A lasting driveway in the Austin area starts with base work matched to the ground: compacted subgrade and base on the clays east of I-35, and leveled base over uneven limestone in the Hill Country. Driveways are commonly about four inches thick with rebar, have planned control joints and need careful curing in the heat. The approach usually needs a city permit.
Last updated
Driveways are the biggest slab most Austin homeowners ever buy, and they live a hard life here. The ground under them can rise and fall with the seasons, summer pavement temperatures are punishing, and spring storms send a lot of water across them in a short time. A driveway built for those conditions can last for decades. One poured quickly on a thin base often shows cracks and sunken panels within a few years.
Know what's under your driveway
The Austin area sits on two very different kinds of ground. East of the Balcones Fault Zone, which runs roughly along I-35, the University of Texas Bureau of Economic Geology describes clay-rich blackland soils. Those clays swell when they get wet and shrink and crack when they dry, so a driveway on them is supported unevenly as moisture changes. West of the fault, in the Hill Country, limestone is often only inches below the surface. Rock doesn't swell, but it can make excavation slow, and pockets of clay or loose fill between ledges can still settle.
What goes into a durable driveway
- Tear-out and excavation. The old driveway is removed and the ground is dug to make room for a base. On rocky lots this may involve breaking rock to get a consistent depth.
- Subgrade work. Soft spots and organic soil are removed and the subgrade is compacted. On expansive clay, some contractors adjust moisture before compacting or add more select fill.
- Base. A compacted layer of crushed stone or select fill gives the slab uniform support.
- Forms and slope. The surface should drain away from the garage and house, and toward the street or a planned outlet.
- Reinforcement. Rebar on chairs is common on Central Texas driveways because it helps hold cracks tight when soil moves. It doesn't prevent cracking.
- Finishing and joints. Control joints are tooled or saw-cut on schedule so shrinkage cracks follow straight lines.
- Curing. Water curing or a curing compound slows moisture loss during the first days, which matters more in Austin's heat than almost anywhere.
Thickness and mix
Residential driveways are commonly about four inches thick, with five inches or more often recommended where trucks, trailers or RVs park. Many cities set their own minimum for the approach that sits in the right-of-way, so ask what your city requires. Mix strength, slump and admixtures for hot weather are worth discussing. The American Concrete Institute publishes hot-weather concreting guidance that many contractors follow.
The approach and the street
The part of the driveway between your property line and the street, usually called the approach or apron, typically sits in the public right-of-way. Inside the City of Austin, driveway and sidewalk work in the right-of-way must be permitted through Austin Transportation and Public Works, and the city requires the concrete work to be done by a contractor holding its Right-of-Way Contractor license. Other cities, such as Georgetown, require a driveway permit with inspections before and after the pour when you add to a driveway or change the approach. If your lot fronts a state highway, TxDOT handles access permits. Rules vary, so check with your city before work starts.
Trees and impervious cover
Austin regulates trees 19 inches and larger in diameter on residential lots, and digging in a regulated tree's critical root zone can require review. Widening a driveway also adds impervious cover, which may be limited by zoning, HOA rules or, over the Edwards Aquifer, state rules. Ask about both before you widen.
Questions to ask
- Is my lot clay, rock or fill, and how will you prepare the base for it?
- How thick will the slab and approach be, and what reinforcement is included?
- Who pulls the approach or right-of-way permit, and are you licensed for it?
- When will you pour in summer, and how will you cure the slab?
Ready to replace or add on? Request a driveway contractor, or read about repair and leveling if only part of the driveway has failed.
See how it works
Frequently asked questions
Do I need a permit to replace my driveway in Austin?
Inside the City of Austin, any driveway or sidewalk work in the public right-of-way must be permitted through Austin Transportation and Public Works, and the work must be done by a contractor holding the city's Right-of-Way Contractor license. Work entirely on your lot may have other requirements, so check with the city. Suburbs have their own rules.
How long before I can drive on a new driveway?
Foot traffic is often fine after a day or so, but contractors commonly advise keeping cars off for about a week and heavier vehicles longer. Mix and weather affect timing, so follow your contractor's guidance.
Why do so many Austin driveways crack?
Shrink-swell clay is a big reason on the east side, and fill pockets between limestone ledges on the west side. Rapid drying in summer heat, joints spaced too far apart and thin bases add to it. Some cracking is normal; good joints and reinforcement keep it tidy.
Sources and further reading
- American Concrete Institute (ACI)
- Portland Cement Association (PCA)
- Bureau of Economic Geology, UT Austin: Mount Bonnell and the Balcones Fault Zone
- City of Austin Transportation and Public Works: Right-of-Way Contractors
- City of Austin Development Services: Trees on Residential Property
- TCEQ: Edwards Aquifer rules for private residences
- City of Georgetown permits
- City of Leander: Driveway permit submittal packet
- City of Lakeway: Building applications and fees
- TxDOT Access Management Manual: Driveway permits
- Texas Department of Licensing and Regulation (TDLR)
- Texas811: Call before you dig