Repair when the slab is sound and the cause is fixed. Replace when the slab is broken up or the ground under it is still moving. The examples below use the numbers from the question and simple arithmetic. They are not our prices.
Is it cheaper to repair or replace concrete?
It is cheaper to repair today, nearly always. Whether it is cheaper over ten years depends on how long the repair survives. Published national figures put patching at $3 to $8 per square foot and new driveway work at $6 to $15, plus removal. A repair that fails in two years and is then replaced anyway cost you both bills.
- Repair: cracks are tight and level, damage is limited to the surface, one or two panels are affected.
- Replace: panels rock or have dropped, cracks are wide and spreading, the slab is thin or has no base, many areas are failing at once.
My driveway is 20 years old and one section sank by the garage. I was quoted $9,000 to replace all of it. Do I have to?
Probably not. If only the section by the garage has sunk and the rest is flat with normal hairline cracks, ask for a price to lift or replace that section alone. Backfill along a garage footing is a common soft spot in tract homes. Compare the partial price with the $9,000 figure. If the partial job is a small share of it and the rest of the driveway has years left, do the section. The new panel will not match the old color, and that is the trade.
One quote is $7,000 to repair and another is $14,000 to replace. I plan to sell in two or three years. Which makes sense?
The gap is $7,000, so ask what each buys you inside two or three years. If the $7,000 repair leaves a driveway that looks even and will pass a buyer's inspection, it is the sensible spend for a short stay. If it leaves visible patches and a sunken area, a buyer will discount for a full replacement anyway, and you will have spent $7,000 to get no credit. Ask the repair contractor exactly what it will look like when done.
I have a few long cracks and I am selling the house. Repair, replace or leave it?
If the cracks are level and narrow, clean and seal them and leave the slab. Buyers and inspectors in Southern California see cracked driveways every day. What they flag is a height difference someone could trip on, or cracks that point to slope or foundation movement. Fix those. Do not replace a serviceable driveway just before selling the house.
One contractor says tear it out. Another says pour a new layer over it. Who is right?
Ask each one what happens to the cracks. A new layer bonded to a cracked slab will crack in the same places, and it raises the height at the garage and sidewalk. An overlay is reasonable on a flat, stable slab with surface wear. Removal is right when panels have moved. If the old slab moves, the second contractor's plan fails.
The driveway is 30 years old with root cracks and I have a tight budget. Can I just grind and patch?
Yes, as a holding measure. On a tight budget, grind the raised lips so nobody trips, seal the open cracks, and replace only the worst panel if you can. Be clear with yourself that the root is still there. Put the money you save toward a full replacement later, done together with a decision about the tree.
I have lots of small cracks but nothing has sunk. Is sealing or resurfacing enough?
Usually sealing or resurfacing is enough for that. A web of fine cracks with no height change is a surface condition, often from fast drying on a hot, windy pour day. A penetrating sealer slows water getting in. If the look bothers you, a resurfacer gives a fresh face. Watch for a season first to be sure nothing is widening.
When is replacement the only sensible choice?
Replace when the slab has broken into loose pieces, when it drains toward the house and cannot be corrected, when it was poured thin on bare soil, or when repairs would cost more than half of a new slab. Replacement is also the time to fix the base, add steel and correct the slope.
Can you pour new concrete over old concrete?
You can, but it rarely makes sense outdoors. A new layer over old concrete raises the surface, which causes trouble at the garage door, the sidewalk and door thresholds. Every crack below tends to print through. A thin bonded overlay is one thing. A full new slab belongs on a prepared base, not on a failed driveway.
Can a raised edge just be ground down?
Yes, a raised edge of up to about an inch can often be ground to a smooth bevel. Grinding thins the slab and leaves a rougher, lighter patch, and it does nothing about the cause. If a root is still growing under the panel, the lip will return.
Your own price comes from a free visit, a tape measure and a written quote. Call (661) 718-4706, or text a photo of the area to the same number.