Foundation concrete for new work - not foundation repair

What is foundation concrete?

Foundation concrete is the new pour that carries a structure: excavated footings, formed foundation walls or piers, and often a slab - for additions, garages, ADUs and outbuildings. It is planned from soils, frost depth, loads and permits. It is not the same service as foundation repair, which stabilises or remediates an existing foundation that has already failed or moved.

Signs you need foundation concrete

• You are adding a room, garage, porch with structural loads, or detached building that needs a real foundation
• Plans call for continuous footings, stem walls, a basement under a small addition, or a thickened-edge slab
• A builder or architect needs a concrete contractor for the foundation package only
• An old shed pad is being replaced with a permitted garage foundation
• You need inspected, documented concrete work for a lending or municipal requirement on new construction

Seeing something not on this list? Browse concrete problems by symptom →

How foundation concrete actually works

1. 1

   Separate "new foundation" from "repair foundation"

   Cracks, settlement, bowing walls and sinking corners on an existing house are foundation-repair problems - piers, stabilization, crack injection. New foundation concrete assumes you are building something that does not exist yet, or replacing a foundation as part of a rebuild under structural direction.

   Watch forA flatwork crew bidding "foundation concrete" to fix a settling house without geotech or structural input. Wrong trade framing.

2. 2

   Plans, soils and frost depth

   Loads, wall heights, soil bearing and climate-driven footing depth come from design documents and local code. Surprises in poor fill or high water table change excavation and may require engineered revisions before concrete is ordered.

   Watch forPouring to "what the neighbour has" without checking permit conditions on your lot.

3. 3

   Excavation, forms and steel

   Footings are dug to design depth on competent material, forms set true, and reinforcement placed with proper chairs and clearances. Anchor bolts and hold-downs for the framing package are located before the pour, not drilled randomly later when possible.

   Watch forSteel lying in the mud at the bottom of the footing. Cover and placement are structural, not cosmetic.

4. 4

   Inspections before concrete

   Most jurisdictions inspect footings and often walls before placement. Pouring without a required inspection is how people pay twice - once to pour, once to expose or replace.

   Watch forPressure to pour Friday because the truck is cheap when the inspector has not signed. Wait.

5. 5

   Place, consolidate, cure

   Concrete is placed, vibrated or otherwise consolidated in walls, finished as specified on slabs, and cured. Cold-weather and hot-weather practices matter more on foundation walls than on a short sidewalk because section thickness and strength timelines differ.

   Watch forAdding water on site to make the mix "easier" until strength suffers. Strength is why you poured a foundation.

6. 6

   Damp-proofing, drains and backfill coordination

   Foundation walls that retain soil often need exterior drainage and damp-proofing or waterproofing before backfill - sometimes by other trades. Sequencing with plumbers for under-slab rough-in is part of the foundation package on many additions.

   Watch forBackfill against green walls with no drain plan. You just built a basement moisture problem.

7. 7

   Coordinate under-slab plumbing and electrical sleeves

   Once concrete is placed, moving a mislocated sleeve is brutal. Plumbing and electrical rough-ins that pass through the foundation package need verified locations against the plans before the truck is ordered.

   Watch forPour day surprises about a missing sewer stub or electrical conduit. Hold a coordination check the day before.

What does foundation concrete cost?

New foundation concrete is bid from plans: lineal feet of footing and wall, slab area, steel, depth, access and inspection complexity. Additions on tight lots cost more per foot than open greenfield pours. Repair of existing foundations is a separate market - do not use new-pour square-foot guesses for pier work.

See the full foundation concrete cost guide - by material, size and region →

If the number is the problem, here are the ways people pay for it →