Slab foundation building in Concord CA - a house slab built to your engineer's plan
Got house plans that call for a slab? We build it on a packed base, to the engineer's design, and explain the choices before you sign.
- Licensed and insured.
- Free in-person estimates.
- Expect a reply within 1 business day.
What goes into building a slab foundation in Concord?
Slab foundation building in Concord means pouring the concrete slab your house sits on. It's laid right on the ground with no crawlspace beneath, which the trade calls a slab-on-ground, and it's built to your engineer's design so it carries the walls and floors for decades.
Most people who call me have a house, an addition or a garage on paper and a lot that's still dirt, and they want to know what they're signing up for. The price mostly moves with the slab's size, how thick it is and how much steel the plan calls for, which slab type the engineer picked, and how much dirt has to move to get a flat, packed pad. The schedule turns on the engineer's plans, the city or county paperwork, the weather on pour day and the curing time, which is the wait while the concrete hardens and gains strength before anyone builds on it. Once I've walked the lot with you, the written estimate puts your own numbers on all of that.
How do you know it's time to build a slab foundation?
Plans that show a slab
Your architect or engineer drew the house, addition or garage on a slab, and now those plans need a crew. Waiting until the framer is booked squeezes everyone, because the slab needs its curing time before walls go up on it.
An old slab cracking apart
A garage or outbuilding slab with wide cracks, one side lower than the other or doors that start to stick usually means the base under it settled or water got underneath. Waiting lets the gap keep growing, and past a point a new slab makes more sense than patching the old one.
Water pooling at the walls
Puddles that sit against a slab edge after rain, or damp spots inside, usually mean the ground falls toward the building instead of away from it. Every storm softens more of the soil the slab sits on, so a new slab or addition is the time to fix the grade.
How we build a slab foundation
I start with the engineer's design and the soils report, because those set the slab type, the thickness and where the steel goes, and I make sure you understand which slab type your plan calls for and why before we dig. Then we dig out and pack the subgrade, the soil the slab sits on, so it doesn't settle later, and we check that the ground falls away from where your walls will stand. We set the forms, place the rebar, the steel bars that hold the concrete together if it cracks, and pour early in the day so the top doesn't dry too fast in the heat and turn dusty. If there's one place to spend money, it's that base, even though nobody sees it once the concrete is down, because a nice finish on a poorly packed pad is still a slab that settles.
Not every house sits on a slab, so if your engineer drew a raised floor with a crawlspace, that's our foundation installation work instead. Small property owners putting up a shop or office often need paving too, and we handle concrete parking lot building so the lot and the building slab drain the same way.
A new house slab
This suits a ground-up home, and it's the biggest version of the job. It follows the engineer's design and soils report most closely, because the whole house rests on it.
A slab for an addition
This suits a new room or wing next to the house you already have. The new slab has to meet your existing floor at the right height, so the step between rooms is the one you planned and not one you trip on.
A garage, shop or ADU slab
This suits a detached garage, a workshop or an ADU, a backyard cottage someone can live in. If people will live or work inside, it gets the same care as a house floor.
Get a written estimate for your slab foundation
Send the form and we'll reply within one business day to set a time. I'll come out, look at the lot with you and give you a free estimate in writing, with no obligation to go ahead.
(925) 536-0945- Based in
- Concord, CA 94519
- Hours
- Mon–Fri: 6 AM–11 PM, Sat–Sun: 8 AM–9 PM
What happens when you call about a slab foundation in Concord?
Here's how a slab job runs from your first call to the day we walk the finished slab together, with me there at each step.
Call or send a message
Call (925) 536-0945 or send the form with your lot address and a rough slab size, and we'll set a time for me to come out. If you have the engineer's plans or a soils report, keep them handy.
Walk the lot together
I look at the site with you and explain the slab type, the base and the choices that move the price. You get the estimate in writing, so you can read it over at home and ask anything before you decide.
We handle the city side
Once you're set, we sort out what the city or county wants for your address. That happens before any work starts on site.
Build the slab, then walk it
We dig, pour and finish with me on site. When it's done, we walk the slab with you and go over the curing wait before anyone builds on it.
