Crawl space specialists · Knoxville, TN
Crawl Space Repair in East Tennessee
Fix the framing, the supports and the rot the damp has already cost you.
Crawl Space Repair
How the load gets carried
Before the individual services below, here is the repair in one drawing — what is sagging, what that does to the floor above it, and the support we set underneath.
Taking the load off a sagging girder
- Callout 1. The problem: Years of ground moisture under the crawl space. Damp wood loses strength, and damp ground gives way under whatever is standing on it.
- Callout 2. The damage: The support settles, the girder goes soft and dark, and someone stacks shims under it to buy a few more years.
- Callout 3. The damage: You feel it upstairs first — a floor that slopes, bounces, or has opened a gap at the baseboard.
- Callout 4. The system: Adjustable steel supports on poured footings take the load, brought up gradually to measured elevations. Forcing a floor cracks everything above it.
- Callout 5. The system: Rotted joists get sistered or replaced, and the ground gets sealed and drained so the wood stays dry this time.
Crawl Space Repair
Sagging & Uneven Floors
Floors that bounce, slope or feel soft are usually telling you about the framing below.
The usual cause is not the floor. It is a girder or joist that has lost strength to rot, a support that has settled into soft ground, or a span that was marginal when the house was built and has slowly given up.
We get under it and work out which. Then we correct it to measured elevations, lifting gradually over time where the house needs it rather than jacking it in a single afternoon — moving a floor too fast cracks everything above it.
Nearly always this comes back to moisture. Wood that has been damp for years is wood that has lost strength, which is why we look at where the water is coming from at the same time.
Worth knowing: A floor that has settled over decades does not always come all the way back, and forcing it can do more harm than the sag. We will tell you what is realistic before you commit.
Signs you need this
- A floor that gives underfoot in one particular spot
- Furniture that has started to sit visibly out of level
- Gaps opening between the floor and the baseboard
Crawl Space Repair
Piers & Support Jacks
New support where the original has settled, rotted or was never enough.
Adjustable steel supports are set on proper footings and brought up to take load off a failing girder or an inadequate span. Because they adjust, the floor can be brought back gradually and re-checked over subsequent visits rather than forced.
Where an existing pier has failed, the question is why. A pier that has settled into ground that stays wet will settle again unless the water is dealt with, so we look at both.
Every support goes on a footing sized for the load and the soil. Setting a jack on the dirt is how you get a second call two years later.
Worth knowing: This is crawl space framing support, not foundation underpinning. If your problem is a settling foundation or a structural wall, that is a different trade and we will refer you rather than take it on.
Signs you need this
- A block pier that is cracked, leaning or crumbling
- Shims stacked up on top of a support
- Visible sag along the line of a main girder
Crawl Space Repair
Wood Rot & Joist Repair
Replacing the framing that years of damp have already taken.
Rot needs moisture, and it keeps going as long as the moisture is there. We cut out what has gone, sister or replace joists and girders, and treat the surrounding timber.
The sill plate and band joist are the parts worth checking closely, because they sit closest to the ground and take the damage first, and because they carry the wall above.
Then we deal with the water. Replacing rotted wood in a crawl space that is still wet buys you a few years and no more, and we would rather do it once.
Worth knowing: We cannot always tell how far rot has traveled until we open it up. Where that is a risk, we will say so at the estimate rather than surprising you with a change order.
Signs you need this
- Wood that is soft, dark or crumbles when you press it
- Fungal growth on joists, sill plate or subfloor
- A soft spot in the floor above one particular area
Crawl Space Repair
Mold Treatment
Treating what has grown, then removing the conditions that grew it.
We treat affected surfaces and remove growth from the framing. That part is straightforward.
The part that matters is what comes next. Mold in a crawl space is a humidity problem wearing a costume — treat it without dropping the moisture level and it will be back within a year. So treatment is quoted alongside whatever is keeping the space wet, and we would rather not do one without the other.
Once the space is sealed, dry and held at a sensible humidity, treated wood stays clean.
Worth knowing: We are not a licensed mold remediation contractor and we do not do clearance testing. For a large or health-related mold problem you want a remediation specialist — we handle the crawl space conditions that caused it.
Signs you need this
- Dark or white growth on joists and subfloor
- A musty smell that keeps coming back after cleaning
- Staining that spreads across a season
Crawl Space Repair
Foundation Vents
Closing off the openings that were letting the wet air in.
Crawl space vents were standard for decades on the theory that moving air dries a space out. In a humid southern summer the opposite happens: warm wet air comes in, hits cooler surfaces and leaves its water behind.
Where a crawl space is being sealed, the vents get closed and sealed properly as part of that. Where the space is staying vented, they at least need to work — covers intact, clear of the soil line, and screened.
Which of those is right for your house depends on the space and what else is being done, and it is a decision we make at the estimate rather than by rule.
Worth knowing: Sealing vents is right in a sealed, conditioned crawl space. Closing them off while the ground is still open and wet traps moisture in, so this does not happen on its own.
Signs you need this
- Open vents on a house with a damp crawl space
- Broken, rusted or missing vent covers
- Vents at or below the level of the surrounding soil
Crawl Space Repair
Access Doors
A sealed, insulated way in that is not a gap in the envelope.
The access is a hole in the side of a sealed space, and on a lot of houses it is the weakest point — an untreated panel leaning against the opening, or a door that rotted out years ago.
We fit an insulated, gasketed door that seals against the frame and latches shut, sized to the opening. Where the access is below grade and taking water, we deal with that too rather than fitting a good door into a wet hole.
It is a small item on an estimate and it protects everything else that was done.
Worth knowing: On a below-grade access, the door alone will not stop water coming in — the grading or a well around the opening has to be sorted at the same time.
Signs you need this
- A plywood panel or loose cover over the access
- Daylight or draft around the opening
- Water running in at the access after rain
What it costs
Crawl Space Repair price ranges
Guidance, not a quote. Where your job lands depends on the size of the crawl space and what is actually causing the problem — which is what the free estimate is for.
- Sagging floors — piers & support jacks$1,800 – $8,000
- Wood rot & joist repair$1,500 – $6,000
- Mold treatment$1,200 – $4,500
The rest of the crawl space
Most houses need more than one of these. If you are not sure which, the estimate will tell you — and it is free either way.
Waterproofing
Stop water getting in, and move the water that is already there back out.
Explore waterproofingCrawl Space Encapsulation
Seal the ground off, then keep the air under there dry for good.
Explore crawl space encapsulation
We cover 34 towns across 6 East Tennessee counties — see the full service area.
Get your crawl space repair estimate
A free on-site estimate takes about an hour, and you get a written price before anyone starts. Monday–Friday, 9am–5pm.