Carrier Beam Repair: Restoring the Primary Structural Support Beneath Your Nashville Home's Floors
Ground Up Foundation Repair provides free crawl space inspections throughout Nashville and Middle Tennessee.
On cost: Carrier beam repair cost varies with span length, repair method, and access conditions. Ground Up provides a written estimate after the free crawl space inspection.
Overview
Carrier Beam Repair
The carrier beam, also called the main girder, is the primary horizontal member that supports your floor joists and transfers their load to posts and the foundation. When a carrier beam cracks, sags, or rots, every joist it carries becomes compromised, causing widespread floor movement across an entire section of your home. Ground Up Foundation Repair assesses carrier beam damage, determines whether repair or replacement is appropriate, and restores full load capacity with minimal disruption to the living space above.
Carrier beam repair starts with a structural assessment to measure deflection, inspect for rot or splitting, and evaluate post and bearing conditions. Depending on severity, the repair may involve sistering a new LVL or dimensional lumber alongside the damaged beam, installing supplemental mid-span posts to reduce the effective span, replacing a deteriorated section, or in severe cases replacing the full beam. The floor above is temporarily supported with adjustable columns while the repair is made, then the floor is brought back to level before supports are removed.
Wondering if this is the right fix for what you are seeing? Learn more about the warning signs: Broken or Cracked Floor Joists in the Crawl Space and Mold on Crawl Space Framing . Or browse the full Problem Signs library for framing repair.
Installation Process
How we install carrier beam repair
Structural Assessment
A technician inspects the carrier beam from the crawl space, measuring deflection with a level, probing for soft spots indicating rot, and evaluating the condition of posts, bearing plates, and the foundation pockets where the beam rests.
Temporary Floor Support
Before beam work begins, adjustable steel columns are placed under the floor joists on either side of the affected span to carry the load safely while the carrier beam is repaired or replaced.
Beam Repair or Sistering
For cracked or split beams with sound wood, a new LVL or structural lumber sister is fastened alongside the existing beam using structural screws and bolts at the engineering-specified pattern. For rot-damaged sections, the compromised wood is removed and a scarf-jointed replacement section is installed.
Post and Bearing Inspection
The posts supporting the carrier beam and their footings are inspected for settlement, rot, or inadequate bearing area. Posts that have sunk, rotted, or are undersized are replaced or supplemented at this stage.
Level Correction
If the beam has deflected, the temporary support columns raise it incrementally, typically no more than one-eighth inch per day on older structures, until the floor is within acceptable level tolerances.
Load Transfer and Final Inspection
Once the beam is repaired and level, temporary supports are removed and the full floor load transfers back to the carrier beam. The technician confirms no cracking or movement in the floor above before closing out.
A failing carrier beam affects every joist it carries, it is not a wait-and-see problem. We always address the beam first before sistering the joists above it, because fixing joists over a sagging beam just delays the inevitable. Derek Veselich, Owner, Ground Up Foundation Repair
Why Ground Up
The difference is in the diagnosis
Get several quotes and you'll see a wide range of prices. The gap isn't luck. It's whether the contractor finds the actual cause and stands behind the work.
- In-house certified crews: we never subcontract your repair
- Optional independent third-party engineer review on larger jobs
- Honest three-tier triage: we tell you what can wait, in writing
- Family owned from the same Shelbyville Highway address since 2009
FAQ
Carrier Beam Repair questions
The most common signs are a long, continuous section of bouncy or sagging floor spanning multiple rooms, gaps opening between walls and floors, or doors that suddenly bind along a central hallway. A failing carrier beam affects every joist it supports, so the problem shows up across a wider area than a single bad joist.
Yes, in many cases. If the beam has cracked or split but the wood is otherwise sound, sistering a new LVL or structural member alongside the existing beam restores full load capacity without replacement. Full replacement is required when the beam has deteriorated through most of its depth or length due to rot, insect damage, or fire.
