Structural and Foundation Repair

Structural and foundation repair fixes the things holding your house up when they start to fail: bowing or cracked foundation walls, a settling or sinking foundation, rotting sills and beams, failing support columns, and the cracks and uneven floors that come with them. 603 Basement Solutions diagnoses and repairs all of it across the New Hampshire Seacoast, Rockingham County, southern Maine, and northeastern Massachusetts. Unlike most contractors who sub the heavy structural work out, 603 self-performs its helical pier and structural installs in-house with its own crew. The same people who inspect your foundation are the ones who fix it and stand behind the warranty. Most repairs start with a free on-site assessment. Call (603) 610-1770.

What “structural and foundation repair” actually covers

Foundation problems are not one problem. They show up as a few distinct failures, each with its own fix and its own price range. Here is the full picture, from the wall that is bending inward to the floor that has started to slope.

A horizontal crack across a wall is not the same problem as a corner that is sinking, and a rotting sill is not the same problem as a failing column. Getting the diagnosis right is the whole job, because the wrong repair either does not hold or costs far more than the situation needs. Below, each section explains the symptom, how the repair works, and where 603’s pricing lands when the price is confirmed.

Bowing, buckling, and cracked foundation walls

A foundation wall that is bowing or buckling inward is taking a sideways load it was not built to hold. The pressure comes from saturated soil and water outside the wall, made worse in New Hampshire by freeze-thaw cycles that push on the foundation every winter. The early warning sign is a horizontal crack running roughly across the middle of the wall, where the bending stress is highest. As This Old House explains, horizontal cracks are “usually caused by the lateral pressure exerted by the soil surrounding the foundation,” and if left alone they “can lead to bowing or bulging walls.” (See This Old House on foundation wall cracks.)

How the wall is built changes the read. On a concrete block (CMU) wall, a clean horizontal crack along a mortar joint about mid-height is the classic lateral-pressure signature. A poured concrete wall more often cracks vertically as it cures or on a diagonal from a corner, so a horizontal crack in a poured wall is a louder signal that real outside pressure is at work.

The fix matches the severity of the bow, not the size of the crack:

• Carbon fiber straps are the standard repair for walls with less than about two inches of inward movement. The straps are epoxied to the inside of the wall, run floor to ceiling, and lock the wall from moving any further. 603 installs carbon fiber straps for $850 each. (For how the bonded composite resists the soil load, see SafeBasements on carbon fiber wall straps.)
• A power brace is a steel system that braces the wall against the floor structure and, in some cases, lets the wall be straightened over time. 603 installs power braces for $1,300 per brace.
• Wall anchors and steel I-beam systems are used for heavier movement, where the wall needs to be held or pulled back mechanically. These are quoted after an on-site assessment, since the engineering depends on how far the wall has moved and what is on the other side of it.
• Wall rebuilds are the last resort, reserved for walls that have failed past the point of stabilizing. This is also quoted per project.

If you are looking at a crack right now and trying to tell whether it is structural, start with why a foundation wall bows and what a horizontal crack means, or our deeper read on bowing foundation walls and why New Hampshire homeowners should not ignore them.

Settling and sinking foundations: helical piers

When part of your foundation is sitting on soil that can no longer carry it, the house starts to move. You see a corner dropping, stair-step cracks in block walls, doors and windows that stick, and floors that slope toward the affected area. The fix is helical piers: steel shafts with screw-shaped plates that a crew drives down with a hydraulic motor until the plates reach soil firm enough to hold the home. A bracket then transfers the weight of the house off the failing soil and onto the pier. Because there is no concrete to cure, helical piers go in year-round, including in a New England winter.

603 installs helical piers at $2,700 per pier for the first three, then $2,200 per pier after that, backed by a 25-year engineered warranty that transfers to a new owner (conditional on the installed work not being altered by others). A single settling corner is usually a few piers; a failing section or a full perimeter is more. This is the work 603 self-performs in-house rather than handing to a subcontractor.

Read more: how much helical piers cost and what drives the price, and when to call a professional for a sinking foundation.

Failing support columns: lally columns

Inside the basement, the steel posts that carry your main girder are called lally columns. When the base rusts, the column buckles, or it was undersized to begin with, you get sagging floors and bouncing above. A failing lally column is a quiet problem that gets loud, because everything above it depends on it. 603 replaces lally columns for $1,300 to $2,500 each, backed by a 10-year warranty, with the price depending on the load, the height, and the footing underneath.

Read more: what a lally column replacement costs, and the signs and risks of failing lally columns.

Rotting sills and support beams

The sill is the wood beam that sits on top of the foundation and ties the house frame to it. In New England’s older homes, water and insects rot it from below, and the frame starts to drop where the sill has gone soft. Because the sill carries the load of the wall above, repairs range widely depending on how much has rotted and how the house has to be supported while it is replaced. 603’s sill and beam work runs $7,000 to $40,000 depending on the length of the rot and the access. Floor support beams that have weakened are repaired or replaced in the same family of work.

Read more: why rotting sills are common in New England homes, and what a rotting sill beam replacement costs.

Crumbling fieldstone foundations

Many of the oldest homes in the region sit on fieldstone foundations: stacked stone and mortar that loosens, crumbles, and lets water through as the mortar fails. These need a different approach than a poured or block wall, because the goal is to re-bind and reinforce the stone (and often add an interior wall) rather than patch a single crack.

