Concrete contractor in Altadena, CA - driveways, patios and rebuild slabs
Cornerstone Sierra Madre Concrete pours driveways, patios, walls and foundations for Altadena homeowners, from small repairs to full rebuilds after the Eaton Fire. We're based nearby in Sierra Madre, so Altadena is close to home for our crew.
- Fully licensed and insured.
- Free quotes on site.
- Replies within 1 business day.
Older homes and rebuild lots across Altadena
Altadena isn't a city of its own. It's an unincorporated community, so Los Angeles County acts as its local government and issues the permits a city hall would handle elsewhere. The streets hold a lot of older homes, and the county's planners count landmarks, listed properties and a pending historic district here, so we often pour new concrete beside walks, steps and walls that have been in place for generations. Since the Eaton Fire in January 2025, a lot of what we're asked about here is rebuilding, from breaking out a burned slab to pouring a new foundation. We do the same work a few miles east in Sierra Madre and next door in Pasadena.
That mix shapes the job. A driveway that has settled for decades, or a slab that sat under a fire, usually has to come out completely, and we'd rather find that out at the estimate than after the pour.
Our services in Altadena, CA
- Concrete driveway building
Older Altadena driveways often sink because they were poured on loose dirt. We break out the old slab and pack a firm base under the new one.
- Foundation installation
Rebuilding a burned house here often starts with what's left of the old foundation. We check what can stay and handle the foundation installation your new plans call for.
- Concrete retaining walls
Sloped Altadena yards often need a wall so the patio or driveway has level ground. We build them with rebar, steel inside the concrete, and a drain path behind them.
- Concrete steps construction
Older homes here often have front steps that have pulled away from the porch. We tear out the loose ones and pour new steps on solid footings.
- Concrete patio construction
Many Altadena backyards are being redone, and a patio usually comes first. We slope it away from the house so water doesn't pool by your walls.
- Concrete cutting
Old slabs on rebuild lots often have to come out beside walks and walls that are staying. We saw clean lines so what comes out doesn't crack what stays.
What Altadena lots ask of new concrete
Plenty of Altadena lots slope down from the mountains, so water crossing your yard has to go somewhere, and a new slab can steer it right at the house if nobody checks first. Before we set forms, we look at where water runs now and pitch the driveway or patio away from your walls. Then we dig out the soft dirt and pack the subgrade, the ground the slab sits on, because concrete only stays flat as long as what's under it does. It's like setting a fence post. Pack the hole and it stands for years, but skip that and it leans by next season. We also cut control joints, shallow grooves that give the slab a planned place to crack, since all concrete cracks a little and it's better on a line we picked. The base is the part you'll never see once it's poured, and it's the last place I'd cut to save money.
Rebuild lots are their own kind of job. The price usually turns on how much old or fire-damaged concrete has to come out, how big the new slab is and how easy the lot is to reach, while the schedule turns on the county's permits and inspections and on curing, the wait while fresh concrete gains strength before it can carry weight. Before work starts, we look into what your job needs from the county and handle any permit application as the licensed contractor, walking you through each step.
Get a free on-site estimate for your Altadena concrete
We get back to you within one business day to set a time, and then I come out to your Altadena home myself to look at the job and write the estimate. It's free and there's no obligation. If you go ahead, our crew does the work and I'm on site running it.
Driveways, patios and walls
Altadena concrete questions answered
How do I find out if my concrete project in Altadena needs a permit?
LA County Public Works issues permits in Altadena, because it's unincorporated and there's no city building department. The county's permit categories name patios, retaining walls and grading work, and you can type your address into the Public Works permit site and click Find Services to see which office covers your property. Once a permit is issued, the county's guidance says to request the first inspection within 12 months, and inspections every 6 months after that keep it active. That's the part we handle for you.
What counts as a like-for-like rebuild in Altadena after the Eaton Fire?
LA County Planning calls it like-for-like when the new structure has the same size, location and land use as the one that was legally there before. Changes can be approved if they add no more than 10 percent or 200 square feet, whichever is greater, to the floor area, size, height or footprint. Go past that and the rebuild has to meet the county's current standards, including the Altadena Community Standards District and a front yard setback of at least 20 feet. If you're not sure where your plans land, the county's Altadena One-Stop Permit Center offers a free virtual appointment on rebuilding plans and permits.
What does a contract for a fire rebuild in Altadena have to include?
It has to be a written, fixed-price contract that says who gets the permits and gives a completion date, and the down payment can't be more than $1,000 or 10 percent of the total price, whichever is less. The state's contractor licensing board treats rebuilding after a wildfire or another declared disaster as a home improvement project, and it requires a written contract for any of those over $500. You can check the board's rules on home improvement contracts before you sign anything.
Do I need a licensed contractor to pour concrete at my own home in Altadena?
Not always, because the state licensing board exempts a homeowner improving the home they live in as their main residence, but only when every condition is met. The work has to be done before any sale, you have to have lived there for the 12 months before it's finished, and you can't have used the exemption on more than two structures in any three-year period. If you'd rather hand it off, we're fully licensed and insured, and I'm glad to explain the job either way.
What is the best way to pour a driveway near an oak tree in Altadena?
Find out first whether the tree is protected, because LA County protects oaks and other native trees depending on location, and work inside a protected tree's zone normally needs a permit. The exception applies only where a legally established structure stood in that zone on the day a disaster damaged or destroyed it. We look at this during the estimate, since a protected zone can change where the driveway runs and how we dig the base.
How much does concrete work cost in Altadena?
Your price comes down to the size of the job, how thick the slab has to be, how much old concrete comes out first and the finish you pick. A driveway is poured thicker than a patio because it carries a car, and a broom finish, a lightly brushed texture that grips underfoot, costs less than stamped or decorative work. I write your own figure on site, after I've looked at the ground, the drainage and how we'd get equipment in. Call (626) 828-0332 or use the form to set that up.