Concrete Contractor in Sunnyvale, CA - Driveways and Patios Built on a Solid Base

Your price comes down to the size of the slab, what has to come out first and what the ground needs underneath, so your real number comes from the estimate visit. Hauling away the old slab, digging deeper to firm ground and adding rebar, steel inside the slab that keeps it from pulling apart if it cracks, all add cost, and so does a stamped finish over a plain broom finish, the light texture that gives shoes and tires grip. If something has to give, I'd keep the base and go plainer on the finish, because you can redo a surface later but you can't fix the ground under a finished slab.

You need an Encroachment Permit from the city if any of the work sits in the public right-of-way, the strip that holds the street and sidewalk. On many lots the sidewalk and the sloped apron down to the street aren't part of your yard, so I check where your driveway meets city ground at the estimate, and if the job touches it we help you sort out the permit before we pour.

A contractor needs a California license when a job's labor and materials total $1,000 or more, when it needs a building permit, or when it uses any additional workers. The state licensing board's small-project exemption only covers work under $1,000 that needs no permit and uses no employee labor, which a driveway or patio replacement rarely fits, so ask any contractor for their license before you sign.

Most cracks start with the ground under the slab moving, usually because the old one was poured on raked dirt that settled, or because nobody cut joints to tell the cracks where to go. Concrete does show some cracking over time, and I'd rather tell you that now than have it surprise you later. What we control is the base, dug out and packed so it holds, and control joints, shallow cuts that give the slab a straight line to crack along, which we cut on time before the slab picks its own spot.

Build the slope in before the pour, so the patio falls away from the house toward a spot where water can drain. The city's design data for building work plans for rain at 2 inches an hour, and the city says to check with it for more specific information, so on these flat lots we look at downspouts, low spots and the neighbor's side before we set forms. A patio that tips toward the house sends that water to the foundation, and that's the mistake we plan the whole layout around.

Check the city's flood zones page, which shows the parts of Sunnyvale that FEMA has marked as Special Flood Hazard Areas, places with a 1% or greater chance of flooding in any year. Those areas carry special requirements for new construction and remodeling, and the maps the city points to are dated 2009, so if your lot is in or near one, I ask the city what that means for your slab before we plan the pour.