Last updated 2026-08-21
TL;DR
Slab lift means raising a sunken concrete slab by injecting expanding polyurethane or a cement slurry under it. Start by confirming your state's license class, forming an entity, getting a free EIN and real insurance, then practicing injection control before paid jobs. Thresholds and classes are state specific. Confirm every fee and title with the board that issues the card. There is no national slab lift license.
What is slab lift?
Slab lift is the trade of raising a settled concrete slab by pumping material underneath it until the panel comes back toward level. Crews use expanding polyurethane or a cement slurry. You drill, inject, watch movement, then patch the holes.
The slab is not the product. Control is. You are fighting voids, washed-out base, soft clay, and sometimes a broken panel that will hinge instead of rise. If the slab is already in pieces, lift becomes a judgment call, not a party trick.
Homeowners call when a driveway lip catches a shovel, a sidewalk trips someone, or a garage floor pulls away from the stem wall. The same method shows up under warehouse floors and some pavement patches. Highway work has its own specs. Do not pretend a driveway kit is a DOT procedure.
Two material families dominate. Polyurethane is a two-component plastic that expands and hardens fast. Mudjacking (also called slabjacking) uses a sand-cement slurry pumped with little or no expansion. Both raise a panel. They fail in different ways. Foam can follow a void sideways. Slurry can add a lot of weight on weak soil.
I treat slab lift as a repair, not a soil rewrite. If water is still cutting the base, the slab drops again. Fix the drainage or you bought a warranty claim.
You will hear polyjacking, foam jacking, and concrete lifting. Same job family. The chemistry and the hole pattern change. The liability does not.
How do you start slab lift?
You start slab lift by locking the legal path in your state first, then getting injection practice, then taking paid work. Buy gear last if you can rent. A truck wrap is not a start plan.
There is no federal slab lift license. OSHA still applies the day you drill concrete or open a drum of isocyanate [1][2]. Your contractor card, if any, comes from a state board or a city hall. In California the Contractors State License Board publishes classification descriptions, and none of them are titled slab lift, so you ask which class fits the work you will sell [14]. In Alabama, the general contractor statute keys off a dollar threshold of fifty thousand dollars for the undertakings it covers [9]. Those two facts already tell you the paper is local.
Form an entity your CPA will actually file. Get an EIN. The IRS issues an EIN at no cost through its online application [10]. Open a business bank account. Call an insurance broker who writes contractors, not a friend who writes auto only. Then read the SDS for the foam system you plan to shoot and set Hazard Communication before the first test shot [2].
Practice on a scrap panel. Learn to stop a lift. Overlift cracks more slabs than underfill. I would not take a garage floor as job one.
For state-by-state starting notes, read the how to start slab lift in Alabama walkthrough or the how to start slab lift in California version, and treat every fee as something to confirm with the board.
What actually happens on a slab lift job?
On a standard driveway job you mark joints and cracks, check drainage, drill a grid of holes, inject until the slab moves, then patch. You leave when the panel is in tolerance and water will not sit in a new low spot.
Walk the job before you quote. Look at the low corner, the high side, the downspouts, and whether the slab is one pour or a quilt of patches. Tap it. A hollow sound is a void. A dull sound can be tight soil. Neither sound is a lab test.
Set a reference. A rotary laser or a tight string line beats eyeballing. Shoot elevations and write them down. If you cannot say how far it dropped, you cannot say you lifted it.
Drill. Foam systems often use smaller ports than slurry. Hole size is a system choice, not a national code. Blow out the dust. Silica rules still apply when you drill concrete [1].
Inject in short shots. Watch adjacent panels. Watch door clearance. Stop. Recheck elevations. Patch with a mortar that will stay in the hole you actually drilled.
Write what you did. Photos before and after, hole count, material lot numbers, and the drainage problem you told the owner about. That file is your defense when the clay moves next spring.
Is slab lift the same as mudjacking?
Mudjacking is one kind of slab lift. Polyurethane injection is the other common kind. People use slab lift for both. If a bid only says lift, ask which material.