Read more: repairing a crumbling fieldstone foundation.

Foundation cracks and crack repair

Not every crack is structural. A thin vertical crack in a poured wall is often a shrinkage crack from curing, and it can be sealed before it lets water in. A horizontal crack, a widening crack, or stair-step cracking in block is a structural signal that needs the wall work above, not just a seal. 603 repairs non-structural cracks for $1,000 to $3,000 depending on length and access. The key is telling the two apart, which is exactly what an inspection is for.

Read more: foundation cracks and when New Hampshire homeowners should act.

Uneven, sloping, and sagging floors

Uneven floors are usually a symptom, not the root problem. A floor that slopes toward one wall can point to a settling foundation under that side; a floor that sags in the middle often points to a failing support column or a weakened beam below. The repair is whichever underlying cause is at fault, which is why a sloping floor always gets traced back to the foundation, the columns, or the beams before anything is leveled.

Read more: what to do when your floors are uneven or sagging.

Why homeowners call 603 for structural work

• We self-perform the structural installs. 603 drives its own helical piers and runs its own structural crew rather than subbing the heavy work to another company. The team that quotes your job is the team that does it and stands behind it.
• The assessment is free, and the diagnosis comes first. Most structural repairs start with a no-cost on-site assessment. You get a straight read on what is actually failing and what it takes to fix, not a one-size quote.
• Confirmed, per-method pricing. Carbon fiber straps at $850 each, power braces at $1,300 each, helical piers at $2,700 for the first three then $2,200, lally columns at $1,300 to $2,500, crack repair at $1,000 to $3,000. Heavier work is quoted on site so the number matches your actual house.
• Warranties that transfer. The helical pier work carries a 25-year engineered warranty that transfers to a future owner, and lally column work carries a 10-year warranty. A documented, warrantied foundation repair is a selling point when you list the home, not a red flag.
• Licensed and insured, and local. 603 is licensed and insured and works out of East Kingston, NH, across the Seacoast and into southern Maine and northeastern Massachusetts.

Where 603 works

603 Basement Solutions provides structural and foundation repair across the New Hampshire Seacoast and Rockingham County, southern Maine, and northeastern Massachusetts, from its base in East Kingston, NH. If your foundation is moving, cracking, sinking, or sagging, the next step is a free on-site assessment. Call (603) 610-1770 or request a visit.

Get a free foundation assessment →

Explore the repairs in depth: bowing and cracked walls · foundation cracks · helical piers cost · lally columns · rotting sills · fieldstone foundations · uneven floors

Frequently asked questions

What is structural and foundation repair?

It is the repair of the parts of a house that carry its weight and keep it stable: foundation walls, the footing and soil under them, support columns, sills and beams, and the slab. It covers bowing or cracked walls, settling and sinking foundations, failing lally columns, rotting sills, crumbling fieldstone, and the cracks and uneven floors that come with those problems. 603 diagnoses and repairs all of it, starting with a free on-site assessment.

How do I know if a foundation crack is structural or cosmetic?

A thin vertical crack in a poured wall is often a harmless shrinkage crack from curing. A horizontal crack, a crack that is widening, or stair-step cracking in a block wall is a structural signal that the wall is under pressure or the foundation is moving, and it needs more than a seal. The reliable way to tell is an inspection. 603 repairs non-structural cracks for $1,000 to $3,000 and prices structural wall work after seeing the wall.

How much does foundation repair cost in New Hampshire?

It depends entirely on the problem. 603’s confirmed pricing: carbon fiber straps for a bowing wall are $850 each, power braces are $1,300 each, helical piers are $2,700 per pier for the first three then $2,200 after, lally columns are $1,300 to $2,500 each, and crack repair runs $1,000 to $3,000. Sill and beam work ranges from $7,000 to $40,000 depending on how much has rotted. Heavier structural work, like wall anchors, steel I-beams, or a wall rebuild, is quoted after an on-site assessment.

Does 603 do the structural work itself or use subcontractors?

603 self-performs its structural installs in-house, including helical piers, with its own crew. Most foundation companies sub the heavy lift out to another contractor. With 603, the team that inspects and quotes your foundation is the team that does the repair and is accountable for the warranty.

How serious is a horizontal crack in my basement wall?

It is structural, not cosmetic. A horizontal crack across the middle of a foundation wall almost always means the wall is bowing inward under pressure from the soil and water outside it. Caught early, most bowing walls are stabilized from the inside with carbon fiber straps ($850 each) without replacing the foundation. Left alone, the wall keeps moving and the repair gets larger. This is worth an inspection sooner rather than later.

Do you offer a warranty on foundation repairs?

Yes. Helical pier work carries a 25-year engineered warranty that transfers to a new owner, as long as the installed work is not altered by others. Lally column replacements carry a 10-year warranty. A documented, warrantied repair can help rather than hurt when you sell the home.

What areas does 603 serve for foundation repair?

603 Basement Solutions works across the New Hampshire Seacoast and Rockingham County, southern Maine, and northeastern Massachusetts, from its base in East Kingston, NH. Call (603) 610-1770 for a free on-site assessment.