Why Concord homeowners call King Concord Concrete Works for slab foundations
The owner writes every estimate
The person who looks at your lot and writes the estimate is me, and I'm the one on site with a small crew of form setters and finishers. The promises in your estimate come from the person pouring your slab.
Choices explained before you sign
I learned concrete on my own place and on other people's crews before starting this business in 2020, and I'd rather you understand the job than take my word for it. You'll know what each choice means over the years, cracks and upkeep included, before anything gets signed.
Licensed and insured for slabs
We're licensed and insured. California's Contractors State License Board requires a license whenever a building job's labor and materials total $1,000 or more, and a house slab is well past that line.
When you're ready to talk through your plans, send us a message or call (925) 536-0945.
Building a slab foundation in Concord and nearby cities
Before anything happens on site, someone has to find out what the city or county wants for your lot, and that's us. In Concord, the city's Engineering Division issues separate grading and encroachment permits when a project moves soil or reaches into the public right-of-way, the street and the strip along it that belong to the public. Whether your slab needs those or a building permit isn't something I'll guess at over the phone, so we check with the city or county that covers your address and handle the permit paperwork when one is needed. The city also doesn't pass building permit applications along to the fire district, County Health or the Contra Costa County Sewer District, so new houses and other projects that call for their review need a separate application to each one.
Lots inside a state hazard zone need geologic and engineering investigations before construction begins, and those can turn up ground failure risk and how to deal with it. I won't say whether your lot is in one until I've seen the address. We run the same checks on slab jobs in Pleasant Hill and Martinez, because every slab starts with what's under it.
Questions about slab foundations in Concord
How much does a concrete slab foundation cost in the Bay Area?
A reinforced concrete slab in the Bay Area usually costs about $9 to $16 per square foot. That's the going rate around here, not our price, and a house foundation runs thicker than the 4 to 6 inches typical of floors, driveways and patios, so expect a foundation quote to reflect that. Your own figure comes from the written estimate after I've seen the lot and the plans.
How long does a new concrete slab take to cure before I can walk on it?
You can usually walk on a new slab within 48 hours, but concrete takes a month to fully cure. Plan the rest of your project around that month, and we'll go over where it falls in your schedule when I write the estimate.
Is it normal for a new slab foundation to crack?
Yes, some cracking is normal. National design guidance for slabs says to expect some cracking and some curling, where the edges lift a little as the top dries faster than the bottom, on every project. I tell you that up front so it doesn't worry you later, and at the estimate I'll explain how your plan handles it, including control joints, grooves cut so cracks fall along lines chosen ahead of time, where the plan calls for them.
How do I find out which permits my Concord slab project needs?
Concord's Project Pal tool shows which permits a project requires, gives zoning information and estimates the permit fees. It's a handy first look before you call, and you can bring what it shows to the site visit.
What is the best slab type for a house on soil that shrinks and swells?
The post-tensioning industry's trade group calls post-tensioned slabs a cost-efficient, high-performance answer for home foundations on soil that swells when wet and shrinks as it dries. In a post-tensioned slab, steel cables run through the concrete and get pulled tight after the pour, squeezing the slab so it holds together as the ground moves. Your engineer picks the slab type from the soils report, so ask which type the bid uses and why it suits your soil.
Do I need a vapor barrier under a slab foundation?
Concrete industry guidance calls for a vapor retarder, a plastic sheet laid directly under the slab, beneath all interior floor slabs. It keeps ground moisture from working up into your floors, so ask whether the bid includes one.
Foundation and paving work that goes with a slab
Foundation installation
When your plans call for a raised floor with a crawlspace, footings and stem walls take the slab's place, and we build those to the engineer's drawings too.
Concrete parking lot building
Property owners adding a shop or building often need paved parking around it, and pouring that lot with the same crew keeps the grades and drainage working together.
Cities where we build slab foundations
King Concord Concrete Works is based in Concord, California, and builds slabs across the 12 cities listed here, including Walnut Creek and Antioch. If your city isn't on the list, call and ask.
Concord, CA
Get your slab foundation priced in writing
Getting a concrete contractor's eyes on your plans before they're final can catch a question while it's still cheap to answer.