I prefer foam on interior slabs and on soils that cannot take extra dead load. I still use slurry when the owner wants mass, the access is easy, and the price has to land lower. Nobody has a clean national price index for this work. Local labor and material freight move the number more than any blog chart.
| Approach | Carrier | Hole class (field, not code) | Traffic return | Weight added |
|---|---|---|---|---|
| Polyurethane injection | Expanding two-part foam | Smaller ports, often under 1 in | Often same day | Low |
| Mudjacking / slurry | Cement-sand mix | Larger ports, often 1 in plus | Mix dependent, often hours | Higher |
Those hole sizes are shop practice, not ASTM mandates. Your pump maker's sheet wins.
Foam chemistry sits in the same isocyanate family that NIOSH warned about in industrial foam work. NIOSH wrote, "Diisocyanates are widely used in the manufacture of flexible and rigid foams, fibers, coatings such as paints and varnishes, and elastomers." [4] Treat the A and B drums like chemicals, not magic.
Slurry work is messy and heavy. You need a mixer, a pump that can push grit, and a plan for leftover mud. Do not wash it into a storm drain.
What licenses do you need to start a slab lift business?
You need whatever contractor license your state or city requires for the dollar amount and the trade you sell, plus the usual business registrations. There is no slab-lift-only national card.
California's licensing chapter "does not apply to any work or operation on one undertaking or project by one or more contracts, the aggregate contract price which for labor, materials, and all other items, is less than five hundred dollars ($500)," with conditions written in Business and Professions Code section 7048 [7]. Contracting without a required license is its own offense under section 7028 [8]. That $500 line is not a business plan. Confirm the current text and any local add-ons with CSLB before you price a driveway.
Florida law is blunt on the other end. Section 489.113 says a person who is not certified or registered shall not engage in the business of contracting in that state [15]. Read the whole chapter. Exemptions exist. They are narrower than social media claims.
Alabama defines a general contractor, for that chapter, around undertakings of fifty thousand dollars or more [9]. Plenty of slab lift tickets sit under that line. Cities and other boards can still touch you. Confirm with the Alabama Licensing Board for General Contractors and the city where the slab sits. See slab lift license in Alabama and slab lift license in California for the paper sequence, then verify every number on the board site.
Arizona and Colorado are not copies of either model. Arizona uses the Registrar of Contractors. Colorado leaves a lot of contractor licensing to cities and counties. Start with how to start slab lift in Arizona or how to start slab lift in Colorado, then call the jurisdiction at the permit counter, not a forum.
If you have employees, add workers' compensation where your state requires it, plus unemployment accounts. I am not your lawyer. Read the statute. Then ask the board.
What equipment do you need for slab lift?
You need a way to drill, a way to pump, a way to measure lift, and PPE that matches the SDS. That is the whole list. Everything else is comfort or marketing.
For polyurethane, the core machine is a two-component proportioner with heated hoses on many systems, plus transfer pumps and a generator that can hold the load. For slurry, you need a mixer and a grout pump that will survive sand. I would rent the first proportioner if a reputable dealer will let you. Buying a tired used rig before you have three months of work is how people fund the next guy's bargain.
Winter changes the machine more than the brochure does. Cold A and B sides do not meter the way the data sheet assumes. If you work below the temperature on the sheet, you need drum heaters and a plan, or you stay home. I have seen more bad lifts from cold material than from cheap bits.
Generators get sized off the proportioner plus heaters, not off a guess. Ask the dealer for running watts. Then add margin. A tripped breaker mid-lift is how you freeze a hose.
Rotary hammers, bits, ports, levels, a laser, air or a shop vac, cones, and a mortar kit matter more than a vinyl wrap. A notebook is not optional.
Do not skip chemical PPE. OSHA's construction PPE rule puts the duty on the employer to require appropriate gear [13]. Gloves that melt are not a look. Trailers and service bodies come after you know your hole count per day.
How much does it cost to start slab lift?
Startup cost is mostly the pump, the first drums, insurance, and the months you underbid while you learn. I will not invent a national kit price. Used proportioners and new entry systems sit in a wide band that moves with heaters, output, and whether the hoses are trash. Ask two dealers. Get it in writing.
The cheap line items still matter. Entity filing is a state fee you confirm with the secretary of state. An EIN costs nothing from the IRS [10]. License application fees are board-specific. Never trust a blog for the current amount. Open the fee page on the board site the week you apply.
