Concrete Leveling in San Marcos: Mudjacking, Foam or Replacement?
A sunken driveway panel or a walk with a toe-catching lip has three possible fixes. Raise it with slurry, raise it with foam, or break it out and pour it again. This guide is about choosing between them.
Before you read on: San Marcos Concrete Services doesn't do concrete leveling. We don't mudjack, slab jack or foam-lift driveways, walks or patios. We replace broken panels and pour new flatwork, and we wrote this so you can judge a leveling bid on your own and tell when replacement is the honest answer.
- What is concrete leveling?
- Concrete leveling (also called concrete lifting, slab jacking or concrete raising) pumps material under a sunken slab through holes drilled in it. The material fills the void and raises the slab back toward grade.
- Mudjacking or foam?
- Mudjacking pumps a cement-and-soil slurry through larger holes. Polyurethane foam goes in through small holes, weighs far less and takes traffic sooner, but costs more per square foot.
- When won't it work?
- When the panel is broken, was pushed up by a root or swelling clay, sits over a leaking pipe, or has already been lifted once and dropped again.
- What does it cost?
- HomeAdvisor's 2026 national figures: $3–$6 per square foot for mudjacking and $5–$25 for foam, with most projects $662–$1,884. More published ranges below.
- Why do slabs sink here?
- Mostly water and clay. East of the Balcones Escarpment the soil is Blackland clay that shrinks in a drought, and a downspout or a leaky sprinkler can wash the base out from under a panel.
What Concrete Leveling Does, and Why Slabs Sink in San Marcos
A driveway or walk is only as flat as the ground under it. When the ground drops away, a slab of concrete doesn't sag like a floor would; it bridges the gap for a while, then tips or settles into it. Leveling puts something back into that gap and pushes the slab up with it. That only makes sense once you know why the gap opened. Here is what that usually looks like:
- Clay that shrinks in a drought. USDA describes Houston Black, the clay across the Blackland side of Hays County, opening cracks from half an inch to 4 inches wide and a foot or more deep, and keeping them open 90 to 150 days in most years. A walk poured on it in a wet spring can be sitting on air by August.
- Backfill along the house. The strip of soil dug out and put back beside a new foundation is usually the loosest ground on the lot. Walks, patios and garage aprons poured over it settle toward the house.
- Downspouts and sprinklers. A gutter that empties at a slab edge, or a sprinkler head soaking one panel, washes fine soil out through the joints a little at a time. That is the void in the drawing.
- Tree roots. They work both ways: roots dry the clay under a slab so it drops, or grow under a panel and push it up. Only the first is a leveling problem.
- A leaking pipe. A water or drain line under a slab can wash out its own hole. ASCE's Texas foundation guidelines list leaking plumbing among the causes of soil movement under houses; the same water does the same thing under a walk.
- Hill Country lots. West of the escarpment, USDA's Comfort series puts limestone 10 to 20 inches down, so the ground itself moves less. Slabs there tend to sink where a lot was built up with fill to level it. Texas State's Freeman Ranch soil survey notes that some clays on that side, like Krum and Medlin, still shrink and swell.
Mudjacking vs. Polyurethane Foam vs. Replacing the Slab
Mudjacking and foam lifting are both kinds of slab jacking: drill, pump, raise. They differ in what goes under the slab. Missouri DOT's maintenance manual, written for highway slabs but describing the same technique, mixes soil or loam with portland cement and water, and allows sand, lime, limestone or mineral filler in place of the soil. For foam, the same manual calls for a "high density polyurethane" that expands as it goes in. A third option, sandjacking, raises the slab with jacks and fills the gap with dry sand or limestone (HomeAdvisor).
| Mudjacking | Polyurethane foam | Replace the panel | |
|---|---|---|---|
| What goes under | Cement-and-soil slurry | Expanding foam | A new compacted base, then new concrete |
| Holes in the slab | Larger: about 2⅝ in on MoDOT highway work | Small: 9/16 to 3/4 in per MoDOT | None; the old panel goes |
| Weight on soft soil | Heavy; adds load to the ground that let it sink | Far lighter than cement (Angi) | Same slab weight on a rebuilt base |
| Back in use | After the slurry sets | Foam can cure in about an hour (HomeAdvisor) | Days, while new concrete cures |
| Price | Lowest per sq ft | Up to about four times mudjacking (Angi) | Usually the most |
| Works on | Whole panels over a big void | Whole panels, tight spots, walks where patches show | Broken, root-heaved or twice-sunk panels |
| Doesn't fix | The water or clay that caused it | The water or clay that caused it | A bad drainage pattern, unless that's fixed too |
Green: an advantage. Red: the weak point. Amber: depends on the job. The two hole sizes are Missouri DOT's figures for pavement; residential crews vary, so ask for the diameter in writing.
