Most cracks in house concrete are cosmetic, and a few are structural. On Concord clay the test is whether the crack is moving. This page covers the questions we hear most. For structural work we follow an engineer's design.
The dollar figures on this page are national ranges that HomeGuide published for 2026. They are not quotes from us. What you pay in Concord depends on local labor and material prices, access to the site and the clay under the slab. Last checked October 2026.
Are cracks in my foundation serious or cosmetic?
A thin vertical crack that has not changed in years is usually cosmetic shrinkage. A foundation crack is more serious when it is wider than about a quarter inch, wider at one end, stepped or horizontal, or when doors stick and interior walls crack nearby. Mark the ends with a pencil and date them. If it grows over a wet and dry season, have a structural engineer look. National figures put minor foundation crack repairs at $250 to $800 and work for settling or sinking at $4,500 to $20,000.
My front steps are pulling away from the house. Why?
The steps sit on shallow soil and the house sits on deeper footings, so they move by different amounts. Clay shrinks at the outer edge in summer, the steps tip away and a gap opens at the top. If the steps are in one piece they can sometimes be lifted and the gap sealed. Otherwise they are rebuilt on a proper base and pinned to the foundation.
My garage floor has dropped on one side. Is that a leveling job or a foundation problem?
Look at the walls. In many houses the garage floor is a separate slab poured inside the footings. If only the slab has dropped and the walls, door frame and ceiling line are straight, it is usually a leveling or replacement job. If the wall or footing has gone down with it, with cracks in the stucco or a door opening out of square, that is a foundation matter for an engineer.
My retaining wall is leaning after heavy rain. Is it dangerous?
A retaining wall leaning more after rain is a warning sign. Wet clay behind a wall is far heavier than dry soil, and a wall with blocked or missing drains takes the full push. Keep people and cars away from the low side, look for plugged weep holes and call someone to assess it. Some walls can be relieved with drainage and tied back. A wall that has rotated a lot is rebuilt with a footing and drains to an engineer's design.
One company quoted $18,000 for piers and another $1,500 to seal the crack. Which is it?
Those two prices are for two different problems, so find out which problem you have before you spend either. Sealing for $1,500 treats a crack that leaks but does not move. Piers for $18,000 treat a foundation that is sinking. An independent structural engineer who sells no repairs can measure the floor levels and tell you. The fee for that visit is small beside either quote.
My slab floor or basement wall shows damp spots or a white powder. What is it?
The white powder is efflorescence. Moisture moves through the concrete, dries at the surface and leaves mineral salts behind. It is not harmful in itself, but it shows that water is getting in. Few Concord houses have basements, and here it mostly appears on garage slabs and low stem walls in winter. Start outside: fix gutters, extend downspouts and slope soil away. National figures for fixing foundation leaks are $2,000 to $12,000.
How deep do footings need to be here?
The building code and the soil set footing depth here. Frost does not, because the ground in Concord does not freeze to any depth. On expansive clay an engineer or the soils report may call for deeper or wider footings than the code minimum. Structural footings are inspected by the building department before the pour.
Does a new retaining wall need drainage?
Yes, every time. A wall should have drain rock behind it, a perforated pipe at the base or weep holes through the face, and a way for surface water to run around the wall and not over it. More walls fail from water pressure than from weak concrete.
The real number for your job comes from a free visit, where we measure and look at the ground. Call (925) 690-1468 or text a photo of the area.