Insurance is the sleeper. General liability for concrete lifting is not the same as a handyman policy. Some carriers hate residential foam. Budget time for declined applications.
Training packets from chemical vendors can be worth a trip. A framed private school certificate is not a license. Spend on injection practice and on a lawyer who has read your state's contractor act.
Skip the lead-gen subscriptions in month one. Your first ten jobs should come from people who can see your work, not from a portal that owns the customer.
What safety rules apply to polyurethane slab lift?
The two real hazards are silica dust from drilling and isocyanate exposure from foam. Treat both as rule-driven, not vibe-driven.
OSHA sets the respirable crystalline silica PEL for construction at 50 micrograms per cubic meter as an 8-hour TWA [1]. The same standard has an action level of 25 micrograms per cubic meter [1]. Handheld drills have specified control methods in Table 1 of that rule. Read the table. Then follow it.
Foam systems use diisocyanates. NIOSH documented asthma and other outcomes in diisocyanate work and published Alert 96-111 for that reason [4]. NIOSH's pocket guide entry for 4,4'-methylenediphenyl diisocyanate is the quick number sheet many hygienists still pull [12]. Slab lift is not attic foam, but the chemistry family is the same one on those pages. Use the SDS. Run Hazard Communication. Keep unprotected people out of the plume.
OSHA's concrete construction rules also bar putting construction loads on concrete unless a qualified person says the structure can take them [3]. Do not park the heaviest truck on the panel you are about to lift.
Eye protection, gloves rated for the chemical, and whatever respirator the SDS and your hygienist call for are not optional theater. If you have staff, train them and write it down.
How do you bid slab lift work without guessing?
You bid slab lift by measuring the settled area, estimating the void with honesty, pricing material with waste, and adding the time to control the lift. A per-square-foot number without a site visit is how you fund someone else's redo.
I price a mobilization, then material, then labor hours, then the patch. I do not give a firm foam pound count from a phone photo. Clay soils lie.
If you want a simple worksheet so the math is the same on every driveway, SlabLiftPath sells a $149 one-time Mix + Bid-per-Sqft Kit at /start. Use it or a spreadsheet you built. Either beats a number you said because you were tired.
Watch access. A backyard slab through a gate is not a driveway. Watch thickness. A 3.5 inch walk is not a 6 inch garage. Watch joints. A panel that is already broken may need sawing or replacement, and you should say that before you drill.
Put exclusions in the bid. Drainage work, root removal, and level-to-new-construction talk are not implied. Write the elevation target in inches.
Sales tax, permit fees, and HOA rules are local. Confirm them. Do not copy a bid template from another state and hope.
What paperwork do you need in year one?
Year-one paper is an entity, an EIN, a bank account, insurance certificates, a license if required, written contracts, change orders, and job photos. That stack matters more than a logo.
Keep SDS books and a written Hazard Communication program if you have employees or you share a shop [2]. Keep silica compliance notes if you drill [1]. Keep mix lot numbers.
Contracts should name the panels, the method, the target, and what you will not fix. A one-paragraph text message is how collections die.
Sales tax permits, city business licenses, and fictitious name filings are the boring ones people skip. Skip them and you get to explain it to a clerk who has heard every story.
If you work in California, renewal and classification questions belong on CSLB paper, not on a Facebook thread. Same idea in Colorado with whatever city issued the card. See slab lift license in Colorado, then open the live board page.
I keep a simple job folder: bid, photos, elevations, material lots, signed completion. If a slab moves next year, you will want that folder.
Where do soils and water cause the slab to drop?
Slabs drop because the support under them moved. Water is usually the thief. Expansive clay, poorly compacted fill, broken irrigation, and tree roots do the rest.
USGS describes land subsidence as "a gradual settling or sudden sinking of the Earth's surface owing to subsurface movement of earth materials." [11] Most of that national story is groundwater and deep processes. Your driveway is usually shallower. Washout under a joint. Clay that swelled and then dried.
Colorado State University Extension's fact sheet on basement and foundation problems walks through how wetting and drying of soil move structures in that climate [6]. Read it even if you do not work in Colorado. The mechanics travel.
