Residents shouldn’t simply accept sagging floors as part of everyday life; their causes could be serious and expensive.

Inspection can assist homeowners in determining the optimal way to repair sagging floors. Each repair method will vary in terms of materials and costs involved, with damage caused to support columns being one possible cause of the sagging floors.

Things to look for, when fixing a sagging floor


Floor joists provide essential support for both subfloors and upper floors in any house, providing support from subfloor to upper floor levels. If floor joists become damaged due to shifting soil or flooding damage or termite infestation, their performance could become severely diminished over time causing flooring sagging or dropping altogether. If they deteriorate further they could even lead to unevenness of floors sagging or distorting as a result.

Sagging floors are one of the first telltale signs that something may be amiss with your home’s structure, while doors that won’t stay closed or close properly, cracks in walls or ceilings, and windows that rattle and clink when someone passes are other indicators that something is amiss in your house.

Older houses may feature sagging floors due to joists being spaced further apart than current building codes recommend; this issue can also occur in properties with an uneven foundation.

Water damage can cause joists to rot and weaken, especially near plumbing lines. A rotting joist may shift and cause its floor above to collapse causing it to sag even further.

Termite infestation can also damage wood materials like joists and flooring boards, rendering them unfit to support your floor and thus weakening it. By replacing affected boards and joists with new ones, your floor’s strength will be restored and its structure improved.

All sagging floor repairs involve some form of lifting of the flooring structure. Whether this involves replacing sill plates, sistering (reinforcing) joists or raising beams under your floor, the result will be that it rises back up towards its original position – potentially correcting any sagging or dips while making your house feel more solid and secure.

joist to fix the sagging floor

Shoring up floors isn’t for the inexperienced or fainthearted; any project involving raising up an entire house can be dangerous and time consuming. To reduce risks and avoid cracking drywall, plaster, windows and other structural elements it is wise to raise problem areas gradually over several days or weeks using professional contractors as guidance; once repairs are complete a self-leveling underlayment can help finish off this job and protect from future issues.


Your floor is an integral component of its foundation, so when its foundation sags it can put your entire home at risk from moisture issues or structural repairs that will be more expensive in the future. Address sagging floors immediately to avoid costly structural repairs in the future.

Sagging floor foundations can often be caused by excessively heavy loads that exceed their ability to support them, such as large pieces of furniture or structural additions such as fireplaces. Older homes may have sagging floors due to outdated building codes which set structures incorrectly proportioned resulting in their weakening over time.

One common cause of sagging floor foundations is the introduction of pipes and wires through floor joists. Homeowners may drill holes into these joists in order to run plumbing or install HVAC systems; however, these holes may not always be necessary. A power drill should be used only as necessary in order to penetrate minimally into these joists in order to avoid weakening them over time.

Dependent upon the cause of your sagging floor foundations, repairing or replacing the joists may be necessary in order to rectify it. This process can be time consuming and expensive and should only be performed by professionals. Sagging foundations could also be caused by tree roots creeping their way under your foundation.

Installation of new support beams and joists can be the solution to sagging floor foundations, though this requires replacing footings as part of a major project that will involve raising up an entire home and replacing its footings gradually to prevent cracking drywall, plaster or windows during this process.

floor foundation to fix the sagging floor

Sagging floors can be an early indicator of an underlying foundation issue in your home, potentially leading to wall or ceiling cracks, sticking windows and doors and even diminishing value and curb appeal. By taking steps to address sagging floor foundations you can rest easy knowing your home will remain stable and safe in years to come.


Sagging floors can be more than an eyesore; they’re often telltale signs of serious structural issues that require immediate professional intervention. Left unattended, this problem could worsen and result in cracked walls, door jambs that won’t close, windows that won’t close and even irreparable damage to the home’s foundation.

An uneven, sagging floor can cause wood floors to buckle underfoot, while tile and stone surfaces may fracture. If this problem is due to improper construction, however, wood blocking could help stop joists from moving apart; solid lumber should be cut into rectangular blocks to fit each joist perpendicularly before being attached with nails on both sides using nails for additional support.

Sistering can help strengthen sills or joist ends that have become weak over time by fastening identical pieces of wood together, fastened with fasteners to weak joists. Homeowners can complete this task themselves; however, for your own safety it may be prudent to seek professional advice first before beginning this task themselves. Alternatively, jacking the floor might be better, which involves replacing damaged sills and joists with stronger versions set on concrete footings.

Older crawl space homes may also experience soil shifting that contributes to sagging floors. Clay soils expand when wetted then shrink when dry, exerting pressure on foundation and piers supporting the home and exerting more strain than areas closer to perimeter walls.

A team of qualified professionals can typically restore structural integrity to your home by conducting a detailed crawl space inspection, identifying specific issues, and suggesting repair solutions. If weak or uneven crawl space joists are the source of your issues, Crawl Space Jacks may be installed to support them and ensure your home rests firmly upon a solid foundation.

Windows and Doors

Homeowners might not realize the effects of sagging floors on windows and doors until they no longer fit properly – which could be an indicator that there’s something amiss beneath the floor surface. If gaps form around door frames or opening/closing them becomes difficult or gapped windows appear on frames, professional inspection should be scheduled immediately.

Causes for sagging floors include surface problems, subfloor issues or floor joist issues. Surface issues tend to be easiest and least costly to rectify while subfloor and joist issues typically require more construction work, materials and expertise for resolution. A flooring contractor is best qualified to recommend solutions tailored specifically for each home based on flooring material type as well as any structural or environmental influences which might alter repair procedures.

DIY solutions may offer some temporary fixes to address a sagging floor, but this often masks its source. A contractor will typically need access to a crawl space in order to properly identify and address its cause; most homeowners do not possess these skills or experience. Furthermore, venturing into such spaces can be hazardous, making professional assistance your best bet for best results.

window and door of house with sagging floor

Sagging floors can be caused by termite damage, improper floor joist spacing and foundation shifts – which must all be identified and resolved promptly in order to prevent future episodes of floor sagging.

Deflection caused by rotting joists is usually enough to necessitate replacement, and using suitable flooring material and placing the new joist correctly are the keys to long-term floor stability.

Sagging floors can be more than just an aesthetic problem and may pose serious repercussions if left untreated, including potential injury and property loss. Reach out to an Angi flooring expert for more information about diagnosing and fixing this problem in your home.