Slab foundation building in Duluth MN - a slab built for your lot and our winters
Building a home, garage or addition and unsure what it should sit on? We plan the slab around your lot, then build it.
- Services
- 16
- Service areas
- 4
Get your slab foundation estimate started
We walk the lot together and talk about the building's size and what it's for.
Request an estimateWhat does it take to build a slab foundation in Duluth?
A slab foundation is a concrete base poured at ground level and designed to carry the whole building, and Duluth Concrete Works builds them in Duluth for new homes, additions and garages by settling the footing depth, the base and the drainage before anything gets poured.
Most people who call us have a building planned and a lot picked out, and what they don't know yet is how deep the edges need to go or what the ground will let them do. The price mostly moves with the size of the footprint, whether the slab sits on full-depth footings or on a shallower edge built to keep frost out, how much poor ground has to come out and be replaced with packed base, and whether radon venting goes in. The schedule turns on the permit and its inspections, the weather, and how wet or frozen the ground is when we're ready to pour. If you're putting up a garage, the same questions come up on a smaller scale. Your own figure comes from the estimate at your site, once I've seen the lot.
How we build a slab foundation, step by step
Before we choose between full-depth footings and a frost protected shallow design, I walk the slope of your lot with you, because the slope has a lot to say about which one fits. On a new home we plan the radon venting into the slab from the first drawing, since laying that pipe before the pour is far easier than adding a system later. Then we dig the subgrade, the ground the slab sits on, down to solid material and pack the base so it won't settle with the dirt, and we set the grades so water runs away from the building instead of toward it. We set the forms and the rebar, the steel that holds the slab together if it does crack, pour early in the day, and cut control joints, shallow grooves that give the slab a straight place to crack, while the concrete is still young. Then we let it cure, keeping it damp and covered so it gets its strength before anyone builds on it. If the budget gets tight, I'd rather we keep the base work and spend less up top, because the base is the one part you can't fix once the walls go up.
Some buildings need more than a slab. If you want a basement or crawlspace, that's foundation installation, with walls on footings below the frost line. For property owners putting up a commercial building, we can pour the slab and plan the concrete parking lot around it so the water from both heads the same way.
What Duluth's permits and wet ground mean for your slab foundation
For a new home, the state requires a building permit and inspections for the radon system that goes under the slab, and the city inspects all work that needs a permit. To find out exactly which permits your project needs, ask the city's building office at City Hall, Room 100, 411 West First Street, 218-730-5240. When a job needs a permit, we pull it and book the inspections. If you'd rather apply yourself, I'll tell you what the city will want to see from us.
One soil survey summary for the area says about half the land stays wet for long stretches, and groundwater sits within two feet of the surface under about three quarters of it, so a site check is the only way to know where your lot falls. That's why I look at where the water goes and plan the base and grades around it before we talk depth. We run the same checks on jobs in Hermantown and Cloquet, and in the other cities around Duluth where we work.
Why call us for a slab foundation
I meet you at the lot
I come out to look at the job and meet with you myself, and I'm on site running it when our crew does the work. The person who heard what you wanted is the one watching the base go in.
Five years of jobs needing thought
I started this business in 2021 after teaching myself concrete and working on other crews, and builders and property owners call us when a foundation needs real figuring out. That's the kind of job I like most, so ask all the questions you've got about slope and water.
Licensed and insured for your project
We're licensed and insured. That's worth checking with anyone you're comparing before they start digging on your property.
Know Minnesota's contractor license rule
The state's labor and industry department requires a residential building contractor or remodeler license from a company you hire directly for work in more than one special skill on a home of one to four units. Asking a contractor which license they hold takes a minute and can save you real trouble later.
- Phone
- (218) 514-2182
- Hours
- Mon–Fri: 7 AM–10 PM, Sat–Sun: 8 AM–9 PM
- Location
- Duluth, MN 55802
The part of this job that deserves the most attention is what's under the slab, so send us your lot details and I'll come out to walk it with you.
Get a slab foundation estimate for your lot
Send your lot address, the building's size and use, and any soil report you have, or call (218) 514-2182. We'll get back to you within one business day to set a time, and I'll come out to walk the lot with you myself. The estimate is free and done at your site, with no pressure and no obligation.
- Phone
- (218) 514-2182
- Location
- Duluth, MN 55802
- Hours
- Mon–Fri: 7 AM–10 PM, Sat–Sun: 8 AM–9 PM
- Credentials
- Licensed and insured.
Frequently asked questions
How deep does a slab foundation have to go in Duluth?
In St. Louis County, which includes Duluth, the state's minimum footing depth for frost is five feet, unless an engineer competent in soil mechanics determines something different. Minnesota's codes also allow a frost protected shallow foundation, which reduces how deep the footing has to go. We sort out which one your building gets after we've looked at the lot together.
How do I know if a frost protected shallow foundation is right for my lot?
Builders' guidance says a frost protected shallow foundation is usually best suited to a slab-on-grade home on a lot with a moderate to low slope. Soil matters too, since state rules allow a structurally designed slab on grade when the ground is sand, or pit run sand and gravel, down to the required footing depth, and an engineer competent in soil mechanics can approve other sand. When it fits, the guidance notes it can go in with one placement of concrete, which speeds up the build.
How much does a concrete slab foundation cost in Duluth?
A concrete slab in Duluth usually costs about $7 to $12 per square foot, which is the going rate in the area for the slab, not our price. A frost protected shallow design can bring the cost down because it means less digging, less concrete and smaller forms, while deep footings, lots of replaced base and radon venting push it up. You'll get the figure for your own building at the estimate.
Does a new home in Minnesota need a radon system under the slab?
Yes, the state requires a new residential building to contain a passive radon mitigation system, which draws radon gas from under the slab and vents it outside. It comes with its own permit and inspections, as covered above, which is one more reason we plan it with the slab from the start.
Can I put a detached garage on a slab in Duluth?
In most cases yes, since state rules let a detached one-story private garage, carport or shed up to 1,000 square feet sit on a slab on any soil except peat or muck. If yours is bigger or attached to the house, that allowance doesn't cover it, so we plan the footings the way we would for a home.
What is the best way to pour a slab foundation in a Duluth winter?
Start with warm ground, because one cold-weather concrete guide says the ground under the slab should be at least 40°F and within 20°F of the concrete's temperature. Frozen ground can be thawed first with ground heaters or blankets. If the ground isn't there yet, I'd rather wait than pour on it.
Related concrete work
Foundation installation
When the plan calls for living space or storage below ground, poured foundation walls on footings take the place of a slab, and this page explains how we approach them.
Concrete parking lot building
A new commercial or multi-unit building usually needs paved parking too, and planning the lot with the slab keeps grades and runoff working together across the whole site.