Most Vacaville homes sit on a concrete slab or a short perimeter foundation, and full basements are uncommon. Many of the worries below come back to the same clay soil that moves driveways. Some need a concrete contractor, some need a structural engineer, and we tell you which.
The dollar figures here are national ranges that HomeGuide published for 2026. They are not quotes from us. Solano County labor rates, the price of ready-mix on the day and what we find on your lot all shift the real number. Last checked October 2026.
Are cracks in my foundation serious or cosmetic?
Thin vertical or hairline cracks in a foundation are usually cosmetic shrinkage. Signs that a foundation crack is serious are a width greater than about a quarter inch, one side offset from the other, a crack that widens toward one end, horizontal cracks in a wall, and doors or windows inside that have started to stick. Mark the ends with a pencil and a date and watch through a wet and a dry season. A structural engineer should look at anything on the serious list.
National figures for foundation repair are $250 to $800 for minor crack repairs, $2,000 to $12,000 to fix foundation leaks, and $4,500 to $20,000 for settling, sinking or bowed walls.
My front steps are pulling away from the house. What causes that?
Steps pulling away from the house are usually sitting on backfill that has settled or on clay that has shrunk. Steps are often poured separately from the foundation and are not tied to it, so they drop and tilt on their own. If the steps are sound they can sometimes be lifted and the gap sealed. If they have cracked or the rise of each step is now uneven, replacing them on a proper base, pinned to the foundation, is the lasting repair.
My garage floor dropped on one side. Is that a leveling job or a foundation problem?
Usually a leveling job. In most houses the garage floor is a separate slab that floats inside the foundation walls, so a floor that has dropped or sunk on one side generally means the fill under it settled. If the garage walls are straight and uncracked and only the floor moved, lifting or replacing the slab deals with it. If the walls, the door opening or the house slab show cracks too, bring in an engineer before any concrete work.
My retaining wall is leaning after heavy rain. Is it going to fail?
A retaining wall that starts leaning after heavy rain is under water pressure it was not built to handle, and it should be looked at soon. Saturated clay is very heavy. Check whether the drain holes are blocked and whether water is ponding behind the wall. Keep people and cars away from the low side. A slight lean that is stable can sometimes be held with better drainage. A wall that is moving, cracked or bulging usually has to be rebuilt with a proper footing, steel and a drain behind it.
I was quoted $18,000 for piers and $1,500 to seal the crack. Which is right?
They fix two different things, so first find out which problem you have. Sealing for $1,500 stops water coming through a crack that is not moving. Piers for $18,000 support a foundation that is sinking. This question usually comes from homes with a basement wall, which few houses here have, but the logic is the same for a slab or stem wall. Pay an independent structural engineer for an inspection before choosing. An engineer has nothing to sell and the fee is small against a $16,500 gap.
My slab floor is damp or shows white powder. Is it leaking?
White powder on a slab or a foundation wall is efflorescence: salts left behind when moisture moves through concrete and dries at the surface. It shows that water is getting in, not that the concrete is failing. In a house with a basement the same thing appears on the walls. Find the water source first. Common ones here are sprinklers against the house, soil graded toward the wall, a missing vapor barrier and plumbing leaks under the slab. A sudden damp patch with a rising water bill needs a plumber's leak test.
Does a retaining wall need a permit or an engineer?
Under the California Building Code, a wall over 4 feet from the bottom of the footing to the top, or any wall carrying a surcharge such as a driveway or slope above it, needs a permit, and such walls generally need engineered drawings. Seismic design is part of that. Our permits page has the detail.
Does insurance cover a retaining wall or slab?
Often not. A standard homeowners policy generally covers sudden events it names, and commonly excludes earth movement, settling, cracking, wear and flood. Earthquake damage needs a separate earthquake policy and flood damage a separate flood policy. A wall knocked down by a vehicle or a fallen tree may be covered. Read your policy and ask your agent before assuming either way. If you do claim, take photos before any cleanup and get a written repair quote.
To get an actual price for your job, ask for a free on-site estimate. We measure, look at the soil and the access, and put the quote in writing. Call (707) 385-5848 or text a photo of the area.