and safety. As termites consume wooden support structures, floors may become uneven, soft, or visibly sunken. This damage often goes unnoticed until it's extensive, making early detection and treatment crucial.

Termite damage repair includes treating the termite infestation, removing damaged wood, and replacing it with new, treated lumber. It often requires collaboration between pest control professionals and carpenters to ensure the structural integrity is restored.

  • Termite control costs $225 to $2,500 to treat with chemical or bait station methods. Severe infestations requiring whole-home termite tenting cost $2,000 to $8,000.

  • Carpenters charge $30 to $100 per hour for a standard carpenter, or up to $200 per hour for an expert carpenter.

  • Floor replacement costs $4 to $15 per square foot on average, with hardwood floors costing up to $25 per square foot.

Contractor installing laminate flooring on underlayment
Contractor installing laminate flooring on underlayment

Concrete leveling

Concrete slab floors can sag over time due to factors like soil erosion or moisture problems. The most effective leveling method is typically polyurethane foam injection, which costs $5 to $25 per square foot. This fast, minimally invasive, and long-lasting repair involves drilling small holes in the slab and injecting expanding foam to fill voids and lift the concrete.

Alternative methods like mudjacking cost around $3 to $6 per square foot. This involves injecting a concrete-soil mixture under the foundation. However, this is more of a temporary fix that is best for slabs, driveways, or patios that don’t support as much weight.

Sagging floor repair cost by material

Some floor repairs—especially those involving crawl spaces or basements—can be done from below without disturbing the flooring above. However, in many cases, accessing the subfloor or structural elements requires removing the existing flooring.

Different flooring materials have varying repair and replacement costs, which can impact the overall project cost. Carpet and vinyl are relatively inexpensive materials that are easier to remove and replace, while hardwood and natural stone floors may incur higher costs. The following table details the average removal and replacement costs for various flooring materials.

Flooring repair cost by material
Floor material Average cost
(per square foot)
Hardwood removal cost $1.50 – $3.50
Carpet removal cost $0.70 – $1.60
Tile removal cost $2 – $7
Carpet $2 – $8
Vinyl $2 – $10
Laminate $4 – $14
Concrete $5 – $8
Cork $5 – $15
Bamboo $7 – $17
Engineered Wood $7– $20
Tile repair cost $10 – $50
Hardwood floor repair cost $11 – $25

Sagging floor repair cost factors

Sagging and other types of floor repairs cost $200 to $1,200 for minor repairs and $500 to $6,000 or more for major repairs, depending on the cause and extent of the damage.

Several factors can influence the overall repair cost:

  • Underlying issue: The underlying source of the problem significantly impacts the repair cost. Foundation problems or water damage are more complex and costly to fix than joist reinforcement or termite damage repairs in most cases.

  • Extent of damage: More severe or widespread damage is more expensive to repair.

  • Floor material: The type of flooring (hardwood, carpet, tile, etc.) can impact costs, especially if it needs to be removed and replaced.

  • Accessibility: Labor costs may increase if the repair is in a hard-to-reach area.

  • Home age: Older homes may have additional complications or require more extensive repairs.

  • Location: Labor and material costs vary by region.

  • Structural complexity: Homes with complex layouts or multiple stories may be more difficult and costly to work on.

Get free estimates from floor repair companies near you.
Repair man checking the floor with a level
Repair man checking the floor with a level

Sagging floor repair FAQs

What causes a sagging floor?

Sagging floors typically result from foundation issues, water damage, or structural problems. Support beams or joists can weaken due to moisture, insect infestation, or age. Poor initial construction, inadequate materials, or improper support spacing may also contribute. Changes in soil conditions around the foundation can cause shifts, leading to uneven floors over time.

What are the signs of a sagging floor?

The most obvious sign of a sagging floor is a noticeable slope or slant in the floor compared to the surrounding areas. Other common signs include:

  • Gaps between the baseboards and the floor

  • A bouncy or springy feeling when you walk on it

  • Sticking doors or windows

  • Cracks in the drywall, especially near the corners or along floor lines

  • Furniture that rocks or feels unlevel

  • Cracked tiles or grout

Who can repair a sagging floor?

A general contractor can often repair a sagging floor, but a structural engineer may be required for severe sagging to ensure the home is properly secured. A foundation repair specialist may be necessary if the foundation is the cause of the sagging. A skilled carpenter may handle repairs involving joists, subflooring, and leveling the floor itself.

Are sagging floors covered by insurance?

In most cases, sagging floors aren’t directly covered by homeowners insurance because they are usually caused by gradual deterioration from normal wear and tear. However, if the sagging is a direct result of a burst pipe, major water leak, earthquake, or sinkhole that damages the floor joists, it may be covered.

Getting estimates from floor repair companies

To ensure you receive precise quotes from a floor repair company or subfloor repair contractor, remember to:

  • Get comprehensive, itemized estimates from at least 3-floor repair companies to compare options.

  • Provide a detailed explanation of the scope of the floor damage.

  • Take photos or videos of the affected areas to share with the repair service.

  • Disclose any prior attempts to fix the issue.

  • Ask about the possible repair methods and their costs.

  • Confirm how long it will take to fix the floor and how long the repair will last.

  • Make sure the repair service offers a guarantee or warranty on the work.

Questions to ask a floor repair contractor

Ask these questions to help you assess the contractor's qualifications, understand the repair process, and ensure you're getting a quality floor repair:

  • Are you licensed and insured in this area?

  • How many years of experience do you have repairing floors?

  • Can you share some references from past customers?

  • Have you tackled repairs similar to the damage I have on my floor?

  • Can you provide a detailed breakdown of the repair costs, including any subfloor work that might be needed?

  • What's your estimated timeframe for completing the repairs?

  • Do you offer a warranty on your repair services?

  • How will you minimize dust and protect the surrounding areas during the repairs? Will you handle all the clean-up afterward?

  • Will your own employees perform the work, or will you use subcontractors?

  • Can you walk me through the repair process and explain the materials you'll be using?

  • How will you ensure the repaired area blends in seamlessly with the rest of the floor?