Concrete foundations: new foundations and foundation repair in Connecticut
Free estimate on new foundations, footings and foundation crack repair, priced from your plans or a site visit.
- Footings 42 inches below grade
- Poured walls, dampproofing and footing drains
- Crack injection for leaks and structural cracks
How we build a new foundation
We pour foundations for new homes, additions, garages, sunrooms and porches, and we repair the ones that leak or crack. New work starts with your plans and the soil. Repair starts with figuring out whether a crack is a nuisance or a symptom.
If a wall is bowing, a crack keeps widening, or the house is moving, you need a structural engineer before you need us, and we'll say so. Most cracks we see are shrinkage cracks that let water in, and those are usually a one-day fix.
- Footings
- 42 in. below grade on undisturbed soil, sized to the load and the soil
- Inspection
- Footing inspection before the pour where the building official requires it
- Walls
- Poured concrete, typically 8 or 10 in., reinforced per the plans
- Anchors
- Anchor bolts or straps set for the sill plate
- Dampproofing
- Applied to the outside of basement walls below grade
- Drains
- Perforated footing drain in stone, to daylight or a sump
- Slab
- 4 in. over gravel and a vapor barrier
- Backfill
- After the floor framing or bracing is in, so the walls aren't pushed in
- A
- Footing 42 in. below grade on undisturbed soil
- B
- Poured wall, reinforced per the plans
- C
- Dampproofing on the outside
- D
- Perforated footing drain in stone
- E
- 4 in. slab over a vapor barrier and gravel
- F
- Anchor bolts for the sill plate
How the job goes
Plans and layout
We price from your drawings, then lay out the foundation from the survey.
Excavation
Dig to footing depth. Ledge, water or soft soil gets dealt with as found and discussed with you.
Footings
Formed, reinforced, inspected and poured.
Walls
Wall forms set, steel and anchors placed, walls poured and stripped.
Waterproofing and drains
Dampproofing on, drain pipe and stone set, ready for backfill.
Slab
Gravel, vapor barrier and slab, once the plumbing underneath is in.
Planning prices
| Work | Planning range | What drives it |
|---|---|---|
| Footing for a deck, porch or sunroom post (42 in. deep) | $300–$750 each | Cheaper per footing on bigger layouts |
| Two-car garage foundation: frost walls and slab | $16,000–$32,000 | Size, wall height and excavation decide it |
| Addition foundation, full basement (about 300 sq ft) | $25,000–$55,000 | Footings, 8 ft walls, dampproofing and drains |
| New home foundation, full basement | $55,000–$120,000+ | Footprint, wall height, ledge and drainage design |
| Foundation crack injection, poured wall | $600–$1,500 per crack | Polyurethane for leaks, epoxy for structural bonding |
Planning ranges for Connecticut in 2026, not quotes. Ledge, tight access, long pump or wheelbarrow runs and very small pours push a job up. Your price comes in writing after we've seen the site.
Foundation work
- Additions and garages
- Full basements, crawlspaces, and frost walls with a slab.
- Porch, deck and sunroom footings
- Piers and footings to 42 inches.
- Crack injection
- Polyurethane to stop leaks; epoxy where a crack needs structural bonding.
- Exterior waterproofing
- Excavate, clean, seal and add drainage where interior fixes won't do.
- Partial wall replacement
- Failed sections removed and re-poured to an engineer's design.
- Crumbling foundations
- What pyrrhotite damage looks like and how testing works. See our guide.
Foundations in Connecticut: frost, water and pyrrhotite
Frost depth. The Connecticut State Building Code puts footings at least 42 inches below grade, statewide. Footings for decks, porches and sunrooms count too.
Water. Most basement problems in Connecticut are water problems: roof water dumped at the foundation, grading that slopes toward the house, and no footing drain. Fix the water and a lot of cracks stop mattering.
Cracks. Thin vertical cracks in a poured wall are usually shrinkage. Horizontal cracks, stair-step cracks in block, and cracks that keep widening are signs of movement and call for an engineer.
Pyrrhotite. In north-central and northeastern Connecticut, thousands of foundations poured from the early 1980s on were made with aggregate containing pyrrhotite, an iron sulfide that swells and cracks concrete over time. Map-pattern cracking is the classic sign. If that could be your house, get it tested before you repair it. Our crumbling foundations guide explains how.
Questions we hear about concrete foundations
How deep do footings have to be in Connecticut?
At least 42 inches below finished grade, the frost depth in the Connecticut State Building Code. That applies to house foundations, additions, garages and the footings for decks and porches.
Are cracks in my foundation normal?
Thin vertical cracks in poured walls are common and usually come from shrinkage. They matter if they leak. Horizontal cracks, cracks wider at one end, stair-step cracks in block, or cracks that keep growing suggest movement; have a structural engineer look.
How do you fix a leaking foundation crack?
From inside, we inject the crack with polyurethane, which expands and seals it against water. If the crack also needs to carry load, epoxy is used instead. Either is usually a one-day job.
How long does it take to pour a foundation?
For an addition or garage, footings and walls usually take one to two weeks including inspections and form work, weather permitting. A new house takes longer.
Do I need a permit for a new foundation?
Yes. New foundations are part of a building permit, and most towns inspect the footings before the pour.
What is pyrrhotite, and should I worry?
Pyrrhotite is a mineral that was in concrete aggregate from a quarry in northeastern Connecticut. Foundations poured with it can deteriorate years later. If your home is in that region and was built from the early 1980s on, testing is the first step. See our guide.
Concrete foundations by town
We build concrete foundations in 67 Connecticut towns. Pick yours for local conditions, permit notes and nearby towns.
Every dot is a town we serve.
Free concrete foundations estimates
Call or send the estimate ticket. We set a time to see the site and put the price in writing.