How Much Does It Cost to Replace a Main House Support Beam? [2024 Data]

Normal range: $2,000 - $10,000

Expect to spend about $3,250 to replace a main house support beam. If you need drywall removed, or are working with glulam or wood beams, the total cost can jump to as high as $25,000.

How we get this data
Exposed ceiling support beams in home
Photo: Iriana Shiyan / Adobe Stock
Ginny Bartolone
Written by Ginny Bartolone
Contributing Writer
Updated November 17, 2023
Exposed ceiling support beams in home
Photo: Iriana Shiyan / Adobe Stock

The framework of your home is just as crucial to its stability and longevity as your foundation. Replacing a rotted support beam can typically run between $2,000 and $10,000 or an average of $3,250, depending on the material, cause of the damage, and structure of your home. Prices may run much higher for complex replacements.

See the price range for replacing a main house support beam:
How we get this data
Normal range for U.S.
$2,000 - $10,000
  • Average
  • $3,250
  • Low end
  • $1,500
  • high end
  • $25,000
LOWHIGH

Cost to Replace a Main House Support Beam by Square Foot

Support beams are the horizontal rafters that connect to vertical joists and columns. They are found in your home’s roof, ceiling, walls, floor, and garage. There are many factors that contribute to the cost of identifying, removing, and replacing a rotted beam. On the most basic level, start by considering the cost of materials for the beam itself. 

Depending on your home’s structure, age, and unique needs, your contractor may recommend natural wood, manufactured wood, or even steel beams to replace the rotted culprit. The ranges below take the width and variety of the material into account:

Support Beam MaterialAverage Cost Range per Square Foot
Laminated Veneer Lumber (LVL)$3 – $12
Natural Wood$5 – $90
Glulam$6 – $40
Steel I or H Beam$6 – $80

In addition to the cost of the beams, remember to add an average of $1,000 to $5,000 for labor.

5 support beam materials compared visually, including natural wood, glulam, and steel H beam
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Support Beam Replacement Cost Breakdown

The process of replacing a support beam always begins with diagnosing the extent of the problem. Start by calling your local foundation repair pro the moment you detect sagging floors, large cracks in your walls or ceiling, or rot on an exposed beam.

Permits and Inspections

All structurally related projects in your home must begin with an inspection. The cost of a foundation inspection, for example, averages $600. Inspection costs can run higher for more complex projects, such as when investigating a larger horizontal foundation crack.

The cost of building permits varies depending on where the beam lives in your home but can range up to $2,000 if the project is considered new construction. Thankfully, a contractor will research and pull permits for you before getting started.

Structural Engineer Report

Since altering a support beam nearly always requires the sign-off from a structural engineer, budget between $350 and $750 for their expertise as well. The cost of a structural engineer report depends on the complexity of the beam and what it holds up. The inspection of a load-bearing wall, for example, will cost just $100 to $200 per hour, while a roof inspection and report cost up to $600.

Temporary Support Posts

Contractors will typically include the cost of temporary support posts in their flat fee since they will bring the materials along for the job. If you are only installing a support post—also known as a lally column—the process will cost an average of $2,500. These posts support the area with the missing beam before replacement. For example, you will see lally columns around a missing basement support beam to fortify the floors overhead.

Drywall Removal

Unless we're talking about exposed beams in your rustic living room or in the case of a pier and beam foundation, you'll need to remove drywall to expose them. Drywall removal costs between $0.30 and $0.45 per square foot. 

Replacement Beam

As we noted above, the materials of the beam will heavily affect the price tag. The cost of steel I-beams ranges anywhere from $6 to $18 per linear foot. If the project requires something a bit more cost-friendly, the price of an LVL beam ranges from $3 to $12 per linear foot. Glulam beams, another popular engineered material, cost between $6 and $34 per linear foot for materials alone, whereas wood can range anywhere from $5 to $30 per linear foot, depending on the materials.

Labor

Labor prices will depend on the type of specialist required for the job. As we mentioned earlier, a structural engineer will charge an average of $100 to $200 per hour. For larger projects, a general contractor will charge between 10% and 20% of the project's total.

Replacing Drywall and Paint

The cost of replacing drywall when all is said and done adds another $0.50 per square foot. Painting the ceiling to streamline the look with the rest of your room costs an average of $250, but you can get the price down to about $100 if you're up to doing it yourself. 

Factors That Influence the Cost to Replace a Support Beam

Person fixing steel support beam
Photo: Daisy Daisy / Adobe Stock

These unique contributing factors have the most say in the cost to replace a support beam. When you meet with your carpenter or structural engineer, they'll be looking at the following factors to determine your estimate.

