Foundation repair cost calculator

Foundation contractors do not quote by the square foot. They count the piers, the cracks, the slab areas to lift and the walls to brace, and price each one. We combined five cost guides for each repair. Where several give a range, the low is the middle of their lows, the high is the middle of their highs, and the typical price is the middle of their midpoints.

Modernize adds a few less common lines worth knowing: crawl space support beam repair at $1,500 to $6,000, exterior drainage at $1,500 to $4,000, and soil stabilization by grout or polymer injection at $1,000 to $5,000 or more.

Push piers and helical piers do the same job in different ways. Push piers are steel tubes driven down beside the footing using the weight of the house, until they hit firm soil or rock. Helical piers are screwed into the ground like a giant auger and suit lighter structures and porches. Pressed concrete piers are stacked cylinders used mostly under slabs. Bob Vila notes a single pier can be as little as $700 to $2,100 depending on the type, which is why two quotes with the same pier count can still differ by thousands.

Mudjacking and foam do the same job too, lifting a sunken slab by pumping material under it. Mudjacking uses a cement slurry through larger holes and costs less. Foam weighs much less, so it adds less load to soft soil, and needs smaller holes, but costs more.

Modernize's quick guide is a fair summary: small cracks or minor settling $300 to $3,000, moderate problems like uneven floors and moisture $3,000 to $8,000, and major structural work above that. A $300 crack today can become a $10,000 repair if it is left to grow.

If you know the symptom but not the fix, the problem gives a first range. HomeAdvisor and Fixr both price by the problem:

• Cracks. Thin vertical or diagonal cracks in a poured wall are common as concrete cures. Sealing them stops water. Wide cracks, stair-step cracks in block, or cracks that keep growing point to movement and need a closer look.
• Leaks. Water through cracks or at the joint between wall and floor. Fixed with crack injection, drainage and waterproofing.
• Bowing walls. Soil pressure pushing a basement wall inward, usually block. Carbon fiber straps hold mild bowing; steel beams or wall anchors handle worse.
• Settling. Part of the house sinking because the soil under it compressed, washed out or dried and shrank. Piers driven to stable soil or rock lift and hold it.

Signs worth a professional look, roughly in order of concern:

• Doors and windows that start sticking or will not latch, especially on one side of the house.
• Cracks in drywall running up from the corners of doors and windows.
• Stair-step cracks in brick or block, or brick pulling away from window frames.
• Floors that slope enough to roll a ball, or gaps opening between the floor and the baseboard.
• A basement wall leaning in, or a horizontal crack along its middle.
• Water in the basement after rain, with cracks or damp lines on the walls.

One sign alone, like a single hairline crack in a poured wall, is often nothing. Several at once on the same side of the house usually means movement, and it is worth an engineer's visit before the damage spreads.

Slabs are usually lifted with mudjacking, foam or piers under the edge. Pier and beam and crawl space homes are often leveled from underneath with new supports and shims, which is why their ranges start lower but run high when beams or joists are rotted. Basements cost the most because the walls hold back soil and water as well as the house.

Where you live matters as well. Modernize notes the Northeast runs 25% to 40% above the national average and that California is among the most expensive states, and that expansive clay soils in states like Texas and Alabama keep foundation contractors busy. The calculator's ZIP setting scales the labor share to your state's wages.

Modernize's regional ranges for a typical repair:

One corner of a slab house has dropped. There are cracks above the doors, a door that sticks and a diagonal crack in the brick. The engineer specifies six push piers along the two walls at that corner.

• Piers. 6 × $1,000 / $2,000 / $3,000 = $6,000 / $12,000 / $18,000.
• Engineer's report. $320 / $700 / $1,000.
• Permit. $75 / $113 / $150.
• Total. $6,395 to $19,150, with about $12,813 typical at the US average.

HomeAdvisor's settling range of $5,000 to $25,000 brackets it. The drywall cracks and the sticking door are usually fixed after the lift, once the house has settled onto its new piers, and are a separate cost. Enter a ZIP in the calculator to scale the labor share to your state.

Many foundation repair companies offer a free inspection. That is a sales visit by the people who will sell you the fix. A licensed structural engineer is independent, diagnoses the cause and writes the repair to be bid. Bob Vila puts the report at $300 to $1,000, HomeAdvisor at $340 to $780, Modernize at $500 to $1,000 and Fixr at $300 to $2,000. On a five-figure repair it is cheap insurance, and lenders and buyers often ask for it later.

• Ask for the cause. Soil, drainage, plumbing leaks and trees are the usual causes. A fix that ignores the cause may fail again.
• Compare like with like. Same number and type of piers, same depth or load test, same warranty.
• Read the warranty. Lifetime transferable warranties on piers are common and add value when you sell.
• Pull the permit. Fixr, Bob Vila and This Old House put it at $75 to $150. Modernize says permits and inspections can reach $500.

Most foundation movement starts with water: too much of it against the house, or the soil drying out and shrinking after a wet season. The cheapest foundation repair is keeping water under control.

• Gutters and downspouts. Keep them clean and run downspouts several feet away from the foundation.
• Grading. The soil should slope away from the house on every side.
• Drainage. A French drain or a curtain drain can carry groundwater around the house. Our French drain cost calculator prices it.
• Plumbing leaks. A leaking pipe under a slab can wash out the soil. HomeAdvisor lists plumbing pressure tests among the extras an engineer may ask for.
• Trees. Large trees close to the house pull water out of clay soil in dry spells.
• Watch the cracks. Mark the ends of a crack with a pencil and the date. If it grows, call someone.

• Price per item. Piers, cracks, slab areas and wall braces each on their own line, with the type and the depth or load spec.
• Price access. Interior piers through a finished floor, tight side yards and decks over the work area all add time.
• Include the engineer's letter when the job needs one, and the permit.
• Say what is not included. Drywall, trim and door adjustments after the lift, landscaping and plumbing repairs.
• Mind the margin. Our profit margin calculator shows the price that keeps it.

The "Save as an estimate" button above turns the result into lines. Send it from Koira and the customer can sign and pay a deposit on their phone.