None of the three makes a 20-year-old slab new. A lifted panel keeps its stains, its cracks and a row of round patches where the holes were. A replaced panel is crisp and flat but starts out lighter in color than its neighbors. If you're asking which looks better, that's usually replacement; if you're asking which costs less and keeps the concrete you have, it's lifting.
Will Leveling Work on My Slab? Signs It Needs Replacing
Lifting only works on a slab that is in one piece and went down. Tick whatever is true of yours:
- Broken panels. Missouri DOT's manual puts it bluntly: "badly cracked or broken slabs cannot be raised effectively." Each piece rises on its own and the cracks open wider. A broken panel gets cut out at the joints and poured back, which is concrete repair work we do.
- Root heave and clay swell. Pumping material under a slab that's already too high makes it higher. A root-lifted panel is ground down or replaced after the root is dealt with; a slab heaved by wet clay usually settles back some as the clay dries.
- A leak. Lifting over a leaking pipe pumps material into a hole the water keeps making. Get a plumber to test the line first.
- Lifted once already. A slab that dropped again after a lift is telling you the cause was never fixed. A second lift on the same cause will likely go the same way.
- A worn-out surface. Raising a slab doesn't touch its surface. If the top is failing everywhere, replacement may cost about the same and last longer. On a slab that is level and sound, a cement overlay is the other option; the concrete resurfacing guide covers when one holds.
- The house. Lifting a house slab is a structural repair designed by an engineer. That's foundation repair, not flatwork leveling.
Concrete Leveling Cost: Mudjacking and Foam Prices Compared
These are published national figures, each credited to its source. We don't do leveling, so none of them is our price and we can't quote the work. Use them to check whether a bid is in the normal range.
| Leveling job | Published range | Source |
|---|---|---|
| Concrete leveling, most projects | $662–$1,884 (average $1,242) | HomeAdvisor, June 2026 |
| Mudjacking, per sq ft | $3–$6 | HomeAdvisor, June 2026 |
| Polyurethane foam raising, per sq ft | $5–$25 | HomeAdvisor, June 2026 |
| Sandjacking, per sq ft | $3–$8 | HomeAdvisor, June 2026 |
| Driveway leveling | $600–$3,000 | Angi, Sept. 2026 |
| Sidewalk leveling | $300–$1,800 | Angi, Sept. 2026 |
| Patio leveling | $600–$3,200 | Angi, Sept. 2026 |
| Garage floor leveling | $1,100–$2,200 | Angi, Sept. 2026 |
| Pool deck leveling | $300–$600 | Angi, Sept. 2026 |
| Concrete steps leveling | $200–$500 | Angi, Sept. 2026 |
| Minimum trip fee on a small job | about $150 | Angi, Sept. 2026 |
HomeAdvisor's worked examples show how the methods compare on one job. For 100 square feet of sidewalk it lists $320–$650 to mudjack, $650–$2,700 to foam-jack, and $1,300–$2,600 to replace. A 200-square-foot section of driveway runs $650–$1,300 to mudjack and $1,500–$3,200 with foam.
What moves a leveling price: how big the void is (a deep one takes a lot more material), how far the slab dropped, how many holes it takes, access for the rig's hoses, and whether a warranty is included. HomeAdvisor names materials as the biggest variable, "followed by the length and terms of any warranties offered." Lifting under a house is priced differently; see the foundation repair cost table.
Links: HomeAdvisor concrete leveling cost, Angi concrete leveling cost.
Driveway Leveling: Garage Aprons, Approach Joints and Heavy Loads
The panel that drops on a San Marcos driveway is usually the one at the garage door. It often sits on backfill against the foundation, it catches whatever runs off the roof and the drive, and once it tips, it sends that water at the garage slab. Raising it restores the slope away from the door, which is the main reason to do it soon.
The approach. The stretch between the street and your property line is in the city's right-of-way and built to its own standard detail (433S-A-SM). A new approach needs the city's Access Driveway Permit. We found no city page saying whether lifting an existing approach panel needs one, so ask Planning & Development Services (512-805-2630) before anyone drills it.
Heavy loads. HomeAdvisor's guide says mudjacking lasts longest where the surface doesn't carry a constant heavy load. If an RV, a work truck or a trailer lives on that panel, ask the bidder how the method holds up under it.
When panels are broken across most of the drive, or the base has gone soft everywhere, lifting one section at a time just spreads the cost out. That's concrete driveway replacement, and our driveway page covers when a drive needs it.