No. Carrier beam repair is performed from the crawl space below. The finished floor, subfloor, and any floor covering above are not disturbed in most cases. This makes repair significantly less disruptive and less expensive than work requiring access from above.
In many cases, yes, partially. We use temporary adjustable columns to raise the beam incrementally during repair, which raises the floor above it. The achievable correction depends on how long the beam has been deflected and whether finish materials above (tile, drywall) can tolerate the movement. We set realistic expectations during the free inspection.
Cost depends on the length and depth of the beam, the repair method (sistering vs. partial vs. full replacement), access conditions in the crawl space, and whether post or footing work is also needed. Ground Up provides a written estimate after the free inspection so you know the full scope before any work begins.
More Solutions
Other solutions we offer
Beam Repair
Structural beams throughout a crawl space home serve distinct load-carrying roles, the sill plate transfers floor loads to the foundation wall, rim joists close off the floor system at the perimeter, and secondary beams support floor joists between the main carrier and the foundation. When any of these members is damaged by rot, insect activity, or physical stress, the floor system above loses support. Ground Up Foundation Repair identifies the affected beam, determines the appropriate repair method, and restores full structural capacity without disrupting the living space above.
Structural Beam Replacement
The main girder beams and support beams in a crawl space are the primary load-bearing members of the floor system. They span between foundation walls and piers, carrying the floor joists that in turn support the subfloor and everything above. When these beams are compromised by moisture-driven rot, pest infestation, or overloading, the consequences extend throughout the floor system above. Structural beam replacement is the appropriate solution when beams have degraded beyond the point where repair or reinforcement is sufficient. Ground Up Foundation Repair provides beam replacement in crawl spaces throughout Middle Tennessee, using properly sized dimensional lumber or engineered lumber products to restore full structural capacity.
Crawl Space Jack Installation
Crawl space support jacks are adjustable steel columns installed on concrete footings beneath the floor framing of a crawl space home. They provide permanent supplemental support for floor joists and carrier beams that have deflected beyond what sistering alone can address, for spans that are too long for the existing framing depth, or for homes where the original post spacing was inadequate. Because they are adjustable after installation, crawl space jacks also allow incremental floor leveling without additional structural work. Ground Up Foundation Repair sizes, spaces, and installs support jacks to match the load conditions of each specific home.
Floor Joist Repair Plates
Floor joist repair plates, also called mending plates, joist plates, or structural connector plates, are heavy-gauge galvanized steel plates fastened across a crack, split, or notched section of a floor joist to restore local bending and shear capacity. They are most effective when damage is localized to a specific point along an otherwise sound joist, rather than distributed along its length. Repair plates are a faster and lower-cost solution than sistering in specific circumstances, and they are frequently used in combination with sistering when a joist has both a discrete crack point and overall reduced stiffness. Ground Up evaluates each joist individually and recommends the repair method, plates, sistering, or full replacement, that matches the actual damage pattern.
Floor Joist Repair
Floor joists are the horizontal structural members that span from beam to beam beneath your subfloor, carrying the weight of everything in your home. When they are damaged by moisture, rot, or pests, they lose load-bearing capacity and the floors above begin to flex, bounce, or sag. Floor joist repair restores the structural capacity of compromised framing through sistering, partial replacement, or full joist replacement, depending on the extent and nature of the damage. Ground Up Foundation Repair specializes in crawl space framing repair across Middle Tennessee, where humid conditions make joist damage an especially common problem.
Floor Leveling Services
Uneven floors are more than a cosmetic problem, they signal that the framing or foundation beneath them has shifted, weakened, or settled unevenly. Ground Up Foundation Repair diagnoses the root cause of sloping, bouncy, or sagging floors and develops a targeted leveling plan. Depending on the cause, floor leveling may involve jacking sagging joists, sistering damaged members, installing or adjusting steel support posts, or addressing the foundation settlement that started the movement. We restore floors to level without disturbing finished flooring wherever possible.
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