I walk every job for downspouts that dump at the slab edge, beds that flood against the garage, and slopes that send roof water under the walk. If I cannot name the water path, I do not sell a long promise.
A lift without a drainage fix is a pause. Say that out loud. Some owners still want the pause. Put it in the contract.
Soil maps help you guess. They are not a boring log. If the slab is part of a foundation system that is rotating, stop and bring a structural engineer. Slab lift is not underpinning.
What should you skip in the first year?
Skip nationwide certification mills that are not your licensing board. Skip buying two chemical systems in month one. Skip interior house slabs as your first paying job. Skip lifetime warranties.
I would also skip wrapping the truck before you have repeatable patches. People remember a sloppy gray circle in a driveway longer than they remember your font.
Do not start in a license-heavy state by testing the $500 myth on a $4,800 driveway. Read the statute. California's small-project text is real and narrow [7]. Florida's contracting bar is real [15].
Do not dump leftover slurry in a gutter. Do not open drums in a closed garage with the homeowner watching from a folding chair.
Bonding, if your board wants it, is a board number. Confirm it. Do not buy a huge bond because a coach said every real company carries one.
I would not hire a salesperson in year one. You cannot train them on a method you still overshoot.
If a panel is structurally tied to a foundation that is rotating, skip the hero lift. Refer it. You will sleep.
How do you confirm facts with the state board?
You confirm facts with the board by opening the live statute or fee page, then calling or emailing the licensing staff with your actual scope written in one paragraph. Screenshots of a 2019 blog are not confirmation.
Ask three things. What classification covers polyurethane injection under existing slabs. Whether a dollar exemption applies to your bid range. What the current application fee and bond are this week. Then ask them to point to the page.
No article can promise approval time. Boards change packets. Cities add cards on top of state cards. Read the current form.
SlabLiftPath is an independent publisher. It is not a law firm and not a service company. Use how to start slab lift in Arkansas as a map, then verify. If you want the bid worksheet after that, the kit is at /start.
Frequently asked questions
What is slab lift?
Slab lift is raising a sunken concrete slab by injecting material under it until the panel moves back toward level. Most crews use expanding polyurethane foam or a cement slurry (mudjacking). You drill ports, inject in controlled shots, check elevations, then patch. It repairs support under an existing slab. It does not rewrite the soil or replace a rotating foundation.
How do you start slab lift?
Confirm the license class and any dollar trigger with your state or city board, form an entity, get a free IRS EIN, and buy contractor insurance that actually names this work. Rent or borrow a proportioner if you can and practice stopping a lift on scrap concrete. Take paid driveways only after you can control movement. Confirm every current fee on the board site.
Do I need a contractor license for driveway lifting?
Often yes, and sometimes a city card sits on top of a state card. California's small-project text is narrow and dollar-capped. Florida generally bars unlicensed contracting. Alabama's general contractor chapter uses a $50,000 undertaking line, which does not silence cities. There is no national slab lift card. Ask the board that would fine you, in writing, with your real scope.
Is polyurethane slab lift the same as spray foam insulation?
No. You are injecting a structural lift foam under concrete, not insulating a wall cavity. The chemical family still includes diisocyanates, which is why NIOSH pages on isocyanates and foam chemistry are worth reading. Use the SDS for your exact A and B sides. Do not copy attic-foam re-entry advice as if it were a slab spec.
Can I run slab lift as a weekend side job?
You can try, and the chemicals and the license rules do not get a weekend discount. Drilling still kicks silica. Foam still needs metering and PPE. A side job that crosses your state's contractor threshold is still contracting. If you have a day-job employer, read your moonlighting policy before you wrap a trailer. I would not learn injection on a friend's garage.
How soon can a car drive on a lifted slab?
Foam mixes often take light traffic the same day, sometimes in minutes, but that is manufacturer data, not a law. Slurry needs more time and depends on the mix and weather. I would not release a garage slab until doors clear and elevations hold on a recheck. Write the wait in the contract. If the sheet is silent, you wait longer, not less.
Does slab lift fix expansive clay?