Sidewalk Leveling and Trip Hazards: Who Fixes the Public Walk
In San Marcos, the walk in front of your house is mostly yours to keep up. City code Sec. 74.122 makes it unlawful to let the sidewalk in front of property you own or control "become or remain in any condition which might endanger a person or interrupt a person's free passage." The Public Works streets FAQ says sidewalks in the right-of-way are the adjacent owner's responsibility for routine maintenance, "but the City may perform repairs in certain circumstances." If you're not sure the walk is in the right-of-way, the city says to call Public Works at 512-393-8036.
Sources: City of San Marcos, Sidewalks (Sec. 74.122), Public Works streets FAQ.
So call Public Works before you pay anyone to lift or replace a panel along the street. The city may take care of it, and if it won't, you'll know the job is yours before you pay for it.
How big a lip is a problem? The federal ADA standards for accessible routes (section 303) allow a change in level up to ¼ inch with no treatment, require a bevel no steeper than 1:2 between ¼ and ½ inch, and treat anything over ½ inch as a ramp. A private front walk isn't held to that, but it's a fair yardstick: under ¼ inch, leave it; up to ½ inch, grinding a bevel is often enough; past that, the panel needs raising or replacing.
Check the cross slope after a lift. The city's sidewalk detail (432S-1-SM) allows 2% sideways tilt at most. A panel raised from one side can end up level at the joint and tipped across the walk, which is hard on wheelchairs, walkers and strollers. A 2-foot level and a ruler will tell you.
A panel lifted by a tree root is the opposite problem and gets ground down or replaced, not jacked; the concrete sidewalk page walks through those options and the city's specs for a new panel.
Patio, Pool Deck, Garage Floor and Step Leveling
Patios that tip toward the house
A patio that settles over the backfill ends up draining at the foundation. Raising it can put the fall back where it belongs, away from the house. Check it with a level after the work, not just by eye. Building a new one instead? See concrete patio planning.
Pool deck walks and coping edges
Pool plumbing, skimmer lines and electrical bonding often run right under the deck. Anyone drilling and pumping there should know where those lines are first, and material that finds an open trench can travel along it. Ask how the bidder will locate the lines. If the deck is level but the surface or the coping joint is failing, that's a different job; see pool deck resurfacing.
Garage floor slabs: detached vs. attached
A detached garage slab, or one section of a garage floor, is flatwork: HomeAdvisor puts mudjacking a single section at $550–$1,100. In an attached garage the floor is often part of the house foundation, and that's a question for an engineer first.
Steps and porch landings
Steps are thick. HomeAdvisor notes they often need holes drilled around the sides or very long holes through the treads. A step block pulling away from the house may need a new footing instead; that's concrete step repair.
How Slab Jacking Works, Step by Step
The process a good leveling crew follows, with the checks worth watching for. The pumping details come from Missouri DOT's maintenance manual for highway slabs; a residential job is smaller but works the same way.
- Before any drilling
Find and fix the drainage
Downspout extensions, a repaired sprinkler line, a plumber's test if a leak is possible. Lifting comes after the cause, not before.
- Same visit
Mark the lines under the slab
Sprinkler pipe, water and gas lines, pool plumbing. A drill bit through a line is a new leak under a freshly lifted slab.
- Drilling
A hole pattern across the sunken panels
MoDOT describes mudjacking holes "generally 2 5/8 in. in diameter" and foam injection holes of 9/16 to 3/4 inch. Holes near a joint are set back from it.
- Pumping
Raise the slab a little at a time
MoDOT's rule is no more than ¼ inch at any one hole per pumping, moving hole to hole, with a string line or level on a long slab and a straightedge at each joint.
- Right after
Patch the holes
Holes are cleaned out and filled with cement mortar (MoDOT: one part cement to three parts sand). They stay visible.
- Same day
Seal the joints and cracks
Flexible sealant in the joints, and between the slab and the house, so the next rain doesn't wash out the same base. Ask whether this is in the price; it isn't always.
- After a dry summer
Recheck the joints and the slab
Lay a straightedge across the joints after the first long dry spell and again after a wet season. A slab that's moving again is telling you the water isn't fixed.
Concrete Leveling Near Me: What to Ask Before You Hire
Whoever you call for leveling, get these answers on paper. A good leveling company will have them ready.
| Ask | A real answer | Keep looking if… |
|---|---|---|
| What material, exactly? | Slurry mix or the named foam product, and how much they expect to use | "Our special mix" |
| How many holes, how big, where? | A count, a diameter and a sketch, plus how they're patched | No number until the day of the work |
| Filling a void or lifting? | Which panels get raised, by roughly how much, and which only get the void filled | "We'll make it level" with no target |
| Are joints sealed afterward? | Yes, with flexible sealant, priced in the bid | "That's extra" after the job is done |
| What does the warranty cover, if one is offered? | Written terms: how much re-settling, how long, and whether it transfers when you sell | "Lifetime" with nothing written down |
| What if a panel cracks during the lift? | Stated in the contract, including who pays to replace it | A shrug |
One more question to ask yourself: is the bid fixing the cause? If nobody mentions the downspout pouring onto that panel, the lift is on borrowed time.
