Uneven Floors in an Old Huntsville House: Shims, Joists or Piers?
Uneven floors in an old house in Huntsville usually come from one of three things: a crawl space floor system (beams, joists and piers) that has sagged or shifted, a part of the foundation that has settled into the soil below it, or seasonal soil movement between our wet winters and dry Septembers. The fix follows the cause. Shims and new support posts under a crawl space house typically cost $1,000 to $3,500, while settlement that needs underpinning runs $10,000 to $20,000 in national cost guides. So the first job is finding out which problem you actually have.
Why older Huntsville houses end up with uneven floors
Huntsville grew from 16,437 people in 1950 to 72,365 in 1960, and a lot of the city’s older housing dates from that jump. Census figures (ACS 2024 5-year) show 18.8 percent of Huntsville’s homes were built in the 1960s alone, the highest 1960s share of any place in Madison, Limestone or Morgan counties. In ZIP code 35802 (Jones Valley and the Medical District) about a third of homes were built between 1950 and 1969; in west Huntsville’s 35805, around Lowe Mill, it is 42 percent. Downtown ZIP 35801, which takes in Twickenham, Old Town, Five Points and Blossomwood, has a median build year of 1965, and more than a fifth of its homes went up before 1950.
Those houses are now 55 to more than 100 years old. The oldest sit on pier-and-beam, brick, stone or unreinforced block foundations, and the Space Race ranches mix slab and crawl space construction. Slab, crawl space and basement homes are all built here. Across the river, Decatur’s ZIP 35601 (Old Decatur and Albany) has a median build year of 1968, so the same questions come up there. Wood framing, masonry piers and the soil under them have all had decades to move.
Sagging floor or settling foundation? Signs to look for
A few patterns help sort out what is going on before anyone quotes a fix:
- A dip in the middle of a room, worst away from the outside walls, often points to the floor framing under a crawl space house: a beam that has dropped between piers, posts that have sunk or rotted, or joists that were notched for plumbing years ago.
- Doors that stick only in late summer and fall, or cracks that open and close with the seasons, point more toward soil shrinking and swelling.
- Stair-step cracks in exterior brick, a gap between wall and floor, or one corner of the house clearly lower point toward settlement of the foundation itself.
These are clues, not a diagnosis. A contractor’s free evaluation is a sales estimate, not an engineering opinion. If two companies tell you different stories, or the job is large, an engineer’s report from an Alabama professional engineer (PE) typically costs $300 to $1,000. Our foundation inspection and engineer’s report page explains the difference.
How Madison County soil and weather move old floors
Huntsville International Airport averages 54.29 inches of rain a year (NOAA 1991–2020 normals). December is the wettest month at 5.87 inches and September the driest at 3.49 inches. That wet-winter, dry-fall swing is the yearly shrink-swell cycle, and it is why some floors feel worse in October than in March. The drought years people remember are 2007, the driest year on record at 28.65 inches, and 2016, when September brought 0.47 inches and October 0.77.
The soil matters too, but not the way “red clay” marketing suggests. NRCS soil data show the common Tennessee Valley red clay soils such as Decatur are only low-to-moderate in shrink-swell. The thin Barfield soils over limestone, the largest soil series in Madison County at about 13 percent, rate high, and about 17.5 percent of the county’s acreage is in high or very high shrink-swell soils. Our post on Madison County soils goes deeper, and you can look up your own lot on the free NRCS Web Soil Survey.
Ways to level floors in an old house: shims, joists or piers
Shims and support posts. In a crawl space house where the soil under the piers is stable, companies can raise a sagging beam a little at a time, add steel support posts and shim the gap. This is the $1,000 to $3,500 end of the range. The crawl space repair page covers this work.
Joist and beam repair. Where framing has cracked, sagged or been cut, joists can be sistered (a new board fastened alongside) and beams reinforced. It is often paired with shimming, so ask for each item priced separately.
Piers and underpinning. When a footing has settled, steel push piers or helical piers carry that part of the house down to firmer material. National ranges are $1,000 to $3,000 per push pier and $2,000 to $4,000 per helical pier, and a whole-house lift and level runs about $20,000 to $23,000. See house leveling and piers and our push vs helical pier comparison.
All prices are typical national ranges from This Old House (2026), Bob Vila (2024), HomeGuide (2026) and Angi (2026): estimates, not quotes. One honest note: a century-old house rarely goes back to perfectly flat, and forcing it can crack plaster and trim. Ask each company how far they plan to raise the floor and over what time.
Permits and licenses before work starts
In the City of Huntsville a permit is required when labor and materials exceed $250 or any structural work is involved (Inspection Department FAQ); the contractor pulls it and must hold a City of Huntsville business license. The City of Madison’s residential permit application has “Repairs” and “Foundation Only” permit types. Unincorporated Madison County requires permits for work of $1,000 or more, per the county’s published summary. Athens and Decatur: permits vary by city; your contractor confirms with the building department. If piers are involved, ask whether the City will want an engineer’s letter.
Alabama requires a Home Builders Licensure Board (HBLB) residential home builder license for any repair to a home when the cost exceeds $10,000 (Ala. Code §34-14A-2(16)), and the HBLB says work that affects structural integrity needs the unlimited license, not the limited one. Jobs under $10,000 need no HBLB license. Ask for the company’s HBLB license number and check it on the HBLB lookup before signing. Our permit guide has the details.
Uneven floors in old houses: common questions
Is a sloping floor in an old house always a foundation problem?
No. In a crawl space house the slope often comes from the floor framing: a beam that has dipped between piers, posts that have sunk, or joists that were cut years ago. Seasonal soil movement and settled footings are the other common causes. A walk-through under the house usually narrows it down, and an engineer can confirm it if quotes disagree.
How much does it cost to level floors in an old house?
National cost guides put leveling with shims and support posts at about $1,000 to $3,500, and leveling that needs underpinning at about $10,000 to $20,000. A whole-house lift and level runs about $20,000 to $23,000. These are typical national ranges, not quotes; written, itemized quotes from local companies are the only real number.
Do I need a permit to level my floors in Huntsville?
In the City of Huntsville a permit is required when labor and materials exceed $250 or any structural work is involved, and the contractor pulls it. Unincorporated Madison County requires permits for work of $1,000 or more, per the county’s published summary. In Athens and Decatur, permits vary by city; your contractor confirms with the building department.
Get written quotes for your floors
The fastest way to learn whether your floors need shims, framing repair or piers is to have a couple of companies look under the house and put their findings in writing. We connect Huntsville-area homeowners with independent local foundation repair, crawl space and waterproofing companies for free, no-obligation quotes. Request your free quote or call (256) 999-1367. Working on an older home in Decatur? See our Decatur foundation repair page.