Access to the Beam

An exposed beam in the center of your living room is much easier to replace than one in a crawl space. In this case, the contractor will simply add temporary support posts and remove the old beam. Beams inside walls or under flooring and subflooring require more labor, while crawl space and basement supports are the trickiest to access, adding to the time required for the repair.

Additionally, if your contractor needs to work around things like electrical wiring and plumbing, they might call in an electrician or plumber to ensure everything is in working order before closing up the space.

Weight-Bearing Load

Load-bearing walls will likely cost more to repair than non-load-bearing beams that separate two rooms. Contractors may be required to spend more time stabilizing the structure before completing the work, increasing the price for both labor and materials.

Material and Size of the Beam

Your engineer may recommend a specific material and thickness for your new beam. For example, beams bearing a great deal of weight or those susceptible to termites might be best replaced by a manufactured wood or steel beam.

Regional Factors

Lastly, where you live can play a role in the price to replace a rotted support beam. In addition to basic differences in the cost of living around your area, expect varying prices based on:

  • Whether you live in an older home

  • Local permits costs

  • Access to materials

  • Regional weather

How Much Does It Cost to Replace a Beam by Type of Damage?

In the best-case scenario, the rot does not extend beyond a single beam. A trained structural engineer will be able to identify what led to the rot and how much additional work you should expect.

Dry Rot

Despite its name, dry rot is a form of fungi that flourishes in moist and humid areas. The outside of the wood may look dry, hence the name, but contains fungus that breaks down the cellulose of the wood. 

In addition to the $1,500 to $5,000 to replace the damaged beam, expect to pay between $1,000 and $3,500 for extensive fungi removal for the surrounding area.

Termites

The threat of termites can really keep a homeowner up at night. These wood-consuming insects can quickly multiply and threaten the structure of your home in both support beams and the surrounding planks, columns, or floor joists. Termite control costs between $1,300 and $1,780.

Water Damage

From flooding and storms to a burst water mainline, water damage can do a number on natural wood, especially for load-bearing beams. Water damage can cost between $1,200 and $4,600, depending on the extent of the issue. If the damage occurred in your basement or crawl space, you may end up with related foundation repair costs, ranging from $2,200 to $7,800.

Sinking, shifting, and cracked foundations can also lead to problems with structural beams, especially those already experiencing rot. If you experience extreme changes in your foundation—or if the beams were incorrectly installed in the first place—this could lead to overloading the beam itself. An excessive amount of weight on all or one part of the beam may threaten its integrity. Depending on the extent of the issue, add an average of $4,530 to the cost of replacing the foundation beam itself.

How Much Does It Cost to Replace a Rotted Support Beam Yourself?

Replacing a structural element of your home is not advisable, especially for load-bearing support beams. In most areas, and especially in condos or housing developments, you'll likely need to call a licensed and certified contractor to obtain a permit for the work and handle the project.

You can address issues that may impact the structural integrity of your home or escalate project costs by watching for signs of termites, dry rot, or the need for foundation repair. Call a pro to help get these resolved as early on as possible.

Saving Money on the Cost to Replace a Main House Support Beam

While you never want to cut corners when altering the structural elements of your home, there are ways to be smart about the process. Here are some ways to keep costs low when replacing a main house support beam:

  • Investigate the issue early, especially something as severe as sagging floor foundation repairs. Your costs will wrack up the longer the rotten beam affects the structure of the area around it.

  • Speak to at least three general contractors to compare costs and ensure their payment schedule meets your needs.

  • Discuss possible cost-effective material solutions, such as LVL beams.

  • Work with a contractor that can address all surrounding issues at once in one lump sum to cut down on travel and overhead fees.

  • Research local permit fees ahead of time to understand how to fit them into your budget.

Frequently Asked Questions

Call a foundation repair pro to replace a rotted support beam. Your contractor will likely install temporary support to the area while replacing the beam with new wood or steel. Load-bearing elements of your home—such as the horizontal beams that run along your floors, walls, roof, and ceilings—should be inspected by a trained structural engineer. Call these experts the moment you detect rot, water damage, or foundation issues in your home. 

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Learn more about our contributor
Ginny Bartolone
Written by Ginny Bartolone
Contributing Writer
For the past ten years, Ginny Bartolone has encouraged readers to enhance their DIY skills in a wide range of home and lifestyle topics.
For the past ten years, Ginny Bartolone has encouraged readers to enhance their DIY skills in a wide range of home and lifestyle topics.
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