Ironset Boston Concrete Construction
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Slab foundation building in Boston MA - built for the ground under your house

Planning a new home or addition on a slab? We check your ground and flood map first, then pour a foundation that fits both.

Request an estimate(617) 226-2081
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  • Licensed and fully insured.
  • Free estimates at your property.
  • We respond within 1 business day.

The slab foundation work we take on

  • New slab-on-grade foundations

    A concrete slab poured on packed ground to carry a new house, addition or small building, laid out to match your engineer's plans.

  • Slab foundation repairs and changes

    When an existing slab foundation needs repair, or has to change for an addition or a new layout, we rework it to the engineer's plans.

What does building a slab foundation in Boston involve?

Slab foundation building in Boston means pouring a concrete slab right on prepared ground to carry a new house or addition, or changing or repairing the slab foundation you already have, so the building sits on a level base made for the soil under it.

Most calls come from people planning a new home or an addition, or from landlords with an old slab foundation that needs repair, and the first questions are always cost and time. The price mostly turns on the slab's size and thickness, how much loose fill has to come out before we pour, and whether flood rules shape the design, while the schedule turns on permits, weather and what we find once the ground is open. Your own number comes from the estimate visit, after I've seen the lot.

Slab foundations, from dig-out to finished pour

We start from your engineer's plans and ask about your ground and flood map before pricing, since those shape the whole design. If your plans call for walls instead, see foundation installation.

  • Dig out and pack the base

    We dig out loose dirt and soft spots, then pack the subgrade, the ground the slab rests on, so it holds firm.

  • Grade for drainage

    We check where water runs on your lot and grade it away from the slab, just as we do on a concrete parking lot.

  • Forms and rebar

    We set forms and tie the rebar, steel that holds the slab together as the ground moves, where your engineer's plans place it.

  • Pour, joints and curing

    We pour before the midday heat, cut control joints so cracks follow straight lines we chose, and let it cure before framing starts.

Why Boston owners call Ironset for slabs

I spent years patching slabs and steps on rental buildings around Boston, wondering why they kept failing. I started Ironset in 2023 to build concrete that skips that patching. Call (617) 226-2081 to have me look at your lot.

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  • The person who prices it pours it

    I come out to look at your lot and write the estimate myself, then work alongside our crew while they form, pour and finish, so the person who priced it is on site.

  • Licensed and insured, and easy to check

    We're licensed and fully insured. Massachusetts requires a licensed construction supervisor to oversee certain construction projects, and you can check a supervisor's license with the state before you hire anyone.

  • We won't skimp on the base

    When budgets get tight, people want to cut the base because nobody sees it. I'd rather trim elsewhere, since the base decides how the slab holds up.

What happens after you call about a slab foundation?

Every slab starts with your plans and your lot, so the first visit is about what's under the ground and what's gone wrong there before, not a quick number.

Request an estimate

or call (617) 226-2081

  1. You call or send the form

    Call (617) 226-2081 or send the form with your lot address, and tell us whether your engineer has stamped plans ready yet.

  2. I come out to your lot

    I walk the site, look over your plans and ask what's gone wrong there before, because past cracking and standing water tell me a lot about the ground.

  3. You get a written quote

    The quote shows what goes under and behind the concrete as well as what you'll see, and we line up any permits before our crew starts.

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Get a price on your slab foundation and site prep

Send your lot address, whether it sits in Boston's flood hazard district if you know, and any stamped plans you have. We reply within one business day, and I come out for a free estimate with no obligation.

(617) 226-2081

Slab foundation questions from Boston owners

Do I need a permit to build a slab foundation in Boston?

Yes, Boston's Inspectional Services Department issues the permits to build, change or repair a foundation, and you start the application online and finish it at its office. The foundation permit needs a long form permit already on file and approval from the Boston Water and Sewer Commission, and the city sets the fee at that office visit. If it isn't clear what your job needs, we check with the city instead of guessing.

How much does a slab foundation cost in Boston?

A foundation slab in Boston usually costs about $13 to $19 per square foot, which is the going rate in the city, not our price. Where your job falls depends mostly on what has to happen under the slab before the pour, and the estimate spells that out for your lot.

Can my house have a basement in Boston's flood zone?

Not a fully buried one, because in Boston's Flood District a residential building may not have a basement with floors below grade on all sides. Owners building there plan a slab or another foundation without a fully buried basement, so it pays to check your lot's flood map before the design is set.

How do I build a shallower slab foundation in Boston?

One option is a frost-protected shallow foundation, a design a national builder's guide describes as most suitable for slab-on-grade homes on lots with moderate to low slopes. The guide says a slab-on-grade version can go in with one placement of concrete, which can shorten the build. Whether it fits your lot is a question for your engineer, and one I'm glad to talk through at the estimate visit.

Do I need a soil report for a foundation in Boston?

On projects over 35,000 cubic feet, yes, the city's building permit checklist asks for a geotechnical report, an engineer's study of your soil, with a foundation recommendation from a Massachusetts Registered Professional Engineer. When there's a report, we build to what it recommends.

How do I get ready to apply for a foundation permit in Boston?

Start by gathering what the city asks to see for new construction: the total work planned, a total cost estimate covering labor and materials, and plans stamped by a licensed professional. The foundation permit also asks for proof you've been working with a licensed rodent control exterminator, so book one before you apply. For one- and two-family projects the city asks for current licenses for all contractors and a Home Improvement Contractor registration, so ask any contractor for both up front.

Slab foundation building on Boston's fill and flood land

If your lot is in the city's Flood Hazard District, which follows FEMA's flood map, a long form permit gets an added flood hazard plan review, so we plan the slab with that review in mind from the first conversation. We're based in Boston and work across the city and the cities around it, and we ask the same flood questions on jobs in Chelsea and Winthrop. If you don't see your city listed, just ask us.

Parts of Back Bay, Lower Beacon Hill, the South End, Fenway, Chinatown, Bay Village and East Boston sit on filled land, and fill and soft organic layers aren't fit to carry footings for any significant building. On those lots we want to know what's down there before we price, because it decides how deep the support goes and what the slab rests on.