Concrete
Why LA Concrete Driveways Crack — And How to Get 40 Years Out of Yours
Soil, sun, root pressure and rebar spacing. A short field guide to concrete flatwork that actually lasts in Southern California.
A properly poured concrete driveway in Los Angeles should last 30 to 50 years. Most only make it 15. The difference is almost never the concrete itself — it is what happened before and after the pour.
Prep the base like the pour depends on it, because it does
LA soil is mostly clay and decomposed granite, and both move seasonally. Without a compacted aggregate base, a slab will telegraph every millimeter of that movement into cracks within a few winters.
Four inches of well-graded base rock, compacted in two lifts, is the minimum on residential flatwork. Six inches is what we spec on anything that will see truck weight.
Rebar is not optional
Wire mesh alone lets slabs fold along cracks. #4 rebar on 18-inch centers, tied and chaired up so it sits mid-slab, holds the two sides of any inevitable crack tightly together. The crack still happens; it just stops mattering.
Control joints tell the concrete where to crack
Concrete shrinks as it cures. If you do not give it a place to relieve that tension, it invents one. Control joints — cut within 24 hours of the pour, one quarter of the slab depth, no more than 10 feet apart — direct the crack to a straight line you can barely see.
Trees, roots, and the long game
The single most common cause of premature driveway failure in older LA neighborhoods is a ficus, jacaranda, or magnolia root system that arrives ten years after the pour. A root barrier at pour time is cheap; a full replacement in year fifteen is not.