Foundation inspection cost

A foundation inspection costs $300 to $1,000, typically around $500 from an independent inspector, or $400 to $1,500 for a structural engineer's report. Foundation repair companies offer them free, and that is a sales visit that may also be a competent inspection.

Knowing which of those you are booking is most of what matters here.

What it costs

What an inspection should produce

• An elevation survey: floor heights measured on a grid across the house. This turns "the floor feels sloped" into a number and a shape, and it is the single most useful thing in the document.
• Crack mapping: where, how wide, which direction, and whether they are stepped, diagonal or vertical.
• A judgement on whether the movement is active or historic.
• The likely cause, which is drainage or soil moisture far more often than anything structural.
• Photographs.
• A recommendation with a scope, including "monitor and do nothing" where that is the answer.

Without the elevation survey, an inspection is somebody's impression.

What the cracks are telling you

Hairline vertical cracks in a poured wall, under about an eighth of an inch. Normal concrete shrinkage. Seal them to keep water out.

Stepped cracks in block or brick, following the mortar joints diagonally. Differential settlement. Worth measuring over time.

Horizontal cracks in a basement wall. Lateral soil pressure pushing the wall in. This is the serious one and it is not a monitor-and-see finding.

Diagonal cracks from window and door corners, inside and out. Movement, and the direction indicates which way.

Cracks wider at the top than the bottom, or vice versa. Tells the engineer which part of the foundation moved and in which direction.

Doors and windows that stick, floors that slope, gaps opening at the ceiling. Three of these in the same corner is a pattern; one alone is usually nothing.

Do the cheap diagnosis first

The most common cause of foundation movement is water, and the cheapest fixes come before any structural work:

• Downspouts discharging at the wall. An extension costs ten dollars and moves thousands of gallons a year away from the foundation.
• Grade sloping toward the house. Regrading is $500 to $3,000 and it is the fix more often than piers are.
• A blocked or broken drain line saturating one corner. A sewer camera at $150 to $600 finds it.
• A large tree close to the house drawing moisture out of clay soil in summer.
• Irrigation running against the foundation, which does the opposite and is just as bad.

An engineer who does not ask about all five is not doing the job. A contractor who proposes piers without addressing the water is proposing to fix the symptom.

Frequently asked questions

Is the free contractor inspection useless?

No, and it is a sales visit. Many are performed by knowledgeable people and produce accurate findings. Treat the recommendation as a proposal rather than a diagnosis, and verify anything five-figure with an engineer.

Does a home inspection cover the foundation?

Visually and briefly. A general inspector notes visible cracks and slopes and recommends a specialist. For a house with any indication of movement, the specialist visit is the one that matters.

How often should I have it checked?

There is no schedule for a house that is not moving. Walk the perimeter once a year, look at the grade and the downspouts, and note any new crack with a pencil mark and a date.

What does an elevation survey actually show?

Relative floor heights across the house, usually to a tenth of an inch. It shows the shape of the movement: a dished center, a dropped corner, a heaved middle. Each shape points at a different cause.

Should I get one before selling?

If there is any visible cracking, yes. A current engineer's report saying the movement is historic and stable is worth far more in a negotiation than arguing with a buyer's inspector about it.