No. It fills a void and raises the panel. Clay can still swell and shrink with water. USGS describes subsidence as surface settlement from movement of earth materials, and your driveway version is usually washout or wet-dry clay at shallow depth. Fix downspouts and irrigation or plan on a return visit. A long warranty on unfixed clay is a gift to the next attorney.
What insurance should a new slab lift crew carry?
Start with general liability written for concrete lifting or polyurethane injection, plus whatever auto covers the rig. If you have employees, add workers' compensation where your state requires it. Some carriers decline residential foam. Get the exclusion list in writing. I would not take a job that needs a certificate you cannot produce this week. Confirm limits with the owner and your broker, not a forum.
Is mudjacking cheaper than foam lifting?
Often the slurry bid lands lower on easy exterior slabs because the material is cheaper and the gear is simpler. Foam can win on interiors, tight access, and weak soils that cannot take extra weight. Nobody publishes a trustworthy national price series for either method. Bid both only if you actually own both systems. A cheap slurry mess in a finished garage is not cheap.
Can you lift a garage slab that is tied to the foundation?
Sometimes the floating apron will move and the structurally tied section will not, or it will crack at the cold joint. That is a site call, not a slogan. If the foundation is rotating, stop and bring an engineer. Slab lift is not underpinning. I would not take that as job one. Write what will not move before you drill.
How do I know which license class to apply for?
Open your board's classification list and ask staff, in writing, whether polyurethane injection under existing slabs sits in concrete, masonry, a limited specialty, or a general contractor class. California's published descriptions do not use the words slab lift. Arizona, Colorado cities, and Alabama do not copy each other. Apply for the class they name. Do not invent a title because a trainer used it.
What is the first piece of gear I should buy?
A rotary hammer, a laser or tight level, PPE that matches the SDS, and a notebook. Rent the proportioner until you know you will keep shooting foam. Cold-weather heaters matter more than a wrap. I would not finance a second chemical system until the first one is paid for and you can stop a lift on purpose.
Do I need a CDL to tow a foam trailer?
Maybe. It depends on the loaded weight of the trailer and tractor and on your state's CDL thresholds, not on the word foam. Weigh the actual rig. Confirm with your DMV. A pickup and a light trailer is a different paper problem than a heavy heated plant. Do not guess from a forum post about someone else's axle count.
Are private slab lift certificates a license?
No. A vendor training badge can be useful for mix control. It does not replace a contractor license, a city business tax certificate, or workers' compensation. Boards do not treat a weekend school as statutory authority. If someone sells you a national slab lift license, walk away. Confirm credentials with the board that can fine the job.
Sources
- OSHA 29 CFR 1926.1153 Respirable crystalline silica: Construction silica PEL is 50 μg/m³ as an 8-hour TWA, with a 25 μg/m³ action level, and Table 1 specified controls for drills.
- OSHA 29 CFR 1910.1200 Hazard Communication: Employers must run a hazard communication program and provide access to SDSs for hazardous chemicals such as foam components.
- OSHA 29 CFR 1926.701 Concrete and masonry construction, general requirements: Construction loads may not be placed on concrete unless a qualified person determines the structure can support them.
- NIOSH Alert 96-111 Preventing Asthma and Death from Diisocyanate Exposure: Diisocyanates are widely used in flexible and rigid foams and are linked to asthma and other serious health effects.
- California Business and Professions Code section 7048: California's contractor licensing chapter does not apply to a project whose aggregate contract price is less than $500, with statutory conditions.
- California Business and Professions Code section 7028: It is unlawful to engage in contracting without the required California contractor license.
- IRS Apply for an Employer Identification Number (EIN) Online: The IRS issues EINs through its online application at no cost.
- NIOSH Pocket Guide to Chemical Hazards, 4,4'-Methylenediphenyl diisocyanate: MDI, a diisocyanate used in polyurethane systems, has a dedicated NIOSH pocket guide entry with exposure numbers.
- OSHA 29 CFR 1926.95 Criteria for personal protective equipment: Employers must require appropriate PPE where there are occupational hazards.
- CSLB Description of Classifications: California publishes contractor classification descriptions and does not list a classification titled slab lift.
- Florida Statute 489.113 (2023): A person who is not certified or registered shall not engage in the business of contracting in Florida.