DIY Concrete Leveling: What a Homeowner Can and Can't Do
Raising a slab yourself is mostly off the table. It takes a pump or a foam rig and someone who has watched slabs crack. Angi recommends DIY leveling only in rare cases, like a small step or a single walkway slab, and says to avoid leveling concrete that has already cracked or split.
Bagged self-leveling compound is a different thing. It doesn't raise anything; it builds up the low side of a surface. Angi says it suits a slab that has sunk less than an inch, and only after the cause is fixed. Outdoors on a walk, thin compound at the edge of a lip is the part that breaks off first.
What you can do well, and what decides whether any lift lasts:
- Extend downspouts away from walks, patios and the drive, not just away from the house.
- Fill washouts along slab edges with soil and pack it so water runs away from the concrete.
- Clean and seal open joints with a flexible sealant made for concrete.
- Mark the panel corners with a pencil line on the house or a stake and measure them each season. That record tells a leveling company, or a replacement crew, whether the slab is still moving.
Keeping a Leveled Slab Up: Downspouts, Sprinklers and Joints
On Blackland clay, no lift is permanent if the ground under it keeps getting wet and dry in patches. Water management decides how long the lift lasts, and it costs less than the leveling did:
- Roof water. ASCE's Texas guidelines want downspouts discharging "well past the edge of the foundation." Do the same for a walk or patio that runs along the house: the water should land on soil that drains away, not at a slab edge.
- Sprinklers. Aim heads at the lawn, not the walk, and look for a soggy patch beside a panel. That's often a cracked fitting under the turf.
- Even moisture on the east side. Clay that stays evenly damp moves less than clay that bakes and floods. In October 2026 San Marcos is in Stage 3 drought rules, which allow foundation watering one day a week by soaker hose, drip line or hand-held hose. A soaker line along the house helps the walk beside it too.
- Joints kept closed. The city's sidewalk detail cuts control joints ¼ inch wide and ¾ inch deep. An open joint is where water and fine soil get in and out, so keep it sealed.
That's also the honest case for replacement now and then. If the drainage can't be fixed, because the walk sits in the only path the water has, lifting the same panel every few years costs more than regrading and pouring it once. When that's the answer, it's work our San Marcos concrete contractor crews do.
Mudjacking and Foam Lifting Questions
Do you level or lift concrete?
No. We don't do mudjacking, slab jacking or foam lifting on driveways, walks, patios or any other flatwork, so we can't quote it. What we do is the work on either side of it: cutting out and replacing a broken panel (concrete repair), rebuilding a drive or walk, and repairing a house foundation that has moved.
Is foam better than mudjacking?
Not always. Foam leaves smaller holes, weighs far less and takes traffic sooner, which matters on soft soil and on walks where the patches show. Mudjacking costs less per square foot and fills a big void with something solid. On a large void under a driveway panel that isn't going anywhere, slurry can be the sensible buy.
How long does a leveled slab stay level?
Published figures are loose. HomeAdvisor's guide gives a properly done mudjacking job 8 to 10 years in one place and 5 to 10 in another, and says foam lasts longer. On shrink-swell clay the material is rarely what fails first. If the water that washed out the base is still running there, any lift can drop again.
Will the drill holes show afterward?
Yes. They're filled with a cement mortar and stay visible as round patches that won't match the old concrete exactly. Foam holes are about the size of a coin and easy to miss; slurry holes are bigger. Ask where they'll go before work starts, especially on a front walk.
Can the slab crack while it's being lifted?
It can, which is why good crews raise a slab in small steps and watch it the whole time. A panel that already has a crack running through it is the most likely to split. Before you sign, ask in writing what happens if a panel breaks during the lift.
My sunken garage floor is part of the house slab. Is that concrete leveling?
Treat it as a foundation question first. In an attached garage the floor is often poured with the house foundation, and a drop there can be the foundation moving. A structural engineer should look at it before anyone pumps material under it. Our foundation repair page explains that process.
Slab broken, not just sunk?
We don't level or lift concrete. If a panel needs cutting out and pouring back, a walk or drive needs rebuilding, or the house itself has moved, send the address, what you're seeing and a few photos.